[rodeo joe]

This problem started on the way to Moab and contributed to the trip being kind of a bust for me. The idle is very uneven. It drops to almost stall then surges to 1000 plus RPM then drops again. Sometime it evens out to normal for a while but not for long. Frequently when I try to accelerate from a stop, it surges causing the truck to almost bounce. If I try to hold the accelerator steady it gets worse and more violent. I have to accelerate to about 3000 before it evens out enough to drive. This happened in Moab on my first real trail drive and cause me to have to slip the clutch so much that I had to turn back. Thankfully the clutch recovered when it cooled off and dried out.

Anyway, Now I have returned to home I am trying to diagnose this problem.
Have a new Bosch Fuel pump. Timing has been checked and in spot on10. Vacuum is around 16 - 18 mm Hg but surges and drops with the uneven RPMs. I've been working a lot but will have some time this weekend to mess with it. What else should I check and do the get Rodeport to running good again?

On a side note one of the best parts of the trip was meeting some of the wonderful folks from the planet. Really made the problems of the trip diminish. Thanks.

 

[psguardian]

It could be the ECU, or some sensor. Having to go deep throttle to smooth out makes me think a sensor is going bad, higher then normal electronic resistance means more input voltage is needed before you get a readable output for the ecm.

Fuel system: filter, fuel-pressure-regulator, evap return system, injectors.

Air system: MAF, intake seams, throttle position sensor, intake gasket / vacuum leaks.

Also is this throttle a cable driven or wire/electronic pedal set up?(if drive-by-wire check the electronics).

~psguardian

 

[rodeo joe]

So what you are saying is that it could be just about anything. :?

 

[psguardian]

LoL, I left out a whole host of mechanical causes. If I had to pick a starting point I would go with MAF & TPS.

~psguardian