BMW R1200R R1150R/T F800 K1200R R1100R/T R1250R RnineT Message Board

PROBLEM: Fuel pump shuts off intermittently, or will not come on when starting the bike.

PROBLEM DETAIL: I know, the bike is a day old now, but the fuel shut off on me, twice. First time I didn't know how to fix it so it was towed back to the dealership, and my salesmen was visibly upset that the bike even had an issue. Well, at the dealership they took the cover off of the fuse panal then tapped the relay for the fuel pump, which is what I did in the field only I pushed it to make sure it was seated, I didn't tap it, either way tapping it got it going again. Well, it hapened again today only the bike was running when it happened, and again I tapped the relay and off it went; first time I couldn't get the bike to start after being shut down for about 20 minutes. I thought maybe there was a problem with the governer kicking in ( I *aasume* that when a govener kicks in it shuts down the fuel pump) , which I don't know why it would as I am keeping the bike under 4000RPM, and under 120 Km's/Hr. The second thing is that maybe the relay is just loose. But I just tried the relay by taking it part way out of its socket, and the pump still works, its only until I fully remove it that the pump quits. That fact that I had to hit it to get it to work, does that mean it is being reset, I mean is the relay also a circuit breaker? Or is is it not a relay at all and just a circuit breaker?? If it is a circuit breaker, that could mean a very serious issue with either the electrical system or the fuel pump, or any point between. Anybody have this issue, or know if there is a service recall on this??? I'll take it to the dealer oni Monday, I'm just trying to figure out how a brand new bike is having an issue.


UPDATE: the relay went again yesterday, and unless this image is wrong http://home.mindspring.com/~jabrooks/images/fuses.jpg , the relay that I hit to get the fuel pump to come back on was the Motronic relay. I emailed the dealer and their going to check it out and replace that relay just to be sure.


SOLUTION: It is definitely the relay. To troubleshoot this once and for all, I did the following:

If I tap the Motronic relay with the fusebox cover door a few times, the fuel pump cycles every few taps (fuel pump relay and motronic relay are connected in series), I then changed the fuel pump relay with the Motronic relay (that’s the relay I have identified as having a fault), then tapped the (Fuel Pump) relay that was now located in the Motronic relays slot, and it didn’t effect the fuel pump one bit. Tapped a few more times, still no effect. Then I put the suspect (Motronic) relay back in its native slot, tapped it, and the fuel pump comes on every few taps. Therefore it is not the connection to the relay ports, but (Motronic) relay itself. I have now swapped the Motronic relay for the horn relay as they both have the same part number.

I’m not too concerned as the bike goes in on Tuesday to get the 1000k service done.

Finally, I have this problem sorted.

Thanks to all that posted links and gave encouragement.


Hopefully if anyone else has this problem, my detaling the problem and solution, they will be able to solve the problem quickly and efficiently.

Didn't you know about this little problem...this's why we all carry a hammer under our seat.

Just kidding...after 5 yrs of following these forums and owning mine I've never heard of this.

I hope they get it all sorted for you soon.

What a bugger!

DJ

Oh dear, I was hoping this was a common problem with an easy do it yourself fix.

Dwayne,

There was once a story about a person who had fuel pump problems with his brand new KLT. He had a horrible experience with BMW repeatedly not being able to find the real problem. They eventually tracked it down to a bad relay. I think they referigerated the relay overnight, installed it, started the bike, then put a heat gun on it. Once the relay warmed to a certain temperature, it woud just quit working.

It would be a pretty cheap swap for your dealer. And if your problem goes away, that was it.

Is there a way to test the relay with a Volt / Ohm meter??

The dealer is working on this problem. The consensus is that this was just a bad relay, though I'll know for sure in a couple of weeks once I fully test it. I'll post the results then.

dwayne wrote:The dealer is working on this problem. The consensus is that this was just a bad relay, though I'll know for sure in a couple of weeks once I fully test it. I'll post the results then.

Are you positive you didn't accidently bump the kill switch??

In all the fuel injected cars and motorcycles I've owned, I never had a fuel pump relay fail. Although I did have one fuel pump growl at me.....Audi.

Ed..

ebiker wrote:

dwayne wrote:The dealer is working on this problem. The consensus is that this was just a bad relay, though I'll know for sure in a couple of weeks once I fully test it. I'll post the results then.

Are you positive you didn't accidently bump the kill switch??

In all the fuel injected cars and motorcycles I've owned, I never had a fuel pump relay fail. Although I did have one fuel pump growl at me.....Audi.

Ed..

Ed, I know it was the relay for the following reason: the fuel pump would not come back on UNTIL I tapped the top of the relay for the fuel pump. The dealer also tried to get the pump to work by making sure I followed a proper startup procedure. Trust me, it was the relay, or something else in the pump, but for now it looks like the relay is at fault. We also made sure that the gas cap was properly closed, and again it WASN"T UNTIL THE RELAY WAS TAPPED that the pump started working.

dwayne wrote:

ebiker wrote:

dwayne wrote:The dealer is working on this problem. The consensus is that this was just a bad relay, though I'll know for sure in a couple of weeks once I fully test it. I'll post the results then.

