Engine cutout on throttle off

Rick G · 51 Re: Engine cutout on throttle off Wed Aug 13, 2014 10:48 am

Rick G

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I only re glued my grip because it had worked its way up against the switch block and was binding a bit when I had my gloves on and my hand was pushing it up a bit more so I glued it so there was 1/4 inch clearance.
You may not need to adjust the butterflys but get it idling smoothly by adjusting the idle screws (the big brass ones) then set the TPS. Even using the choke to adjust it as the choke lever will only move the throttle very slightly for about a 1/4 turn, it is far more sensitive than the twist grip for setting the TPS.

Holister · 52 Re: Engine cutout on throttle off Wed Aug 13, 2014 11:26 am

Holister

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I'll have a look at those adjustments but to be honest, atm she's starting and idling very well (960rpm & about 1800 fast idle) so for the time being I think I'll leave well enough alone.

My query was regarding the difference between the throttle>TPS switching in fairly spot-on (by ear) but you say that my choke>TPS is switching in way too late.... but imho I think we can rule out the TPS as the culprit for now

I've read up on throttle boddies and will inspect the boots over the w/end. As far as syncing the butterflyies... looks relatively simple if I had the euipment but I think I have other priorities atm and as I've said, she does run pretty smooth atm anyway.

I'm trying to find time to clean all the elec. connections before moving on. So it'll be a w/end job by looks of it. Also doing a cooling system clean plus air and oil filter on w/end as well.

Cheers

Holister · 53 Re: Engine cutout on throttle off Wed Aug 20, 2014 12:41 pm

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UPDATE:
Problem still occurring

SYMPTOMS: (so you don't have to read all the posts above)
Accelerator off > clutch disengaged (lever in) > engine dies.
Choke can be on or off.
Engine hot or cold.
Can save it by opening throttle.
Battery light comes on almost straight away after clutch in.
Can restart in-gear with clutch in with starter or roll-start if still moving.
Doesn't happen under normal operation as the clutch is only disengaged momentarily while changing gears and/or acclerator is open.
Conditions under which this issue occurs for example are under hard braking when you keep the clutch disengaged while you lay on the brakes or you want to roll to a stop with clutch in.
Won't happen if reves are below about 2 or 3 k.

WHAT I'VE CHECKED OR DONE SO FAR:
Disconnected TPS. No change
Cleand TPS plug/socket connections. There was corrosion on the middle terminal. Made no difference after cleaning.
Confirmed with meter that TPS is switching in uand out at correct throttle positions.
Cleaned as many electrical connections as I could find from the ICU back to the ECU under the tank including the main earth connection.
I've sprayed electrical cleaner on all connectors, brushed where possible and applied WD40 sparingly. I've not cleaned the ignition switch.
Vent tube recently replaced.
Engine runs rough and nearly dies on removal of oil filler cap.
No fuses blown.
Plugs not fowled. I haven't changed them. They look ok and as performance described below is good, they are not suspect.
12.8 v across bat and 13.8v @2000rpm.
Battery shop says the bat is good and was installed in the bike Nov 2013.
Clutch and throttle controls have been cleaned and lubed.
Engine starts easily and idles smoothly.
Engine revs out and delivers good power as expected accros the range.
Instruments all working. Running lights function.

CONCLUSION:
While there are still some things that could be checked such as coils, alternator, TB sync, timing and injectors etc I think the next logical step would be to try a different ECU. Anyone able to help me out with that? I'm hoping to to be travelling down to Sydney sometime middle Sept. I'm in Ballina/Lennox Head if anyone is passing thru or could meet up somwhere.

Thanks to everyone for the time and thought put into this.
Cheers

92KK 84WW Olaf · 54 Re: Engine cutout on throttle off Wed Aug 20, 2014 1:02 pm

92KK 84WW Olaf

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A lot seems to happen when you pull the clutch lever and its common to a lot of the cut outs..

Check the routing of the clutch cable under the tank. This area is full of electrics and connectors.When you pull the lever the cable will move slightly. If the routing is incorrect it could cause electrical issues. This may move enough to disturb an electrical connection under the tank and it can also disturb the connection to the ECU up under the headstock. The cable and the earths are close to each other under the centre of the tank and its not impossible that the movement of an incorrectly or even correctly routed cable cable could be disturbing an electrical connection only when it is moved.

rawdonball · 55 Re: Engine cutout on throttle off Wed Aug 20, 2014 6:04 pm

rawdonball

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Hi Kaptain,

I have a Parts bike sitting with Ray Peak just 140km North of you. If you have time to take a ride up that way, you are welcome to try out ICU or any other bits which might be of interest. It is beautiful country up that way and Ray is not referred to as the 'BMW wisperer' for nothing! He is in Wonglepong a few kms from Canungra.
I would be looking to check that the sudden depression of intake pressure is not killing your fuel pressure via a faulty fuel pressure relief valve. I can't imagine the mechanics of such a failure but your problem sounds amaizingly consistent for an electical fault of the type associated with poor connections and physical movement.

