I have a V-10 6.8 L engine in my 2000 Motorhome. Intermittently, it will sputter and stall. It then takes about 3 to 4 tries to get it started again. Once it fires up, it runs fine. I connected a fuel pressure gauge and it holds steady at 31 - lbs at idle. When it stalls, it reads 40 -lbs. Could that be too high? And if so, will the fuel pressure regulator be at fault? After I shut down, it will build up to 40-lbs and take about 3-hours to come back to zero. So, I don't think there are any leaks in the system. I will put a new fuel pump relay in as soon as I figure this out. But because it doesn't loose pressure, I don't think the relay is the problem.

There are no codes showing in the computer scan.

Any ideas?

Thank you
David

 

It doesn't sound like a fuel delivery issue.

When it stalls, is it a sputtering, cough, wheeze and stall, or is it a sudden, someone turned off the key stall?

 

Yes - I agree it sounds like a fuel problem. When idling, it will briefly loose RPM, sputter once and die. When trying to start it again. It will try to catch a few times. When it finally starts, it will run just fine. However, today, stalled while idling, while I was watching the fuel pressure gauge. It held at 31 and after the engine died, it slowly went up to 40. It was hard starting and when it did, it ran very rough for about thirty seconds. then smoothed out and ran fine.

I'm beginning to think that I may have some bad gas and the pump is picking up pockets of water in the bottom of the tank. Tomorrow, I am going to suck some gas from the bottom of the tank and see if that helps.

Thank you for your suggestions redford.

I will appreciate any more thoughts on the problem

 

Sorry redford. I misread your comment and wrote my reply before I read you correctly. You said you didn't think it was a fuel delivery problem. I am open to all suggestions. Because I have been working it as a fuel problem and maybe I have been heading down the wrong path.

Thanks again.

 

Contaminated fuel could be an issue. 31-40 PSI is not too high.

Let us know if cleaning the tank and fresh fuel fixes your issues.

 

First, let me tell you that it is an honor being helped out in this matter by a retired Master Sergeant. Thank you for your service.

If it is contaminated fuel, I have a problem because it is almost impossible to drop the tank. I can't get to it from the top because of holding tanks. And it is held in place by four heavy frame members. One of which has leveling jacks welded to it. So, what I hope to do is disconnect the fuel filter and attach a hose to the feeder hose and suck out the fuel from the bottom of the tank either with the existing fuel pump or if fuel will bypass the pump, maybe I can attach an auxillary pump to do the work. Well see. I'll let you know.

Thanks again for your help.