Are you positive you didn't accidently bump the kill switch??

In all the fuel injected cars and motorcycles I've owned, I never had a fuel pump relay fail. Although I did have one fuel pump growl at me.....Audi.

Ed..

Ed, I know it was the relay for the following reason: the fuel pump would not come back on UNTIL I tapped the top of the relay for the fuel pump. The dealer also tried to get the pump to work by making sure I followed a proper startup procedure. Trust me, it was the relay, or something else in the pump, but for now it looks like the relay is at fault. We also made sure that the gas cap was properly closed, and again it WASN"T UNTIL THE RELAY WAS TAPPED that the pump started working.

OK, you have me convinced the relay is defective. Now, replace the relay and go riding.

Geezzzz,

Ed..

Just as soon as the part comes in. I'm still riding, trying to reproduce the problem, but I can't. The problem is not coming back and is not predictable. I'm trying to figure out what condition needs to exist for the failure to occur. So far I can't reproduce it.

When the first 600 mile service was done on my R1200C, the mechanic had the fuel tank off the bike. It turns out, he did not make sure the power plug to the fuel pump was properly seated. I found that out going down mountain in a tightening right hand turn and the motor stopped cold. The bike got to be a handful in a hurry. He later said he was sorry and they put a stay-con wrap around the plug assembly.

Just like in an airplane, the first few trips after a service are the opportunity for the operator to discover the "quality" of the service work just completed. Hopefully, death is not the result of the defective workmanship!

dwayne wrote:Just as soon as the part comes in. I'm still riding, trying to reproduce the problem, but I can't. The problem is not coming back and is not predictable. I'm trying to figure out what condition needs to exist for the failure to occur. So far I can't reproduce it.

Don't you hate it when that happens. So much nicer to have something just 'break' and be obvious about it. I hate those devious gremlin faults.

Oh I know, its those damn intermitint problems that are the hardest to solve. If it breaks then you know what has to be done, but when it only happens sometimes without what seems to be any rhyme or reason... I know there is a commonality here, just can't find it. Worst thing is; it hasn't happened since. Wierd. Maybe its my other bike giving bad Karma or something cause I left it high and dry.

dwayne,

Dude, you are going riding! Just switch the relay with the one next to it on the other side of the middle partition. It's the horn relay and it's the identical part.

To be sure we are talking about the same thing . . . look at the group of 4 small black relays top center of the pic. The horn is 2nd, the fuelpump is the 3rd one. You can also switch with the others, but they are for the Motronic (#4) and the Load Relief (#1) which is all the things that shut off when the starter is cranking (Lights).





After you switch them (observe that the bike's female sockets are not oriented the same way) you may want to blow the horn a lot until either:

--The fuel pump quits again and THAT wasn't the problem

-or-

--The horn doesn't work every time you try over a number of weeks.

The pic I chose was an existing one in my gallery so I used it. At any rate, the dealer tech should have known they were interchangeable and at least given you a bike that runs (without a reliable Horn!).

I had this exact problem with an Ed 80 Rockster. It turned out to be a defective hall effect sensor. If the ECU does not receive a signal from the sensor on the crank it assumes the bike is not turning over and shuts down the fuel pump. Mechanic at BMW had seen the same symptom before and only found it after changing just about everything on some poor unfortunate owners bike.

Cyclebob, thanks for that. The manual is great at telling you what fuses do what, but nothing about the relays.

Bump

Hmmmm . . . Bad Hall sensor. That would make the bike stall and turn off the fuel pump -but- why would tapping the relay make the pump run again? Swapping the relays will still give a pass/fail result.

I'm wondering if Hall sensors are randomly failing -or- are they just good ones being ruined by routine overheating?

CycleRob wrote:Hmmmm . . . Bad Hall sensor. That would make the bike stall and turn off the fuel pump -but- why would tapping the relay make the pump run again? Swapping the relays will still give a pass/fail result.

I'm wondering if Hall sensors are randomly failing -or- are they just good ones being ruined by routine overheating?

I think the relay is deffective. I've been reading about relays of late, and it would seem from what I have read that my most likely issue is the relay. I won't know though until its changed I have run it for a few weeks. Gets changed on Tuesday.

Dwayne,

I could understand the problem being a relay fault if the contacts failed to close when the relay coil is first energised, this is indeed a common symptom of relay failure. If the energising coil closes the contacts it would be unusual for the contacts to drop out, but then close again because you tap it! It could however be a wiring fault to the relay (check the connections to the relay socket) as tapping it, or pulling the relay out and pushing it back in, may move things enough to close a broken wire in the wiring loom or relay/fuse box.