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1Back to top Go down    Fuel pump not running 87 k100 on Fri Dec 14, 2018 6:07 pm

yankeeone

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Hi, it has been awhile since I had a problem with the bike, this one has me stumped. 

History. A few months ago I went to start the bike and had to crank longer than I ever had to. Stopped and regrouped, at that point I realized the pump wasn't running, not at the press of the starter button or when cranking.
I tested the pump,the connectors both before the tank and at the tank, all had continuity. By some magic the pump ran and continued to run.
I went start last night (bike has sat for three weeks or so) same thing, no pump, this time wiggle the wires at the disconnect and pump runs. 
Try again today nothing will make it run. I tear into it, cut out the connector, put 12 volts to the green /white wire pump runs. Ok check continuity for that wire to the temp relay, all good. Clean the connectors on the black fuel pump relay , no change, I hooked a 12 volt light on the pump wire(green white) so I will know if I get juice when I hit starter button.

 Questions. If the starter button will connect to spin the starter does that mean it is sending juice to pump relay, or is there something to check at that end?
 I have switched relays and no change, I guess it is down to temp sensor, I have a extra temp sensor I could switch with, can I just hook up the spare sensor off the motor and ground it to the block?
Thanks 
Brian

    

2Back to top Go down    Re: Fuel pump not running 87 k100 on Sat Dec 15, 2018 3:27 am

Laitch

Laitch
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@yankeeone wrote: If the starter button will connect to spin the starter does that mean it is sending juice to pump relay, or is there something to check at that end?
I have switched relays and no change, I guess it is down to temp sensor . . .
There is always more to check. Smile

When the starter button is pushed and the starter is spinning, the fuel injection relay contacts should close. Current then passes through a red/green wire at the relay to fuse #6 then to the green/white wire which feeds the fuel pump motor via the fuel level sender in the tank. The wiring between the sender and the pump inside the tank should be checked if it hasn't been already. You already seem prepared to check for 12V in the green/white wire when the starter button is pushed.

After the starter button is released and the engine is running, signals from the Hall Effect sensors to the ignition control unit keep the fuel injection relay contacts closed so the pump continues running. If the engine doesn't start up—or the Hall sensors/connections are defective—no signal will be sent to the ignition control unit; consequently, the fuel injection relay contacts will open when the starter button is released, and the pump will shut down. The sound of the pump shutting down will usually be heard.

The temperature sensing switch receives current to manage the fan and temperature warning light; it doesn't send current to the fuel pump.


__________________________________________________
1995 K75T 68,000 miles
    

3Back to top Go down    Re: Fuel pump not running 87 k100 on Sat Dec 15, 2018 4:57 am

yankeeone

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Thanks,
Fuse six? six down from the top?
The book says the injection relay is the top right,if I close the contacts with relay in and cover off the horn goes off. wrong relay?(made me jump)
The tank is off, could I test the fuel level sender with continuity test?
When I first took off tank and cut out the connector,I hooked up 12 volt light to the green/white and ground, and for five or six times Ii got the light to go when I pushed the starter button, then I went out when I let off. So it worked correctly. Then it failed again.
I took off all the grounds and cleaned them no change.
 I am going to check the big connector plugs for the right handlebar switch this morning.

    

4Back to top Go down    Re: Fuel pump not running 87 k100 on Sat Dec 15, 2018 5:10 am

Point-Seven-five

Point-Seven-five
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The first half of your tale of woe makes me think you had the infamous tank connector act up with an intermittent connection that finally crapped out.  I can't understand exactly what you did after you cut the connector out and bypassed it.  I suspect that your attempt to fix your problem by rewiring has messed up the wiring for the pump.

I would suggest going back and double checking what you did after you removed the tank connector.  Beyond your attempts at a rewiring repair I don't really think you have a problem.


__________________________________________________
Present:
1994 K75RT
1991 K100RS

Past:
1994 BMW K75S
1992 BMW K100RS
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

5Back to top Go down    Re: Fuel pump not running 87 k100 on Sat Dec 15, 2018 5:30 am

yankeeone

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Point seven five,
Thanks, 
Basically all I have done is unplug and remove tank, so I have the wire green/white that powers the pump available to test before the connector, if the wire is not being feed at that point it does not get to the connector on the tank.I did test those the first time the problem came up.