I can PM you his details if you are in a position to try this

japuentes · 56 Re: Engine cutout on throttle off Wed Aug 20, 2014 7:19 pm

japuentes

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Hi, I would check the MAF´s by pass screw setting, using the lean drop method for CO adjust.
I had the issue and solved it adjusting the injection via this method.
And the site has a lot of useful info.
Hope this helps
Best regards
JAP

charlie99 · 57 Re: Engine cutout on throttle off Wed Aug 20, 2014 9:29 pm

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might be an idea to add the afm to the list

the afm does several things like air temp sensor on the input of it , and the wiper sometimes becomes intermittent , but being a later version "should" have the modified wiper cable installed ...but no where near guaranteed that it is there ...of course the bypass airflow for idle is in there also .

this then connects to the under seat computer ..

robmack · 58 Re: Engine cutout on throttle off Wed Aug 20, 2014 9:53 pm

robmack

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The symptoms appear as if power is suddenly cut to some critical component needed for keeping the engine running -- coils, or injectors, or fuel pump. It seems like a catastrophic loss of electrical power which gets recovered if the throttle reopens. The charge indicator coming on almost immediately upon chopping the throttle and pulling in the clutch is a symptom of power loss.

Let's assume the clutch getting pulled in is a red herring. Possibly, the throttle is being chopped at the same time the clutch is being pulled; afterall its a panic stop. It only happens under conditions of prolonged throttle closure. Electrically, the only connection to this mechanical change in the condition of the engine is (1) the TPS is closed and (2) the Hall Sensors feedback decreasing RPMs to the ICU. The MAF will register a closure of its vane because the throttle closure will demand less air, and feed that changing vane position to the ECU. Same with the ICU feeding status of decreasing RPMs to the ECU, so that the ECU can decide to cut power to the injectors until RPMs decrease below 2000.

The only conclusion I can draw from this series of events is the ECU is acting up. If the ECU was failing, it could possibly cut power to the injectors under engine braking but fail to restore power to them when needed. And the only way to categorically eliminate the ECU as a failing component is to substitute it for a known working unit and see if the symptoms move with the failed ECU or remain with the bike.

Does anyone see a flaw to my logic?

Rick G · 59 Re: Engine cutout on throttle off Wed Aug 20, 2014 10:26 pm

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That fairly much sums up my conclusion to that Rob in that it is getting the right feedback to cut the injectors until below 2000rpm but doesn't get the signal to restart the injectors quickly enough because when the clutch is left engaged it all works fine because the engine keeps turning till the ECU figures that the engine should be getting fuel.
That is why I though earlier on that it may have been dirty contacts in the TPS and they it was taking its time getting a signal through because the voltage had to break down the resistance of the dirt before it became high enough for the ECU to recognize it. Looking back Nigel has shown that it is not that but possibly a similar syndrome.
I don't think it is the panic stop but that when you are coming to a stop under the "normal" situation you blip the throttle at each down change and that reduces the possibility of the engine stopping where in a Panic stop it is that the throttle in not being used.
BTW Nigel I now have a working ECU if you want to come for a ride up the hill we can try it.

ReneZ · 60 Re: Engine cutout on throttle off Thu Aug 21, 2014 9:34 am

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I'm with Rob/Rick. It still could be that the TPS is OK, but the wiring of it fails, but most likely the ECU is or not functioning as it should or not receiving the right signal(s) as above. Did you test fumbling with the wiring (also under the tank) whilst the engine runs to see if anything changes. It could be a broken wire behind a connector or damage to the shield of the HES wire etc.
This is a funny one!

92KK 84WW Olaf · 61 Re: Engine cutout on throttle off Thu Aug 21, 2014 9:47 am

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ReneZ wrote:I'm with Rob/Rick. It still could be that the TPS is OK, but the wiring of it fails, but most likely the ECU is or not functioning as it should or not receiving the right signal(s) as above. Did you test fumbling with the wiring (also under the tank) whilst the engine runs to see if anything changes. It could be a broken wire behind a connector or damage to the shield of the HES wire etc.
This is a funny one!

For what's its worth my money is on this scenario too. It won't be the first time using the clutch has temporarily broken a connection in damaged wire or connector. As you have an opportunity to swap the ECU I would try that option too.

