Low power after long highway runs

[RamThatStroker]

Guys,



My truck (see signature) seems to lose power after sustained highway runs of speed ranging from 70-75mph. The truck seems to lag really bad and has little acceleration when compared to when the truck has just been used around town. Its sometimes so bad that it almost feels like its going die out when starting in 1st gear. Any suggestions would be appreciated. I have taken the cat off and have a K&N filter in the stock airbox.



Thanks,

Joe

 

[Dieselnerd]

If it's only after high speed runs and runs normally otherwise you can rule out things like pump timing. I doubt if it's a lube problem causing excess friction or it would overheat. It's probably fuel starvation leaving only a couple of things. Your filter could be clogged, fuel line coming from tank could be restricted or tank vent might be clogged or lift pump going bad. Do the easiest first, change the fuel filter and go from there. If you have a fuel pressure gauge you can check the lift pump pressure. After that it's not coming from the tank. That's probably the least likely. I hope this starts you in the right direction.

 

[BillGotthelf]

I agree with diesalnerd-My 96 did the exact same thing turns out it was the lift pump putting out 1/2 the pressure it should have.

 

[illflem]

If you had a fuel pressure gauge, as I do, you would notice on very hot days when the truck has been parked or on long runs when the fuel gets lower that the pressure will drop. I have never had performance problems from it, but my theory has been that hotter fuel effects the spring in the overflow valve causing the pressure to drop. It may cause a performance problem if your overflow valve is marginal anyways. Replace it, Piers has the best deal on them.

 

[RamThatStroker]

Thanks for the tips guys,



I will be updating my situation a. s. a. p



Joe