keithw1975

Well, my '98.5 Dodge Cummins has been having trouble with the lift pumps but it turns out that it isn't the fault of the pumps. For some reason they aren't getting current all the time from the wiring lead. I had been able to get around this by unhooking the battery leads< which I had been doing anyway when replacing lift pumps< making me think they were bad. After hooking the old ones up to a 12 volt source though they seem to be working fine.

Yesterday I headed down to KC and stopped down there and put in about $30 worth of fuel which isn't much anymore. After doing so it wouldn't start and I saw and heard my lift pump not running. I cycled the key off and on to no avail but then found out that leaving the key off for about 30-45 sec would cause the lift pump to run and then it started.

Later that evening I was heading back from South KC. I had shut off and started the truck about 6 times with no problems. I was getting down to about an 1/8 tank so I decided to get some fuel. As usual when I take off the gas cap it makes alot of noise sounding like there is a pressure difference and I fill up but only put in $25 and then shut the truck off while I went in to pay and use the facilities. When I cam back out I couldn't get it to start. The lift pump also wouldn't run if you bumped the starter like usual. It would run for 3-4 sec if you cycled the ignition but would do nothing when bumping the starter. Finally after try to start it with no luck I went in and ran a positive wire to the lift pump from the battery so the lift pump was running continuously and was reading 13# of fuel pressure. Even with that the truck would just crank but not start.

One more thing to add is that for a while I was having my parking brake and ABS light randomly come on as well as the Check Engine light but all that just stopped a few weeks ago. Does this sound like a PCM problem or do you think the VP-44 went out? It is my second VP-44 and it has about 50,000 miles on it. I was luck that there is a small Dodge dealer only about 6 blocks from where my truck died so I am planning to tow it there for a diagnosis Monday.

Update:
Today the guy from the dealer said he went to look at it and it fired right up. He said the mechanic couldn't find any problems with it and there weren't any codes set. He thought the computer on the injector pump might be overheating and then working when it cools down. I am guessing I am stuck until it fails again.

Thanks,
Keith

rich

wouldnt hurt to see if any codes can be pulled up

keithw1975

The dealer said there weren't any codes set. Do you mean I should double check them?

Keith

lsenus

Check your tank vent on top of the sending module. I've never had a presure change sound when refueling mine. It could be that the vent is plugged and not allowing air in as the fuel level drops.

keithw1975

I will take a look at that. Mine has had that wooshing sound when fueling ever since I bought it.

greasemonki

My truck doesnt make any noises when I remove the fuel cap either. Sounds like we might be on to something here...keep us posted

keithw1975

I still haven't checked for a fuel vent obstruction but I do think I found my problem. After checking the grounds on the body they were very rusty. I cleaned them up and sanded away the paint under the washers. For the last two weeks it has been running like a champ.

Keith