The earths converge under the tank and the ECU works by making a connection to earth. If the clutch cable was to interfere with an earth connection it can cause this problem. Been there!

charlie99 · 62 Re: Engine cutout on throttle off Thu Aug 21, 2014 9:54 am

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ReneZ wrote:I'm with Rob/Rick. It still could be that the TPS is OK, but the wiring of it fails, but most likely the ECU is or not functioning as it should or not receiving the right signal(s) as above. Did you test fumbling with the wiring (also under the tank) whilst the engine runs to see if anything changes. It could be a broken wire behind a connector or damage to the shield of the HES wire etc.
This is a funny one!

to "fumble" under the tank with bike running ...many of us have extended the fuel lines ...with appropriate rated tubing ...by just an inch or two ...( easiest by replacing the fuel line on the feed line to the fuel rail).

makes thing easier ..in the long run

Holister · 63 Re: Engine cutout on throttle off Thu Aug 21, 2014 9:55 am

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rawdonball wrote:Hi Kaptain,

I have a Parts bike sitting with Ray Peak just 140km North of you. If you have time to take a ride up that way, you are welcome to try out ICU or any other bits which might be of interest. It is beautiful country up that way and Ray is not referred to as the 'BMW wisperer' for nothing! He is in Wonglepong a few kms from Canungra.
I would be looking to check that the sudden depression of intake pressure is not killing your fuel pressure via a faulty fuel pressure relief valve. I can't imagine the mechanics of such a failure but your problem sounds amaizingly consistent for an electical fault of the type associated with poor connections and physical movement.

I can PM you his details if you are in a position to try this

Thanks for the offer rawdonball
I have an old mate at Beechmont I visit occasionally. Its a great excuse to go for a run over the Burringbar Ranges between here and Murwillumbah and then up the Numunbah valley into QLD. A great ride.

robmack wrote:..... The only conclusion I can draw from this series of events is the ECU is acting up. If the ECU was failing, it could possibly cut power to the injectors under engine braking but fail to restore power to them when needed. And the only way to categorically eliminate the ECU as a failing component is to substitute it for a known working unit and see if the symptoms move with the failed ECU or remain with the bike.

Does anyone see a flaw to my logic?

Your logic sounds fine to me robmack and probably been the most likely cause all along. I just had to rule out all the other smaller possibilities first. I have studied the elec schematics for hours trying to get a handle on the sequence of events leading to a shutdown. Unfortunately, not being a mechaic and not familiar with the K engine, I just can't get my head around it.

You said... "so that the ECU can decide to cut power to the injectors until RPMs decrease below 2000." I think this is where to issue is. The ECU is not initiating fuel to the injectors when it gets the signal from the TPS. Open the throttle and it gets this signal via another route.

One thought coming to mind this evening is that I should try to replicate this problem while in neutral. That would rule out any connection with the clutch. I would assume TPS/ECU would still be functioning as normal. Any thoughts? I'll try this first thing in the morning. I don't think the neighbours would appreciate that lovely noise right now (10.30pm here now) Laughing

RicK G wrote:.... I don't think it is the panic stop but that when you are coming to a stop under the "normal" situation you blip the throttle at each down change and that reduces the possibility of the engine stopping where in a Panic stop it is that the throttle in not being used.
BTW Nigel I now have a working ECU if you want to come for a ride up the hill we can try it.

Correct. By working down the gears the throttle is never off therefore fuel will always be available.

I appreciate the offers of an ECU for testing and will take someone up on that offer shortly. Let me work out my movements over the next few weeks and I'll get back to you. No urgency at this point.

Just out of curiosity and because I really like to drill down on stuff like this, can someone point me towards detailed info on the ECU such as circuit diagrams, connector wiring info etc etc. My Bro is a bit of an electronics wizz and he's been able to fix stuff for me in the past with a little electronic trouble shooting and replacing circuit board components. He's keen to have a look at it.

Cheers and thanks for everyone's input.

Holister · 64 Re: Engine cutout on throttle off Thu Aug 21, 2014 10:16 am

Holister

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92KK K100LT 193214 wrote:

ReneZ wrote:I'm with Rob/Rick. It still could be that the TPS is OK, but the wiring of it fails, but most likely the ECU is or not functioning as it should or not receiving the right signal(s) as above. Did you test fumbling with the wiring (also under the tank) whilst the engine runs to see if anything changes. It could be a broken wire behind a connector or damage to the shield of the HES wire etc.
This is a funny one!

For what's its worth my money is on this scenario too. It won't be the first time using the clutch has temporarily broken a connection in damaged wire or connector. As you have an opportunity to swap the ECU I would try that option too.

The earths converge under the tank and the ECU works by making a connection to earth. If the clutch cable was to interfere with an earth connection it can cause this problem. Been there!

