Hi guys,

I've got a '86 K100 (I have made an intro thread) and am going to embark on a crusade today to get it to start. I'd like some guidance on a couple of points. (Questions at bottom if this is too long to read)
I have read the troubleshooting guides and also found the online manual, which I've downloaded. This is my first fuel injection bike too.

I got the bike from a guy who said it was working, but it had a 17Ah battery in it, which didn't seem to be the right one from online resources. I bought a 30Ah and it fits in the tray and the bike cranks easily.

When I turn the key, there is a muffled click or clunk from in the tank somewhere, but thats all. The tank was full of old fuel, so I siphoned that out. The tank is in reasonable shape, but here is a photo or two so you can tell me if I'm right about the condition. The fuel float is pretty rusty, however.




I put new fuel in, but there isn't any difference in starting. My plan is to siphon out the good fuel, take the tank off and do the electrical troubleshooting underneath. While this is happening, clean the tank out with a pressure cleaner, rinse with metho and then blowdry to clean and dry fully.

I also noticed that we have possibly some issues here:


The rightmost body seems to have a weeping issue. 

I've checked fuses with a mulitmeter and they are fine.

Questions:
Does the tank look to be in good shape?
Any idea what could be wrong with the pump not starting?
What noise should the pump actually make?
Can the tank come off without having to be emptied?
Is bleeding the brakes similar in straightforwardness to other 80's machines?

Thankyou for your assistance, and I look forward to perusing the rest of the forums.

Welcome to the madhouse .

The clunK you hear from the tank, I'll guess is from a seized fuel pump.
The fuel pump should run for ~1,5 sec when you hit the starter button.
Try to reverse the pump for a few seconds, smallest terminal is +.

You're missing a rubber cap at #3 throttle body.
Check the crank vent hose, S shaped at the rear end of the plenum chamber,
it have a rather short average lifetime.

The vent hose for the pump prefilter is torn into two pieces, but shouldn't
make much problem.....but get a submersible one when changing it.

So after a bit of work, I've discovered a few things.

Under tank doesn't look too bad, as far as I know.


The fuel pump is dead. No noise or movement and the basket/filter thing it sits in had practically disintegrated. This is the pump



I've found a few sites overseas that sell the pumps, but there are a couple here from local sellers. Would they be suitable, going on listed specs? Also, what bits do I need for the full replacement? There is talk of foam and other things and I'm not sure what is required.

http://www.ebay.com.au/itm/Universal-Inline-Fuel-Pump-BMW-Holden-Citroen-Peugeot-Reference-0580464070-/321295015475?pt=AU_Car_Parts_Accessories&hash=item4aceacde33

http://www.ebay.com.au/itm/High-flow-motorsport-Fuel-pump-DDRacing-070-/171004669859?pt=AU_Car_Parts_Accessories&hash=item27d0ac2fa3

Otherwise, its the more expensive option
http://www.euromotoelectrics.com/EnDuraLast-BMW-K-52mm-Fuel-Pump-16-12-14-61-576-p/fp-576edl.htm

The tank was filled with a mix of rusted flakes and dead rubber bits. This is after a flush with water and metho!




I'll need a new fuel float thing/assembly as its frozen with rust. The float was wrapped in plastic...


Other than the general neglect, I think this is all quite promising. I love the aluminum fuel tank, so ligt and easy to slosh around!

If anyone can assist, I'll be very grateful for words of wisdom.

Don't give up on that fuel sender unit.  Give it a soak in white vinegar or lemon juice for a few days and see if things can be made to move again.

Yeah, I came across this link which has been very helpful. Might have some hope for it after all.

http://hrsbstaff.ednet.ns.ca/bvogel/K100/download/electrical/fuel%20sensors/fuel%20level%20sensors.htm

The VL commodore pump is a direct replacement and works well. You probably need the rubber vibration damper and EME is a good source along with Motobins in UK. I have used a pump from an EB Falcon sedan and it works well but is smaller in diameter but I used big zip ties and made the damper fit it.
A dirty tank I have used the bluemetal (crushed basalt) in the tank with some water and dish detergent to clean it by sloshing and shaking it cleans very well and is big enough to be able to get all of it out easily.

VL commie pump sounds like the way to go. If they say external, does this mean I can't use them?

Don't use an external pump. The VL pump is almost identical except for thr connectors I think it has push on spade type

There is a 52mm pump on ebay I've referred to and it says its an inline pump suitable for a bunch of BMWs and VL commodores.

I've contacted the seller to see if its an in-tank use application.

Edit: Turns out it's external, and I can't seem to find local internal ones. Might just have to go with an overseas job

I saw that one, but it says it's external in the fine print.

This should be the right pump http://www.ebay.com.au/itm/EFI-FUEL-PUMP-REPLACES-BOSCH-0580464070-VL-COMMODORE-3-0L-TURBO-NON-TURBO-/121050762243?pt=AU_Car_Parts_Accessories&hash=item1c2f300c03
I pity the poor bugger that tries to run that other one externally as it WILL overheat and cook.
use the filter that comes with the pump, you may need to double the filter over and zip tie it to make installation easier and don't be concerned about it saying 3 bar, the pressure regulator will do its job.

