Engine/Transmission (1994 - 1998) P Pump throttle stuck. Not cable or linkage!

[MBanning]

I have a 98 12 valve. The throttle hung on me and I need to get to the bottom of this.

The fuel shut off has been eliminated and replaced by a cable in the cab. The throttle cable and all linkage and springs have been recently replaced. I have no AFC and run Scheid's adjustable fuel plate. Its pretty simple. I also have 4000 RPM governor springs.

With the engine not running I can take the throttle rod off the throttle lever and manually move the lever. Doing this with the fuel plate removed there is a place near 3/4 throttle where I can feel tension and If I push past this point the lever moves easily again. Moving the lever back toward idle is the same. The tension on the pump lever is enough to keep the throttle return springs from pulling back to idle. This has caused the throttle to hang near wot and can make for an interesting ride. The fuel shut off cable does function and will shut down the truck when this happens.

If anyone has any experience with this or can offer any advice on how to repair I would appreciate it. Thanks for reading MBanning

 

[MBanning]

No replies?

 

[fest3er]

Is there any sign of rust on the shaft? My '98 was hanging up a little around 1400 RPM. After liberally dousing both ends of the shaft a few times (WD-40, #2, PB BLaster, 30W oil), the rust finally let go and it's behaved since. You don't seem to be in rust country, so rust might not be the problem. Mine has seen its share of road salt here and up north.

 

[MBanning]

Thanks fest3er but no rust on the truck and spotless under the hood.

 

[Missouri Mule]

Could be a problem inside the p7100 pump. GAmes had a problem with his throttle linkage (some type of plate) it was binding up. He found parts for it, but you replaced your linkage.