The TPS checks out ok
There should be no movement in the clutch cable if fitted and adjusted correctly. Mine's pretty solid and there's no movement under the tank.
If there was some sort of loose connection the fault would be intermitant and this fault is NOT intermittant. It occurs under specific conditions and is replicable. Anyway just to rule the clutch cable out of the equation I'll try to replicate the issue with the motor in neutral.
I've taken the under tank earth terminal off and cleaned the terminals as discribed previously. There was no real issue with it anyway, I just went over all connections I could find under the tank and elswhere.
Cheers

92KK 84WW Olaf · 65 Re: Engine cutout on throttle off Thu Aug 21, 2014 10:43 am

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You are very correct in that there should be no movement if the clutch cable is routed correctly. When I got the RT the clutch cable installed by a previous owner was routed incorrectly and was moving about. Plus some of the cable ties on the loom were missing and some of the loom was cable tied to the clutch cable. I also see the fault is not intermittent and can be replicated. It was just that it seemed to be happening when you use the clutch. If this is happening all of the individual components are likely to check out ok. I was looking at a k75 during the week and a cut out problem turned out to be the connector block to the computer under the seat and no defective components. A clean up and all was fine.

However there is also an elecrtical connection on the clutch lever but my understanding is that only inhibits the starter and has no further function once the engine is running?

Rabidchiwawa007 · 66 Re: Engine cutout on throttle off Thu Aug 21, 2014 1:45 pm

Rabidchiwawa007

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Inge K. wrote:

duck wrote: Probably engages the starter too but I don't think the sprag isn't going to catch up to an engine running at high RPMs.

The ground connection on the starter relay coil is disabled when the engine is running higher than 711 rpm's.

Huh, I can press the starter button on my '92 k100rs while it's above 711 rpm and hear the starter spin right up. I haven't tried it in gear, but it'll spin up at idle with the choke on too. Maybe something's wrong scratch

robmack · 67 Re: Engine cutout on throttle off Thu Aug 21, 2014 2:11 pm

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Rabidchiwawa007 wrote:Huh, I can press the starter button on my '92 k100rs while it's above 711 rpm and hear the starter spin right up. I haven't tried it in gear, but it'll spin up at idle with the choke on too. Maybe something's wrong

Did the previous owner modify the start circuit so that one side of the start relay is tied to the frame? On a stock wiring harness, one side of the start relay coil goes to the right hand control connector, the other side goes to the ignition control unit. It's the ICU which disables the start relay if the hall sensor tells it that the engine is spinning faster than 711 RPM.

Inge K. · 68 Re: Engine cutout on throttle off Thu Aug 21, 2014 6:44 pm

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Rabidchiwawa007 wrote:

Inge K. wrote:

duck wrote: Probably engages the starter too but I don't think the sprag isn't going to catch up to an engine running at high RPMs.

The ground connection on the starter relay coil is disabled when the engine is running higher than 711 rpm's.

Huh, I can press the starter button on my '92 k100rs while it's above 711 rpm and hear the starter spin right up. I haven't tried it in gear, but it'll spin up at idle with the choke on too. Maybe something's wrong

This interlock is only present on Jetronic euqipped models (2V).

Holister · 69 Re: Engine cutout on throttle off Thu Aug 21, 2014 7:57 pm

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92KK K100LT 193214 wrote:…. However there is also an elecrtical connection on the clutch lever but my understanding is that only inhibits the starter and has no further function once the engine is running?

Although the clutch does play a small part in the system's electrics and this fault is likely to be electical and it occurrs only while the clutch lever is in, I doubt it (the clutch) plays any part in this issue except for its part in disengaging the engine from the rear wheel allowing the enugine revs to fall back to idle. As robmack said… "let's assume the clutch is a red herring". I'll go a step further and try to replicate the issue without using the clutch thereby eliminating it from the equation.

I hear what you are saying about connections etc and so will check all again in context of cable route and ties etc. Thx

You mentioned "previous owners"…. they have a lot to answer for don't they. Mad

My old girl is in pretty good shape but has suffered a little neglect for I suspect around 5 to 10 years. Im slowly fixing all her bits and bobs as I go.

Cheers

Holister · 70 Re: Engine cutout on throttle off Fri Aug 22, 2014 9:28 am

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Double checked all connections and clutch cable routing. All looks good.

However, I did a test with the engine in neutral and could not replicate the problem. This surprised me (probably because I haven't a damn clue what's going on Shocked

).

Bike stationary.
Gearbox in neutral.
Open throttle to 5,000rpm
Snap throttle off.

Result: engine eases smoothly down to idle.

I did this several times and even tried pulling the clutch lever in just after throttle closed... same result. No shutdown. So this only happens when the box is in gear.