OK, so after much ado, I have a new pump and filter and have cleaned out the tank, hooked everything back up and put it all back on the bike with 10 liters of fresh fuel.

So I went to start it, and I hit the starter. It cranks but doesn't fire. This time however, there is a distinct noise coming from the tank (like a whirring buzz) so at least the fule pump is working, supposedly.

The only thing that I did not actually hook up was the hose that goes from the filter basket back up to the vent at the top. The original was hard and broke off, and I couldn't find a replacement. Is this something fairly critical?

Any information would be helpful as I feel I'm very close to getting it going! 

Hessian wrote:The only thing that I did not actually hook up was the hose that goes from the filter basket back up to the vent at the top. The original was hard and broke off, and I couldn't find a replacement. Is this something fairly critical?

The hose is there to avoid cavitation in the pump, the bike will function w/o it.
But to avoid that the small tiny creatures living in your tank being sucked into
this big black hole, you must have a new one which must be submersible,
some also have just blocked this hole w/o any problems.

If the bike will run without the hose, what else can I try to get it started?

First will be to take a look at the plugs to see if it gets fuel and a spark is present.

Ok, so update.

Sparkplugs had spark, a little dirty however, so I thought id get some new ones. The new ones spark quite well.

Unplugged the fuel line, hit the starter and a lot of fuel comes out, so the pump is working. Could it be the injectors?

I'm holding in clutch, sidestand up and hitting starter. Get the oil light and battery light turn on initially. Also hazard light appears in the centre of the dash. Bike is in neutral. Have tried using the throttle, choke and its only coughed once.

The injectors could well need a clean. Remove them and connect 12v to then only very momentarily  or you can damage the coils, if they click they probably can be cleaned easily. I use a 9v smoke detector battery to operate then so as not to damage then and when open squirt some carby and throttle cleaner through them and remove the battery and let them sit for half an hour, do the same again and then remove the tiny prefilter in the inlet and clean them up put a new filter and O-rings and try them in the bike or onto a piece of dark cardboard to check the spray pattern. You should get a fine mist which will show as a circular spray after a few sprays
You can but filter and O-rings on fleabay. Don't buy genuine unless you own a bank or have just robbed one.

You can also buy an injector kit (filter, o-rings x2, spacer and pintle cap) from Repco for about $14 - Fuelmiser part# ISK-0500AX contains 2 sets.
There's lots of stuff on Youtube about how to clean injectors as Rick explained and also how to get the filters out and replace everything. Also while they're out check the impedance. They should measure 16.2 ohms or very close to it.
You'll probably find someone locally who can clean and refurbish for around $30 each.

Very important to clean really well around the injector recesses before you remove them to prevent accumulated dirt getting into your head.

See if you are getting a pulse at the injectors. The trouble shooting guide gives details of how to make a tester.



I keep this one in my tooltray....just in case.
Paul.

I'm going to have to ghetto one of those testers up. I won't be able to make one today, but I found something useful and I want to check I'm on the right track.

I read the troubleshooting guide that is lying around the net, and one section suggests testing the plug of the EFI unit/computer.

This section below was of interest:

12	Ground to injectors	Between pin #12 and pin #9	Ω	1 injector 16Ω
			Ω	2 injectors 8Ω
			Ω	3 injectors 5.33Ω
			Ω	4 injectors 4Ω

I did as was told and my Ohms turned out to be 5.5 Does this mean I have 3 working injectors, or that three are not getting power?

The guide is here: http://hrsbstaff.ednet.ns.ca/bvogel/K100/download/bike-wont-start1.htm

You are the measuring the resistance through the coils in parallell.
You should have ended up with 5,3 ohms as one coil is 16 ohm.
But this sounds close enough....

Sorry, but what does the reading mean? Is something broken?

The reading says that your injector coils is OK.

Ah ok. Thats good

So there is fuel, there is spark, injectors are getting power. Not firing though. I cleaned the ground connectors.

Seems strange that none fire at all, so it must be junction where something is common

Do you get fuel into the cylinders? How does the plugs look, wet, dry?
You can use a screwdriver as a stetoscope and listen if the injectors clicks (opens).

The plugs were dry. One had a drop of oil on it. I'll try the screwdriver idea!

Another weekend, another round of fixes.

So I cleaned the connectors between the FI computer and plug, put the bike up onto the centre stand and tried to listen to the injectors firing. Anyway, I couldn't hear them specifically, but the bike was firing like it ALMOST would start.

Anyway, I figured I'd have a look at the injectors. Turns out each of them was covered in a paste of road grime and dirt, so I thought I'd take them off and get them serviced before putting them back on.

If dirt gets in the injector holes in the head of the engine, will that have some impact on the engine or will it just get burned?

you could use a screw driver tip up against the injector and place your ear on the handle ....stethoscope wise to get a listen ?

