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Help!! '02 R1100S Won't Rev

rxcrider

New member
I got a 2002 R1100S a couple weeks ago and it ran fine. Tuesday I rode it to work and when I got on it to go home I saw the low fuel light. I stopped and filled up. On my 35 mile ride home it started surging and wouldn't rev all the way to redline. It made a "bogging sound" when opening the throttle all the way. The idle dropped from the usuall 1100 to 900 and by the time I got home I needed to keep pumping the throttle to make it up my street at 5MPH. I assumed I got bad gas and picked up a new filter the next day. After draining the tank and running the fuel through a paint filter it revealed NO DEBRIS. Inspection of a sample in a clear glass jar SHOWED NO WATER OR DEBRIS. I refilled with NEW FRESH GAS from another station and it's no better. It was poppin' through the airbox and generally running like crap. Here's what we have done so far

1. Drain fuel install new filter with fresh gas...No Change
2. Swap Coils.... No Change
3. Check Fuel PSI... It's 25PSI @ idle dropping to 21PSI when reving engine. I think this is too low?
4. Cleaned HALL SENSOR's.... It actually is alot better now, But still not right.


Any other ideas? NEED TO GET IT FIXED ASAP! Got a ride next weekend and local BMW dealer can't even look at it for 2 weeks.
 
Thats weird... Check your air intake and air filter...but mine was doing pretty much the same thing and it ended up being the fuel pump. Good luck, and let us know the end result.
 
I got a 2002 R1100S a couple weeks ago and it ran fine. Tuesday I rode it to work and when I got on it to go home I saw the low fuel light. I stopped and filled up. On my 35 mile ride home it started surging and wouldn't rev all the way to redline. It made a "bogging sound" when opening the throttle all the way. The idle dropped from the usuall 1100 to 900 and by the time I got home I needed to keep pumping the throttle to make it up my street at 5MPH. I assumed I got bad gas and picked up a new filter the next day. After draining the tank and running the fuel through a paint filter it revealed NO DEBRIS. Inspection of a sample in a clear glass jar SHOWED NO WATER OR DEBRIS. I refilled with NEW FRESH GAS from another station and it's no better. It was poppin' through the airbox and generally running like crap. Here's what we have done so far

1. Drain fuel install new filter with fresh gas...No Change
2. Swap Coils.... No Change
3. Check Fuel PSI... It's 25PSI @ idle dropping to 21PSI when reving engine. I think this is too low?
4. Cleaned HALL SENSOR's.... It actually is alot better now, But still not right.


Any other ideas? NEED TO GET IT FIXED ASAP! Got a ride next weekend and local BMW dealer can't even look at it for 2 weeks.

Hi rxcrider, it sounds like your looking for some quick help. To make this easier for someone that has had the same problem to spot-I'll add the yr, mod, and problem to your title. Good luck, Gary
 
What about the fuel pressure regulator? Do they go bad? And can somebody confirm I should have 42PSI fuel pressure?

20-25 PSI is really low right?
 
What about the fuel pressure regulator? Do they go bad? And can somebody confirm I should have 42PSI fuel pressure?

20-25 PSI is really low right?

Fuel pressure should be 43.5 PSI according to the shop manual.

I would not jump to the pressure regulator without first making sure the fuel filter clamps and fuel lines are ok. Also double check the condition of the fuel pump filter sock.

Another common thing people seem to find is the throttle cables not being seated correctly in the throttle bodies at the adjusters. The cable sheath gets hung up and the bike won't run right and makes the huffing type noises.

Also check where the throttle cables wrap around the spindles on the throttle bodies and make sure no little pebbles are stuck in there. This happened on my 96 RT several times!

Pressure regulator failures are pretty rare I think. Filters and fuel pump problems are way more common.
 
Fuel pressure should be 43.5 PSI according to the shop manual.

I would not jump to the pressure regulator without first making sure the fuel filter clamps and fuel lines are ok. Also double check the condition of the fuel pump filter sock.

Another common thing people seem to find is the throttle cables not being seated correctly in the throttle bodies at the adjusters. The cable sheath gets hung up and the bike won't run right and makes the huffing type noises.

Also check where the throttle cables wrap around the spindles on the throttle bodies and make sure no little pebbles are stuck in there. This happened on my 96 RT several times!

Pressure regulator failures are pretty rare I think. Filters and fuel pump problems are way more common.

Agreed on all the above points re pressure. The pump is actually good for more than twice the pressure ( I momentarily pinched the line to see over 90 psi on the test gauge)
25# seems too low for high rpm operation.
If you do track down to the regulator, PM me as I have a low mileage one.
Back on Sunday nite.
 
Final Chapter:

Checked fuel pressure again this morning and it showed 25PSI no matter if I pinched the return line or not. That took the regulator out of the scenario. I figured it was a fuel pump problem. I drained the gas, removed the tank and noticed the rubber line AFTER the fuel pump and BEFORE the fuel filter wasn't too nice. I removed it and saw alot of cracks and 2 actual blown out small holes. I replaced the bad line and I am happy to say ALL IS WELL in BMW LAND! SO apparently the tank of gas was just a coincodence. The RIDE IS ON!
 
Final Chapter:

Checked fuel pressure again this morning and it showed 25PSI no matter if I pinched the return line or not. That took the regulator out of the scenario. I figured it was a fuel pump problem. I drained the gas, removed the tank and noticed the rubber line AFTER the fuel pump and BEFORE the fuel filter wasn't too nice. I removed it and saw alot of cracks and 2 actual blown out small holes. I replaced the bad line and I am happy to say ALL IS WELL in BMW LAND! SO apparently the tank of gas was just a coincodence. The RIDE IS ON!

Beauty eh? Don't you love it when you get off easy? :clap

Checking the easy obvious stuff first pays good dividends sometimes. Enjoy your upcoming ride!
 
Final Chapter:

Checked fuel pressure again this morning and it showed 25PSI no matter if I pinched the return line or not. That took the regulator out of the scenario. I figured it was a fuel pump problem. I drained the gas, removed the tank and noticed the rubber line AFTER the fuel pump and BEFORE the fuel filter wasn't too nice. I removed it and saw alot of cracks and 2 actual blown out small holes. I replaced the bad line and I am happy to say ALL IS WELL in BMW LAND! SO apparently the tank of gas was just a coincodence. The RIDE IS ON!

Thats great news!!! BUT....Where did you get the gas line to replace your old one???? Regular gas line is not made to be surmerged in gas. I found some on line,but your dealer should have it also. I'm just trying to save you from a future problem.
 
The hose came from a 1996 R1100RSL that I'm parting out. It didn't show any signs of softening or cracking so we went with it. For now, he's up and running. In the near future, all the hoses in the tank on both his '02 S and my '95 RS are going to be replaced. I'd hate to have this happen on the road somewhere.

The R1100S with the failed hose is about to belong to a friend of mine, Mike, and he's been doing the typing in this thread. He is in the process of trading a KTM 950 ADV for the R1100S and had just had the S delivered from CA. He put about 100 miles on it and the hose failed. Thanks for the help, everyone. If that kind of quick response isn't enough to get a new beemer owner to join the MOA, I don't know what is. Hopefully Mike will be on here with his own account shortly.

- Jonathan
 
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