I remember reading somewhere about the diode between the clutch switch and the neutral light which comes off the gear indicator and thought then that this may be playing some part. So untill I get my hands on another ECU I will follow this lead for now. Testing and replacing the diode should be relatively simple once I get the instruments off.
I'll get my Mr McGoo glasses out and study the elecrical schematics again tonight.

Any thoughts??

Cheers

92KK 84WW Olaf · 71 Re: Engine cutout on throttle off Fri Aug 22, 2014 9:36 am

92KK 84WW Olaf

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Advice? Have a beer while you're waiting to swap the ECU.

Holister · 72 Re: Engine cutout on throttle off Fri Aug 22, 2014 12:02 pm

Holister

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92KK K100LT 193214 wrote:Advice? Have a beer while you're waiting to swap the ECU.

Now that's the best sort of advice. Having a beer will take your mind of the problem for a while, allowing the subconscious to mull things over and work out a solution.
I had a really nice Aussie IPA this evening. Nothing came to me Shocked

. So then I cracked a Guiness.... nup. Still nuthin'.
Must've been a crook batch. Laughing

Oh well. I'll try again tomorrow evening.
Engine cutout on throttle off - Page 2 502531

Cheers

Inge K. · 73 Re: Engine cutout on throttle off Fri Aug 22, 2014 12:26 pm

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Kaptain Holister wrote:I remember reading somewhere about the diode between the clutch switch and the neutral light which comes off the gear indicator and thought then that this may be playing some part. So untill I get my hands on another ECU I will follow this lead for now. Testing and replacing the diode should be relatively simple once I get the instruments off.

The diode just prevents the neutral light from coming on everytime you pull the clutch.

MikeisonTV · 74 Re: Engine cutout on throttle off Sat Aug 30, 2014 3:10 pm

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Well Team, the shared symptom of my 92 K75 just got worse and may shed some light on a solution. The k75 would do the same as Kaptain's when u pull the clutch in to down shift she would die. If u pulled it back in, hit the start button, and dropped the clutch she fire without skipping a beat.

Yesterday, I was driving her a bit on the highway and thought why not open her up for a few miles...maybe the increase pressure through the fuel line might dislodge any obstruction that maybe the cause of our cut off. I reached my destination at warp speed with no prob. My ride home was not so epic.

I drove several miles at 65 before she started dropping power. It felt like I rolled the throttle off went I was just cruising. Then it would return on its own, obviously making the bike lurch forward. After a dozen of these sphincter pucker moments she died. The normal rolling start wasn't happening.

I pushed her off the highway. First thought I was out of gas. It was low, but not in the danger zone. I pushed her to the nearest gas station. Put in half a tank. After a small temper tantrum she fired. My next stop was a mile away.

After this 30 minute stop, I climbed back on her for the final..."push" home. After another 5 miles the lurching returned. I was able to get her to fire via rolling start several times which bought me another 2 miles to my exit. She died at the end of the exit ramp. Whined and whined with no engine fire.

I pushed her to secure location and hiked home as it was 2 AM and I was over pushing and drama. Does the maybe feel like a fuel like obstruction that gets lodged under pressure? I replaced the fuel pump and filter trying to solve the original prob Kaptain's and I are sharing. Thoughts?

charlie99 · 75 Re: Engine cutout on throttle off Sat Aug 30, 2014 4:27 pm

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certainly sounds like a pressure loss
we have seen the fuel pressure regulator play up on several machines with very similar types of symptoms

Rick G · 76 Re: Engine cutout on throttle off Sat Aug 30, 2014 8:46 pm

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Fuel pressure regulator is where I would be looking next.

Rabidchiwawa007 · 77 Re: Engine cutout on throttle off Sat Aug 30, 2014 11:15 pm

Rabidchiwawa007

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Just to chip in on some other things to check / possible causes as I've had quite a bit of cut-out issues in the past and it was always a different cause.
-ignition switch: try wiggling the wires at the base while the bike is on, see if it drops or cuts out a bit.
-kill switch: this has probably been covered in the thread, but they're notorious for getting dirty or wearing out and becoming a loose connection.
-hall sensor: the bane of my existence.
-ignition coils: they may be arcing to each other or the engine case behind them.
-loose battery connection: probably also already covered.
-side stand switch: if it's faulty, it'll cut power to the bike. I ended up just spicing my wires together there.
-loose blade connectors at fuses: Long shot, but possible.
-fuel filter was mentioned, but also check the PRE-filter, which is on the bottom of the fuel pump itself. Pretty easy to get at. Just disconnect the battery before messing with the contacts in there :bom:

MikeisonTV · 78 Re: Engine cutout on throttle off Sun Aug 31, 2014 1:20 am

MikeisonTV

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Engine cutout on throttle off - Page 2 178468

Update...well if anyone has a badge of douchetardery I need to borrow it so I can wear it. I removed the gas cap and shazam...the neg line on the fuel pump was loose. No more sputter...now back to this cutoff issue. I have developed a massaging of the clutch technique that prevents cutoff, but makes her high maintanence to ride...

