Engine/Transmission (1994 - 1998) Rough start at half tank fuel

[Djowell]

Winter is definetly hear in the northeast kingdom vermont. Now my truck is difficult to start only when the fuel tank gets to 1/2 full. I changed the low pressaure hoses in the summer. What else do I need to do?



1996 2500 4x4



Thanks for any help



Dennis

 

[JFaughn]

Fuel pressure test , may be lift pump & or overflow valve .
I had starting problems at about 1/4 tank , took the LP apart to find bad valves , then did a pressure test , it turned out low , so an OFV .
Now all is good .
Pressure test , should be 18 -22 lbs idle , 25 -35 lbs 1,600 RPMs no load .

 

[Dr.Bob]

Get a fass.

 

[Joe G.]

Dennis,



Email me at -- email address removed -- for my 12 valve fuel system writeup, how it works and how to fix it.



It's may be the lift pump, but there are quite a few much more likely suspects for your problem. And cheaper.

 

[EKlem]

Is the problem truly related to the amount of the fuel in the tank? Is it in any way related to whether you are parked on a hill? If the problem is related to the amount of fuel in your tank, you may have a pinhole in your pickup in the tank. I have run into this only a few times and never on a dodge truck but it is possible.

Start by reading the writeup from Joe G. He really knows these fuel systems well and does a good job of indicating what the likely suspects are and how to test them.

 

[Djowell]

Guys,

Thanks for all the help. It must be time for a winter project. I'll report back how and if I can fix the problem. 3' of snow now in the driveway here in VT- ugh!

 

[Djowell]

Get a fass.

Dr. Bob

Now I'm lost what is a fass? Must be my winter brain in action. Help

 

[Missouri Mule]

A Fass is an after market electric fuel pump used on primarly on the 24 valve and common rail engilnes (also 24 valve).

The mechanical lift pump on the 12 valves are usually reliable but I have read where a they have bit the dust.

Do a fuel pressure test, pinch or clamp the return fuel line. If the fuel pressure goes up it is your overflow valve if pressure stays the same or goes up slowly it is your lift pump.

 

[Joe G.]

It's way more likely that it is an air leak than the lift pump.

 

[Dr.Bob]

You still have a syphon feed put some pressure on it, plus no more filling the filter.