    

6Back to top Go down    Re: Fuel pump not running 87 k100 on Sat Dec 15, 2018 5:51 am

Laitch

Laitch
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@yankeeone wrote:Fuse six? six down from the top?
There's no reason for us to go staggering hungrily through the wilderness when there are references  to be found along our path, like low hanging fruit—unless we've encountered one too many mimosas or wild turkeys along the way.

Regardless, this one is from the K100 Rider's Manual. A copy of the Rider's Manual is available in the forum's Tech Page.

Fuse 6 and also 1, 2, 3, 4, 5, and 7

Clean the plugs of the ignition control unit and the fuel injection control unit with DeoxIT contact cleaner and review your previous work as .75 suggests. At the root of this is probably a "So that's all there is to it?"


__________________________________________________
1995 K75T 68,000 miles
    

7Back to top Go down    Re: Fuel pump not running 87 k100 on Sat Dec 15, 2018 6:37 am

Point-Seven-five

Point-Seven-five
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@yankeeone wrote:History. A few months ago I went to start the bike and had to crank longer than I ever had to. Stopped and regrouped, at that point I realized the pump wasn't running, not at the press of the starter button or when cranking.
I tested the pump,the connectors both before the tank and at the tank, all had continuity. By some magic the pump ran and continued to run.

Typical tank connector problem. 

I went start last night (bike has sat for three weeks or so) same thing, no pump, this time wiggle the wires at the disconnect and pump runs. 

Typical tank connector problem.  Again.

Try again today nothing will make it run. I tear into it, cut out the connector, put 12 volts to the green /white wire pump runs.

Pump is good, tank connector is whack.

Ok check continuity for that wire to the temp relay, all good.

Continuity to red/green wire on fuel injection/pump relay???  That's where the power for the pump comes from.

Clean the connectors on the black fuel pump relay , no change, I hooked a 12 volt light on the pump wire(green white) so I will know if I get juice when I hit starter button.

Sounds good. 

Questions. If the starter button will connect to spin the starter does that mean it is sending juice to pump relay, or is there something to check at that end?

The pump relay gets energized by the ECU.  The pump relay coil gets power from fuse#1 through a green/yellow wire and is grounded through the yellow/brown wire at pin #7 on the ECU.  The green/yellow wire on the pump relay should have 12V when the ignition is turned on.  The red wire on the pump relay should have 12V all the time.  The start button has nothing to do with the pump relay.  If the starter runs, the button is working.

 I have switched relays and no change,

What relays did you swap?  Put them back where they came from.  You could be introducing new problems.

I guess it is down to temp sensor, I have a extra temp sensor I could switch with, can I just hook up the spare sensor off the motor and ground it to the block?

It's NOT the temperature switch.  Ignore it.



Last edited by Point-Seven-five on Sat Dec 15, 2018 6:48 am; edited 1 time in total


__________________________________________________
Present:
1994 K75RT
1991 K100RS

Past:
1994 BMW K75S
1992 BMW K100RS
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

8Back to top Go down    Re: Fuel pump not running 87 k100 on Sat Dec 15, 2018 6:45 am

yamaguzzi

yamaguzzi
Silver member
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Oh,this sounds familiar . One thing I have learned about these bikes is that almost every problem with the bike not starting or missing or running poorly is related to bad connections. This is assuming that the bike is in overall good condition to start with like mine was and still is.Corrosion,lose wires,bad fuses are what I have had to address and each time it solved the problem so go thru the bike and clean all your connections  , put dilectric grease on them , give it all new fuses and clean the receiving  end where they plug in.tighten everything up and see what happens.


__________________________________________________
1988 K 100RS ,1975 Moto Guzzi 850-T , 1971 BMW R60/5 , 1971 Yamaha R5B,1969 Yamaha DS6C ,1966 Yamaha YM1 , 1965 Yamaha YDS3
https://motoguzzi850t.blogspot.com/
    

9Back to top Go down    Re: Fuel pump not running 87 k100 on Sat Dec 15, 2018 4:51 pm

yankeeone

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Bike is running, pump may be suspect, I bought it new ten years ago for a K75 and when I parted it out put the pump in k100. Ten years goes fast. If it happens again I am going to bypass all and check with power right to pump.
The first time it happened I checked  the tank connector, took out the fuel level sending unit tested all for continuity three times, wiggled pulled prodded, never lost continuity. I feel pretty confident that is not the problem. 
While I have the tank off I will go through connections with cleaner.
I haven't had a drink in twenty years, so I cant blame that.

