another rough idle.

[colebrian69]

well posted this once in the wrong section oops.

but anyways i have an early 99 f250 with 207k miles but only about 10k on rebuilt motor. im having issues with a rough idle when i instal my tunes or when i do the 10k mod. it has been slowly getting worse for some time now.

it only does it when its warm and only with tunes or 10k mod. when there removed it idles fine but still even lacks the stock power.

-runnin on w85 but problem was there before i started running it

-replaced ICP,IPR,Injector O rings, diy fuel pickup mod

-my icp when warm idle is around 500psi

-my fuel pressure when warm is 50-60psi but it drops fast when giving it some throttle.

had a buddy scan the truck, no codes except for for my gutted ebpv, it passed the contribution test and the injector buzz test.

im a college student and cant afford to keep throwing parts that dont work on it. im stumped so im hoping someone smarter than me can help out.

Thanks in advance,

Brian

[Turbostang500]

What tuner?

Where are you reading the fuel pressure?

[colebrian69]

bully dog gt, getting fuel pressure from the fuel bowl after the filter

[Turbostang500]

Fuel filter been changed lately?
That could explain the pressure drop.

I really dont know how that tuner works.
Does it intall into the icp harness?

[colebrian69]

changed the filter couple weeks ago cause it was clogged, and the bully dog gt plugs into the obd port.

im having a hard time diagnosing a fuel issue or a hpo issue

thanks for the help by the way

[Turbostang500]

I dont think im offering much GOOD help! Lol

Are you saying you dont know how to diagnose either of those or you dont feel those are the problem?

[colebrian69]

I know its one or the other. Just not sure which lol.

[Turbostang500]

What is w85? Is that a bio diesel?
If so, can you try regular diesel just to rule things out?

[colebrian69]

yes w85 is a biodiesel. i thought about swapping it for some regular diesel but i had the issue before doin the swap.

its doin it now without any sort of tunes on it. so its def not a tune issue

forgot to say its got a the 50 cent mod so not a uvc gasket problem