New to the site, and I like what I see so far.

Problem: my truck has been lacking power and seems like it's mis-firing more now. It just started backfiring under a load. Not all the time, just when I take off from a stop and the RPMs drop to 500 (manual). I've heard it could be the fuel pump, but I'm not sure. Plugs were replaced with champion truck plugs, problem still persisted. Changed the plug wires to mopar performance ones, still there. If it is the fuel pump, where is a cheap place to buy it? So far, the only place I've seen is the stealership.

Oh, one more thing to add. When the RPMs are up around 3-4, it doesn't do it (at least that I can tell). Under 2k and especially under 1500, it does it big-time. Starts bucking like wild. Haven't ran a fuel pressure check on it yet, but I'm pretty sure the fuel filter/pump is the original one (165k).

 

not sure what year the truck is but I'll take some shots in the dark.

if pre 98 check the distributer, you might need a new cap and rotor.

post 98 you might have a gunked up injector

fuel pressure as you said might also be a culprit, around 12 psi is what you need. also with that mileage I would do a compression check and make sure you dont have a warn out cylinder.

 

I didn't think the V-10's had distributors...at all.

 

just covering all the bases

 

Yeah, no distributor on this pig. Just 2 coil packs on the pass. side valve cover. At first I thought it was an ignition problem. But after gapping the plugs correctly and changing plug wires, I have reason to believe it's a fuel problem. Just wanting to make sure, and get some other opinions.

 

If it is the original fuel pump you are overdue to changeit. I think they are to be changed every60-100kbecause the fuel filter is attached to the pump. Mine showed up going up a hill under load and the engine started bucking.

 

hey it sounds like your map sensor is bad, it sounds like it is loading up under pressure

 

Great site. This is my first visit. I have a 98 V10 with 75k miles. It's my commuter truck. Today I noticed a loss in power going up a hill then an odd idle at park. Basically everything is bone stock and original. Sounds like it might be fuel related. I'll check pressure tonight. Any other suggestions?

Checked the pressure tonight - 50psi. The book says 35-45 psi and if higher, the regulator/filter unit might be the problem.

 

RockAuto.com has the pumps for $170, however they also list a fuel pressure regulator separately. for $100. It looks as if a new pump would come with the new regulator on it though.

 

I am having the same problem... mine is 2002, 30k,
Let me know what fixes it.