2nd Gen Non-Engine/Transmission Idle speeds and cruise control cable

[DNewell]

Okay TDR fans, I've got a couple of questions that I'm just dying to have answered.

My cruise control has been acting a little strange. When I initially set it, the speed of the truck just keeps going. I have to press the coast button and it will eventually get the speed back in control. However, when on level ground, the truck tends to surge quite a bit. It just can't hold an even speed with the cruise control. I pulled the battery box out, checked out the vacuum lines as far as I can trace them, and since then, I haven't had a chance to get it on the highway. I ended up replacing two rubber lines right at the one-way valve coming off the vacuum pump. Everything else looked good. My question is that when I pulled the cover off the housing where the cruise control cable and the throttle cable mount, there appeared to be about 1/8-1/4 inch worth of slop in the cruise control cable. It doesn't appear that there's any way to adjust the cable.

Also, when I'm coasting to a stop with my foot off the throttle and the truck in neutral, the idle speed is near 900rpm. When the truck slows to less than 7-8mph, the idle drops down to the 800. Are these trucks supposed to do this? If not, anyone know of a cure?

 

[HFreeman]

See TSB 08-16-95A. Cruise must be set with pressure on accelerator. Otherwise it will develop a 'memory'. Cure is to set and turn off about 10 times while accelerating.

 

[Crash_AF]

Mine does the same thing with the cruise control 'running away' when set. Just started doing it.

The TSB listed above does not apply to the 24V and describes a completely different problem.

Does anyone else have insight into this problem?

Thanks,
Joe

 

[WDaniels]

Mine did and does the same thing. The "turning it off and on 10 times with constant pressure on the pedal" is a royal pain in the @#$. The fastest way is to disconnect the batteries negative side for a minute or so to erase the memory. I did the test and mine came back with the code of 34, meaning that the "whatever you call it" under the left battery is bad or you have a vacuum leak.

WD