hello again, i have yet another issue. when my truck is cold, mainly in 2nd and 3rd gear if i give it any more than a little gas it bucks and jumps so bad i need to push in the clutch. if i mash the gas it is also fine, but i dont always want to be full throttle. after it warms up it doesnt seem to have the same problem. could this be ignition related or what? i am a little confused right now. thanks for any help

 

i'f you press a little does it bog and stumble? and then if you open wide open does it bog a little and then catch and go on? a vacuum leak would act like this. to prove it yes/no, cap off all vac lines at the manifold and test it. caution you may not have power brakes.

 

i have wondered about the vacuum thing, does anyone have a vacuum diagram for a 5 speed 5.9 4x4?

 

nobody has a vacuum diagram or anymore input on this situation? i really want to resolve it! thanks

 

There should be a sticker under the hood. If not, maybe it's in the FSM you can download from the FAQ section. Actually, now that I think of it, you could have an issue with the precat o2 sensor. Or ECT sensor.

 

O2 sensor makes sense, as when you step hard enough on the go pedal, the PCM goes into open loop, and basically ignores what the senor is telling it. Unplug it, and take it for a ride. Problem gone? Replace it.

 

theres no vacuum diagram in the pdf that i could find, and the one on the truck i dont think has much bearing on the true routing for me, because the truck originally had a 5.2 auto, and now its a 5.9 5 speed. my truck also needs a new exhaust put on it, i have a cat and a resonator but thats where it ends. i have a hole before the resonator, and i am pretty sure im leaking exhaust out of the manifold where it meets the y pipe. could this be the issue? i wouldnt think so, but what do i know

 

The vacuum should be the same and has nothing to do with the tranny. So how many o2 sensors do you see?

Check for codes.