92 automatic in and out of overdrive/or lockup contantly.............

[ballpeen]

i have a 95 and am familiar to the tps as i have to clean mine once in a while. but a freind has a 92 and has been told it is a black box on fenderwell. 400 dollars and sometimes it doesn't fix the problem. i am looking for the best way to remedy this so he can use his overdrive again and have no future problems. thanks very much in advance for any info you could offer.

 

[Philip]

The black box on the fender well is the PCM. Power train control module. Lets look at other items first.



The TPS on his truck is located on the VE pump. At the front of the pump and on top. There are noted problems with it. The orange wire is the return voltage signal wire. Hook up a volt meter acros it and the white wire. You should be showing around . 75 volt to 1 volt at idle position. Slowly open the throttle. The voltage should raise in a smooth steady motion. If it doesn't time to replace it. (You can do this with the engine off with the key on).



The next thing to check if the TPS shows as good. Is the plug beside it. This has been noted as a problem area. Unhook the plug and look into the female side. There are small tabs that rub against the the pins of the other side of the plug. Take a small screw driver and bend these pins back out " GENTLY ". Then apply some dialetic grease.



Then I would check the RPM sensor air gap. It should be around . 050" or so. If the air gap is good then check the plug at the front of the cylinder head that leads down to the RPM sensor. Check female plug side like the TPS. This plug likes to do the same thing and a loose conection here will cause OD to hunt around.



The last thing I would check is the pins on the plug going into the PCM. On my truck the wiring harness is tight going into the PCM. This had caused strain on the terminals and had opened the female terminals up. The TPS signal wire is on the center row, second terminal from the front of the truck.



Do each one of these checks and repairs one at a time. Test drive between each one. This way you will know what caused the problem. If you do everything at once you might not every know what caused it.



You need to go into your user control panel and put what state your in. There might be someone close that can help. The user control panel is located in the discussions forums drop down list.

 

[JFaughn]

also check to see if the brake sw. is to close to pedle and turning it off when you go over bumps,shaking the pedle and hitting the sw. just a very little, I'ld hot glude a small washer on the foot of the sw.

 

[ballpeen]

that is awesome, thanks alot. i will print this out and we will run all these checks. i can spell words usually, just get in a hurry while typing. thanks again.