Yamaguzzi, 

Thanks, as I was checking things I was thinking "this baby is getting old" she has a 100 thou on it, and the years are taking a toll on the rubber bits.
engine is still sweet, can balance a nickle on edge on the gas cap while the bike is running. a few years ago I put the updated twelve rivet output shaft in so no slop in the drive train.

    

10Back to top Go down    Re: Fuel pump not running 87 k100 on Sun Dec 16, 2018 6:17 am

Point-Seven-five

Point-Seven-five
Life time member
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So what finally got it running?  Did you replace the fuel pump?


__________________________________________________
Present:
1994 K75RT
1991 K100RS

Past:
1994 BMW K75S
1992 BMW K100RS
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

11Back to top Go down    Re: Fuel pump not running 87 k100 on Sun Dec 16, 2018 3:41 pm

yankeeone

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When the pump started to run after many pushes of the button it sounded slow at first then picked up,so I am thinking it may locking up when it sits to long.

    

12Back to top Go down    Re: Fuel pump not running 87 k100 on Mon Dec 17, 2018 1:57 pm

Arlina

Arlina
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Sounds like crap in your pump.
Had some similar, took pump out, emptied it from fuel, hooked it to my battery, but - to + and + to -, so it ran backwards.
Switched some times forward/backwards, and life came back to the pump. And some crap came out.
Flushed the pump, runs for 30000km since then.


edit; take a new fuelfilter, and check for crap in the tank Smile


__________________________________________________
  K1100RS/LT - R1200RT - K100LT 16v - R1100RS (RIP) - Cagiva SST 350 Ala Verde 
    

13Back to top Go down    Re: Fuel pump not running 87 k100 on Mon Dec 17, 2018 6:05 pm

duck

duck
Life time member
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If it's crap in the fuel pump causing issues it is possible to disassemble to fuel pump to clean it out.


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT (x2)
91 K1
93 K75S (K11 front end)
91 K75S (K1 front end)
14 Yamaha WR250R
http://www.ClassicKBikes.com
    

14Back to top Go down    Re: Fuel pump not running 87 k100 on Tue Dec 18, 2018 12:05 am

92KK 84WW Olaf

92KK 84WW Olaf
Life time member
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We can get pumps over here for about £45 so I have never thought of disassembling one. Same pump was fitted to a lot of European cars and readily available.


__________________________________________________
1992 K100LT 0193214 Bertha Alaska Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 58,645 now 90,575 miles
1983 K100RS 0011175 Fricka 29,000 miles Damn K Pox
    

15Back to top Go down    Re: Fuel pump not running 87 k100 on Tue Dec 18, 2018 3:30 pm

yamaguzzi

yamaguzzi
Silver member
Silver member


__________________________________________________
1988 K 100RS ,1975 Moto Guzzi 850-T , 1971 BMW R60/5 , 1971 Yamaha R5B,1969 Yamaha DS6C ,1966 Yamaha YM1 , 1965 Yamaha YDS3
https://motoguzzi850t.blogspot.com/
    

16Back to top Go down    Re: Fuel pump not running 87 k100 on Tue Dec 18, 2018 3:46 pm

brickrider2

brickrider2
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Nice gesture Yammaguzzi, but that link leads to "not available."


__________________________________________________
1996 K1100LT
    

17Back to top Go down    Re: Fuel pump not running 87 k100 on Tue Dec 18, 2018 4:01 pm

yamaguzzi

yamaguzzi
Silver member
Silver member
But that doesn't mean it's not available it just means it's not available thru this particular vendor . The part is readily available it's used in millions of late model Ford vehicles
Here is one https://www.autopartswarehouse.com/engine-and-drivetrain/fuel-systems-and-components/fuel-pump/airtex/afe2001
I would only use something like this if I was out on a trip and needed to fix my bike to continue.But, it's good knowing that when you travel you can substitute stuff like this dirt cheap 40 dollar fuel pump in place of a 250 dollar aftermarket one for the bike or a 500 dollar genuine BMW one and continue on your way. How long will it last? Who knows but it will get you home.