Yeah I tried the screwdriver thing. I put it on the top of the injector and I think I heard one click, but that was about it. The bike on the other hand was firing like it wanted to start, so I guess it may have eventually had enough fuel to spark from one or two injectors working intermittently. The firing seemed to come in periods and then stop, so it seems likely the injectors are clogged or whatever. I'm going to get someone local to service them

Clean in around the injectors as the dirt can do damage especially sand grains. Usually a blast of compressed air will clean it out before you take the injectors out.

Hessian, I have PM'd you.

Hi team,

I've managed to get some injectors from a forum member, but when I went to have a look, they appear to be different types. The forum member and I are discussing the problem, but I'd be interested to hear the levels of compatibility between the models.

Going from the compliance plate, I have a 8/86 K100RS. My injector is on the right.



Close up of numbers

Hessian, I've checked with photos from a couple of ebay sellers and these should be right for your bike.

I hope someone on here can confirm they are ok to use.

Neil.

If the part number is 0280150210, then it should work.

Well the number is the same, but does that mean the current injectors are somehow incorrect?

The numbers are on the injectors in the photo, but yeah its 028015021

The 705s are from a K1100 or a 16 valve

Yes, I enlarged the picture and read the number.  The 0280-150-210 injectors are OEM K75/K100


Your originals are 0280-150-705 which have slightly more flow.


source: http://www.witchhunter.com/injectordata1.php

The 705 is a good replacement for the 210
It uses the same operating pressure (2.5 bar) which is important and has only 1.5g/min greater flow than the 210.
The only other difference is the 210 coil inpeadance is 15.15 ohms. The 705 is 15.9 ohms.

EDIT: Just to avoid confusion and to confirm robmack's info...
3 bar is the test pressure and at that pressure my data says
210 - 160cc/min
705 - 164cc/min

All good

Thanks for all the responses guys.

But, FFS, even with some new injectors, the old beast is not firing. I'll have to go back to the drawing board and see where I can go from here

Probably electrical then.
BUT I noticed you've installed a new battery about a month or two back and have been cranking it over so don't forget to keep it charged up. Don't leave it on the charger for too long, even a trickle charger. Battery voltage across the terminals or positive terminal to earth should not drop below 12.5 V or you'll damage the plates. Leave it about 12 to 24 hours after a charge before measuring.
Cheers

Have you checked the ign timing and that the correct coils are connected to the correct cylinders. Its easy to do just ask me how easy.

Well I had a look at the firing and the coils seem to be hooked up correctly (1 and 4 / 2 and 3). Two of the plug caps had been a little loose on further inspection, but no difference in starting. Cranks but doesn't fire

Here's what we are working with


And the connections at the bottom of ze coils

Probably pay to check the timing at the Hall sensors, front of engine behind t shape cover should look like this

For reference 1mm is about 1° at the outer circumference of the plate.
Probably is OK but you just never know what previous owners do.

I bought a K100 that had been stood for years with fuel in the tank and it destroyed everything inside the tank.
Everything looked exactly like the pictures above and it was obvious it wasn't going to go.
We used a temporary external pump to go for a start but the bike wouldn't fire.
We clamped the fuel return pipe shut to create more pressure to the injectors and "Hey Presto" it went. It was a little rough until the injectors cycled for a while but they cleared and the bike ran OK.

Try it,it's worth a go.

Just another thought,have you changed all the pipework? The rubber damper is like black jelly that gets everywhere when it's melted but if it sets,it becomes quite hard and may have blocked something outside the tank.
Good luck.

So, just to understand where you are right now and what you've done so far:

• replace fuel pump
  
• new fuel filter
  
• cleaned tank
  
• Checked that fuel pump works and Tested pressure
  
• changed spark plugs
  
• new battery
  
• new injectors
  
• clean connector between FI and plug
  
• check coil wiring
  
• check spark wires
  

It seems you should have fuel to the cylinders, spark to the plugs and assuming that there the nothing wrong with the AFM, air to the throttle bodies. Have you checked and replaced the crankcase vent hose and rubber plug on the third TB vent tube (not that it is contributing to your inability to start the bike)?  Have you done the tests on the ignition computer as outlined in Bert's troubleshooting guide?  Have you checked the cam shaft clearances. Tight gaps can cause the bike to stall when running; they may prevent starting, I should think.

Ummm... What happens if the fuel pressure regulator is stuck open and just letting the fuel flow straight through the rail without any real pressure behind it?  Can it fail in that mode?

I assume that there is plenty of fuel flow at the end of the hose supplying the rail.

Unfortunately the weekend is the only real time I get to spend with the bikes. However, I tried clamping the return line and even after sitting on charge for 12 hours there is no difference. I'm thinking its an electrical problem. If I get the chance again this week, I'll re-check all the spark plugs for a start and browse the guide again to see if there are any glaring issues.

Also, if I pulled the fuel rail out and hit the starter, would that show the injectors working? Im more familiar with carbs, so sorry for the dumb question! Thankyou again for your assistance

Yes, it would. Have a large bucket to catch the fuel and fire extinguisher handy.