Holister · 79 Re: Engine cutout on throttle off Tue Sep 02, 2014 10:43 am

Rabidchiwawa007

wizzard · 80 Identical problem Fri Sep 12, 2014 4:30 pm

wizzard

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Would you believe I'm having the identical problem of coming to stuff like tee junctions and the engine dieing as I clutch in and allow the revs to drop. Also in acceleration circumstances it sometimes gives a big hiccup. Where my story differs, is that my K100 engine is in a Grinnall Scorpion trike, so its got a foot clutch, Ford steering column and ignition key, 2 fuel pumps and a few other differences from the bike. The car came with a diary of its life dating back to 1995, and as far back as that a problem of the engine cutting out on left hand bends (!) was recorded. When my friend bought the car in 2005 he noted that it cut out sometimes on the test drive. Since then it has only done 4000 miles, and has lain idle for a long time. The first owner tried everything to resolve the issue, with no great success, as did the 2nd owner. I'm now working through everything - the ECU has been replaced, as has the ICU, filters, earths checked and cleaned, etc , etc. If anything the problem is becoming worse. I too can replicate the problem, but I dont need to be moving - sometimes I can leave it ticking over perfectly for ages (with an auxiliary fan keeping the temp at 85 degrees), then suddenly it will cut out.
Another oddity - my exhaust manifold is heat wrapped. I can drive for a while and have no problem, but if I push it a bit more the heat wraps starts cooking, which I reckon means the engine is leaning out badly for some reason, but again this doesnt happen all the time.
I hope someone can resolve this as its getting worse steadily, and its costing me an arm and a leg buying bits that are not helping.
Wizzard

robmack · 81 Re: Engine cutout on throttle off Fri Sep 12, 2014 7:53 pm

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Very peculiar thing, but today I was reading posts on the Wildgoose site (dedicated Moto Guzzi forum) and came across an older post which spoke of exactly this problem (engine dying when pulling in the clutch) on a early model V7. The fix was ... wait for it ... adjust the exhaust valve clearances to spec. So, Kaptain Holister hasn't done this yet (said so in a previous post) and is still experiencing this problem. You talk about hot exhaust headers. Symptoms are strangely pointing in a particular direction. Have you checked and adjusted valve clearances at all on your trike?

Holister · 82 Re: Engine cutout on throttle off Sat Sep 13, 2014 4:51 am

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robmack wrote:Very peculiar thing, but today I was reading posts on the Wildgoose site (dedicated Moto Guzzi forum) and came across an older post which spoke of exactly this problem (engine dying when pulling in the clutch) on a early model V7. The fix was ... wait for it ... adjust the exhaust valve clearances to spec. So, Kaptain Holister hasn't done this yet (said so in a previous post) and is still experiencing this problem. You talk about hot exhaust headers. Symptoms are strangely pointing in a particular direction. Have you checked and adjusted valve clearances at all on your trike?

Correct. valve clearances not checked. I just had a look at the very scant service records and as far as I can make out the last time that was checked was at 105k (one shim replaced). I bought it at 125k. It's now has 133k.
What's the service interval for this? Looks like it may be well over due.

Interestingly my brother bought the very first V7 Special sold in Australia back in 1974(?). At that time I was riding an R75/5

While I'm hoping this is indeed the fix, I'm baffled as to where the connection is. Did the Wildgoose poster elaborate in any way. If you could post the link, that would be great.

Thanks robmack

Hi wizzard
you can see the power of this forum is at work.
Hope we find a solution for your problem out of this also.

Cheers

Holister · 83 Re: Engine cutout on throttle off Sat Sep 13, 2014 5:01 am

Holister

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robmack wrote:The fix was ... wait for it ... adjust the exhaust valve clearances to spec.

would this also explain a persistant backfire on throttle off??
I've replaced exhaust gaskets, vent tube and tightened pipe>muffler flange bolts. Nowhere near as bad these days but I ride every day and at least a couple of times a week I get a loud pop (used to sound like a gun shot). Is there a connection here do you think?

robmack · 84 Re: Engine cutout on throttle off Sat Sep 13, 2014 9:49 am

robmack

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Number of posts : 2326

Kaptain Holister wrote:Did the Wildgoose poster elaborate in any way. If you could post the link, that would be great.

