Reving 6.5

[wahoo2u]

A buddy had me take a look at his '94 yesterday. When you push the throttle down off idle and hold it steady, it will rev up to about 1300 rpm and then drop back to idle over and over. On initial startup, it really takes off! I plugged my scanner in, but no fault codes were set. Any ideas would be appreciated.

[landrea]

first off ,do you have a good scanner like the dealer? If so look at the feed from the throttle pedal and see if it fluxuates and if so its a bad pedal assy.The problem also could be in the computer.

[wahoo2u]

My scanner is an OTC Monitor Elite. Not a Tech2 like the dealers. The throttle position seems to be right on, showing 0% when closed and slowly increases while depressing the accelerator pedal. Also the reading didn't fluctuate with the increase in rpm's. One thing I did notice, what I think was the boost pressure was showing 13 psi. I know that is incorrect, as it was at idle.

[G. Gearloose]

I suspect thats 13 psiA.

[wahoo2u]

What's the difference? I think it read psi, but I'm not sure. I'm not even sure it was boost pressure. I think it read BS Press or BPRESS or something like that. I'm really just learning how to use this darn thing.

[Trae]

I had a similar problem I could not maintain a constant engine speed with out a load. touch the throttle and the engine would rev to 1500-2000 just let off a hair and strait to idle ended up replacing the Injector pump and crank sensor now the throttle response is smooth as silk.
The mechanic said it was the optical sensor.