Last edited by yamaguzzi on Tue Dec 18, 2018 4:29 pm; edited 1 time in total


__________________________________________________
1988 K 100RS ,1975 Moto Guzzi 850-T , 1971 BMW R60/5 , 1971 Yamaha R5B,1969 Yamaha DS6C ,1966 Yamaha YM1 , 1965 Yamaha YDS3
https://motoguzzi850t.blogspot.com/
    

18Back to top Go down    Re: Fuel pump not running 87 k100 on Tue Dec 18, 2018 4:24 pm

yankeeone

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Gold member
Thanks All, if the pump fails to run again, and fails to run when connected directly from 12 volts, I will buy this pump and hopefully be good for ten more years.


  https://www.highflowfuel.com/i-35462336-quantum-intank-efi-fuel-pump-for-bmw-k100-1984-1992-replaces-16121461576.html?ref=category:335661

    

19Back to top Go down    Re: Fuel pump not running 87 k100 on Tue Jan 01, 2019 8:18 am

glennpm

glennpm
Silver member
Silver member
Hi,

I just through a whole myriad of checks last Spring and found my fuel pump was bad. The piss in the bucket wouldn't have told me there was a problem. The bad pump was not putting out enough pressure but you're beyond that point now! This is the pump I put in:

Pump specs:

Facet-Purolator FEP2042 In-Tank Fuel Pump, 1991-1993 Ford
Escort, 1986-1995 Ford Taurus, 1988-1994 Lincoln Continental, 1986-1995
Mercury Sable, 1991-1993 Mercury Tracer

http://www.motobrick.com/index.php?topic=7066.0

http://www.motobrick.com/index.php?topic=2058.0

http://www.k100-forum.com/t2019-fuel-pump-replacement

I bought a new damper and used fuel cell foam between the smaller diameter replacement and the original can. The article attached shows this detail.

Glenn


http://forum.kforum-tech.com/members-upload/uploads/K_75_100_Fuel_Pump(1).pdf

    

20Back to top Go down    Re: Fuel pump not running 87 k100 on Tue Jan 01, 2019 1:23 pm

duck

duck
Life time member
Life time member
If you use one of those pumps be sure to mount it as low as possible in the tank and be careful about running too low on fuel. I installed one in a K75 and if running low the fuel pump would get starved and kill the bike on right hand turns and then take several minutes sitting on the side of the road until the pump would reprime itself.


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT (x2)
91 K1
93 K75S (K11 front end)
91 K75S (K1 front end)
14 Yamaha WR250R
http://www.ClassicKBikes.com
    

21Back to top Go down    Re: Fuel pump not running 87 k100 on Tue Jan 01, 2019 2:53 pm

glennpm

glennpm
Silver member
Silver member
Thanks for the warning Duck. Did you end up changing to a stock pump?

Glenn

    

22Back to top Go down    Re: Fuel pump not running 87 k100 on Tue Jan 01, 2019 3:15 pm

duck

duck
Life time member
Life time member
@glennpm wrote:Thanks for the warning Duck. Did you end up changing to a stock pump?

Glenn
No. I sold the bike. Very Happy

But if I'd kept it I probably just would've been more careful about keeping enough fuel in it since the pump worked fine other than that.


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT (x2)
91 K1
93 K75S (K11 front end)
91 K75S (K1 front end)
14 Yamaha WR250R
http://www.ClassicKBikes.com
    

23Back to top Go down    Re: Fuel pump not running 87 k100 on Tue Jan 01, 2019 4:00 pm

Laitch

Laitch
Life time member
Life time member
@duck wrote:If you use one of those pumps be sure to mount it as low as possible in the tank and be careful about running too low on fuel. I installed one in a K75 and if running low the fuel pump would get starved and kill the bike on right hand turns and then take several minutes sitting on the side of the road until the pump would reprime itself.
This modification might help mitigate that problem.


__________________________________________________
1995 K75T 68,000 miles
    

24Back to top Go down    Re: Fuel pump not running 87 k100 on Tue Jan 01, 2019 5:00 pm

glennpm

glennpm
Silver member
Silver member
Great, thanks Laitch!

First time I've seen this bulletin so it now safely saved on my computer ;-)

Glenn

    

25Back to top Go down    Re: Fuel pump not running 87 k100 on Tue Jan 01, 2019 5:20 pm

duck

duck
Life time member
Life time member
Interesting TSB.

It took BMW until 1994 to figure that out? lol!


__________________________________________________
Current stable:
86 Custom K100 (standard fairing, K75 Belly pan, Ceramic chromed engine covers, paralever)
K75 Frankenbrick (Paralever, K11 front end, hybrid ABS, K1100RS fairing, radial tires)
86 K75C Turbo w/ paralever
94 K1100RS
93 K1100LT (x2)
91 K1
93 K75S (K11 front end)
91 K75S (K1 front end)
14 Yamaha WR250R
http://www.ClassicKBikes.com
    

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