Brand new V7 Classic stalling

wizzard · 85 Red herring Sat Sep 13, 2014 4:45 pm

wizzard

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Number of posts : 16

I think that the clutch issue is a red herring - its just that going into a situation where you are braking and clutching at the same time you are usually not blipping the throttle at the same time as changing down.
I looked at the TPS connector block today and noticed one of the female connectors has got a couple of leafs missing so the signal may not be getting transferred to the ECU consistently. I tried putting in some tinfoil as a temporary fix but it made no difference. I need to do a continuity check on the wires between the TPS and the ECU, as the symptoms indicate a TPS malfunction.
Wizzard

Holister · 86 Re: Engine cutout on throttle off Sat Sep 13, 2014 9:13 pm

Holister

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Number of posts : 2491

I hear what your saying. Robmack has suggested that the clutch is a red herring. My feeling is that while its not the fault, its creating a state where the ECU is making a wrong decision about fuel/ignition. When the clutch switch opens (clutch lever in) it exposes the ECU to other parts of the circuitry. This why I was thinking the diode in the instruments because that's linked to the clutch sw. but I've tested it and its good.

I've tested my TPS completely and I'm satisfied its working as it should. That doesn't mean your is the same. Test your TPS.
PIN 1 - The middle pin is the common.
PIN 2 - Throttle closed switch. Normally open when throttle off ie continuity.
PIN 3 - Throttle open switch. Normally closed when throttle off. ie no continuity.

Meter between P1 & P 2 should read continuity (0 ohms) with throttle off. Open the throttle and it should immediately read no continuity (infinite ohms). The switch should cut in just as the throttle starts to move.

Meter between P1 & P3 should read no continuity (infinite ohms) with throttle off. Open the throttle fully and it should read continuity (0 ohms) just before you get to WOT.

Testing the connections between the TPS and ECU is a good idea. This is something I've not done. Been busy and just not got around to it. There is a post or download somewhere here that goes thru the process of checking 'pinout' & continuity from the ECU connector plug.

I've started recording pinouts of various connectors (including the ECU) as I've been working on my electrics. Don't know if this has been done before. Just helps when testing circuits.

I've organised to meetup with a K-member down in Newcastle next weekend to swap out the ECU and will post the results straight away but I'm not hopeful as you have said you have changed your ECU with no effect.
I think we'll find its something strange like a temp sensor or MAF or the thermistor and we'll all go "WTF" Shocked

Cheers Wiz

wizzard · 87 New ECU Tue Sep 16, 2014 3:06 pm

wizzard

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Number of posts : 16

How did it go with the new ECU ? Did that solve the problem? Mine is now losing power on full throttle situations (occasionaly) - it feels like it is running out of fuel. Then it goes shooting off again a nothing had ever happened. I've now ordered another fuel pump as (high pressure) as the original was looking a bit worse for the wear. The records say that the pump was changed a few years ago, but then the old one refitted for some reason, so it could be ancient.
Wizzard

Be made · 88 Re: Engine cutout on throttle off Thu Sep 18, 2014 5:22 am

Be made

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Number of posts : 666

Well . . . I have attempted to replicate the problem but to no avail. All mine does is dip below idle for a split second and then returns to normal idle revs.. without looking at your machine I would check the idle revs when engine is hot, check the throttle body syncro and the correck adjustment of the choke and clutch cables for a start point. sorry if I have rehashed what you might already have done.
Hope this post helps (somehow . . . . ) study

wizzard · 89 Throttle bodies Thu Sep 18, 2014 2:48 pm

wizzard

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Number of posts : 16

Thanks for the suggestions - I've tried them all except the throttle body syncro. That's on my list of things to do in the next week or so.
Wizzard

Holister · 90 Re: Engine cutout on throttle off Fri Sep 19, 2014 11:34 am

Holister

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Number of posts : 2491

wizzard wrote:How did it go with the new ECU ? Did that solve the problem?

Will be catching up with a couple of the guys in Newcastle this weekend to swap ECU and check valve clearances.
I've checked ECU plug wiring and all looks good there.

Problem has now become worse. Engine will not restart in gear with clutch engaged. Have to stop and get it into neutral to restart. This is going to be a problem for me if I get caught in heavy traffic. I'm hoping that's just a fault with the clutch switch but haven't had a chance to take a look as at the moment I'm on the road (till first week in Oct). Will get a chance this weekend hopefully.

Tripped from Lennox Head to Newcastle (600klm) earlier this week. Bike performed flawlessly.

