I am seeking assistance for a problem I am having difficulty figuring out.

I have a 93 907 that was running fine up until the fuel pump went. I replaced the pump and shortly thereafter I started having problems with the bike starting and I noticed fuel pooring out of the exhaust on one side and it would not start. If it did, it was only because I had to give it gas and it sounded like it was running on 1 cylinder. I thought perhaps it was bad gas as the bike was sitting for a while. Then I noticed fuel getting into the oil crankcase. I drained all the oil, drained all the gas and took the whole bike apart. Fuel injectors are working and spark plugs have good spark. I thought perhaps it might be the fuel pressure regulator but had difficulty finding a replacement one. After dismantling everything and going through every part to ensure all was working, I put it all back together and put new fuel and oil, and now I still have the same damn problem.

Would anyone know what might be causing this problem?? Could this be the fuel pressure regulator?? The injectors appeared to be working fine.

Any help would be appreciated as I am going crazy about now.

ANTHONY

Anthony,

I don`t have a 907ie so no real idea what could cause the problem but I do have a few basic questions.
- as it worked before the fuel pump was replaced can you exclude that you didn`t connect the fuel lines incorrectly ?
- do you have compression ?
- if it differs, when was the last time valve clearance was checked ? Also do all timing belt marks align ? Not that one belt skipped a tooth (which I doubt)



G.

hi Anthony,
if the bike was working good before the pump went, and now causing all these problems, I would stop pulling everything apart and look at the pump first of all, is it compatible with the OEM pump? and connections, i cant think of what could cause petrol to end up in the sump, even if you reverse the connections...you didnt fit a diesel pump, extra pressure forcing heaps of petrol in motor, sump, exhaust pipes. the injectors can only handle so much pressure
keep calm and good luck

Paso750 and Claude:

Thank you for your assistance and suggestions.

The bike has compression, the fuel tubing connections are correct, and the timing belts are intact and in alignment.
I replaced the fuel pump and filter based on the recommendations I found from others on this site who noted compatibility. Here is the link for the bosch fuel pump that I installed:
http://www.euromotoelectrics.com/BOSCH- ... 576kit.htm

Is there a possibility that the problem is arising from a faulty fuel pump regulator??

ANTHONY

I haven't had too many (hardly any) mechanical problems with my bike, so Im not qualified, but i had a look at the fuel line setup and there are only two points that fuel can enter the motor, one is obviously the injectors and the other is through the rear of the fuel pressure regulator,
on this regulator there are delivery and return fuel hoses and also a smaller equalizer tube looks like on the other side of the regulator's diaphragm and the small tube goes directly into the intake manifold, if this diaphragm breaks or leaks, fuel will enter the engine, try removing this tube and see if there is fuel in it... my 2cw

fuel will also leak from the injectors if the regulator does not maintain the proper pressure

I took everything off again and got down to the fuel pressure regulator.
I removed the small tube that goes into the intake manifold and I found no fuel within the line. Thought I would see fuel and be more convinced the problem is the fuel pressure regulator which I still suspect it is.

Any other thoughts??

Thanks to everyone.

ANTHONY

I think you're right, either way, too much pressure or leaky regulator will cause this problem...you think...
just see if you can get a new regulator, they might not be that expensive, that would be the logical thing to do
then again ducatis are not always logigal

Hi Claude.

I now really think the problem is the fuel pressure regulator. When I took the small vacuum hose off, there was no gas that came out of the line. However, when I looked into the small metal adapter that accepts the small hose on the fuel pressure regulator, I found gas sitting in it......looks like I got my answer. I guess when the system is pressurized it ejects gas backwards into the intake manifold through the vacuum tube, but when there is no pressure the gas it goes back into the regulator. I found a pressure regulator that I orderd and I am waiting for it to arrive. I will keep you posted on how things go once I put it all back together.

If this is the problem with the pressure regulator, then I sure saved myself a ton of money doing it myself rather than taking it to the dealer and getting wacked in the pocket.

Thanks.

ANTHONY

You can test it by running the engine with the vacuum tube disconnected and the take off to the inlet plugged. You should see any fuel leakage pretty quickly. It will run ok without it, although since it has been designed to use it it is probably best connected. The pipe is not used on the later Ducatis and is left open to atmospheric pressure.

if it seems like it's only running on 1 cyl (half the power) it could be that when the fuel pump went by way of the dogs it shot some dirt or other foreign particles into the fuel line thereby clogging one of the injectors as well...
regards and good luck!
jason