Cheers

Tom G · 91 Engine cutout on throttle off Sat Sep 20, 2014 4:38 am

Tom G

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Number of posts : 639

G'day All, Kaptain Holister and GroverK called in today to try solve this problem. We swapped ECU and bingo all went well. This was done before Grover arrived. All in all it was a great afternoon with the Kaptain happy with the problem having been solved. Cheers Tom:P

Holister · 92 Re: Engine cutout on throttle off Sun Sep 21, 2014 5:12 am

Holister

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Number of posts : 2491

Well, I have to say, that was great to not only track down this annoying problem but also to meet-up with Tom and GroverK in Newcastle yesterday.
We swapped out the ECU from Tom's project bike (which I'm going to hang on to till I find a replacement... thanks mate Very Happy

) and took my old girl for a test ride (a fang) up and down Tom's local main road a few times. 5k in top gear in a 70kph zone... lucky the fuzz were not about Shocked

. Could not get the engine to cut out... YAAAYYY
Big thumb

The other recent issue with the start not working in gear with clutch in was merely a disconnected connector under the tank. Must have accidentally dislodged that the other day while prepping for my trip.

A big thanks to Tom and Ed for their assistance and friendship on Saturday. It was great to meet a couple of members and I can now say i have a couple of new mates. And a BIG thank you to Tom and Ann for their hospitality.
Cheers guys

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blaKey · 93 Re: Engine cutout on throttle off Sun Sep 21, 2014 5:28 am

blaKey

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This is what this forum is all about!

Good work guys!

Ed · 94 Re: Engine cutout on throttle off Sun Sep 21, 2014 5:35 am

Ed

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Number of posts : 2237

Nigel , glad you had it all sorted early in the day. Tom was very happy to have hosted the workshop day to get you going again.
hopefully on your next return , there will be a few more new faces for you to meet. and the chance of one of our local rides.
as mentioned at Tom's , you'll receive a top reception during your Sydney stay . ride safe and enjoy.

Nigel was a bit lost on the neccessity of the earth strap to the left lower edge of the fuel tank, I recommended he reinstall it until further notice. Any suggestions ?
he has the ex - police model.

Rick G · 95 Re: Engine cutout on throttle off Sun Sep 21, 2014 6:54 am

Rick G

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Number of posts : 12027

From what I have found out the earth strap was used to prevent radio frequency interference on the police 2 ways. I am not sure from where the RF was introduced but the fuel pump would be my guess. AFAIK it can be left off without causing any problems.

Inge K. · 96 Re: Engine cutout on throttle off Sun Sep 21, 2014 9:55 am

Inge K.

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RicK G wrote:From what I have found out .

I would guess that you did find out about the earth strap at post #22 in this thread.

Holister · 97 Re: Engine cutout on throttle off Sun Sep 21, 2014 10:25 am

Holister

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Number of posts : 2491

Re: tank earth strap.
My querie came from the fact that I couldn't find any reference to it in the Haynes manual or any other documentation. With the lower fairings off the earth strip can be easily seen.
I removed the lower fairings to be able to make repairs to the mounting points on the top fairing and work on the engine and then decided to leave them off for my trip south. I'm liking to look and feel of the bike with her skirt off and can hardly wait to get her totally naked Twisted Evil

One big positive from traking this problem down is that I've learnt a lot about this engine and her electrics and feel a little more in tune with her workings.

Also, I forgot to mention, a big thank you to everyone who participated and contributed to this thread.

Cheers everyone.

charlie99 · 98 Re: Engine cutout on throttle off Sun Sep 21, 2014 12:13 pm

charlie99

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Number of posts : 11685

yay !!

mike d · 99 Re: Engine cutout on throttle off Sun Sep 21, 2014 1:58 pm

mike d

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Number of posts : 609

Good to here the replacement ECU appears to have provided a cure.

Any chance of the 'suspect' ECU being installed on another bike to see if the fault is still evident?

Mike

charlie99 · **100** Re: Engine cutout on throttle off Sun Sep 21, 2014 2:49 pm

charlie99

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Number of posts : 11685

good point mike

makes sense to me to prove the fault .

mike d · **101** Re: Engine cutout on throttle off Sun Sep 21, 2014 3:45 pm

mike d

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Number of posts : 609

Given that I hold the BMW Special tools for the BMW Club UK, in the past I have though of getting hold of 'standy' parts, like ECUs, to send out to our Club Members who may be in a similar position as the Kaptain. The only drawback would be where a bike fault fries the ECU. If that occurred, my 'loaner' would be short lived. Crying or Very sad

Only yesterday I stripped and rebuilt a rear drive from a 1200GS (Main bearing failure) for a club member. Today, at a Club meeting, I discussed the option of having a standby (rebuilt) unit, that could get someone back on the road promptly, allowing them to sort out their own drive in a more leisurely timeframe.

I may look at this in more detail.

P.S. 2 x bearings, 2 x oil seals. 1 x casing 'O' ring 10 x casing bolts and three crush washers was just over £130

Mike

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