Help!

[Five0786]

I'm having problems with my '92 Silverado. My torque converter will not stay locked up after the truck warms up. I've had it rebuilt due to the amount of mileage on it but after a new ecm, brake switch and prom it still refuses to work. The problem existed before the rebuild and now it will lock up until I've driven it 10-15 miles. After that it stays unlocked until it sits over night. The trans shop has narrowed it down to the ecm sending a power signal instead of a ground. Any ideas on what might be causing this?

 

[JJHUSSY]

I'm dealing with the same problem, I am pretty sure its my speed sensor..

 

[rhino]

It shouldn't be very hard to find out with a scanner on it that shows data... Watch the TPS sensor, the speed sensor, brake switch, ignition voltage. Something is commanding it to unlock. I'm sure they have replaced the lockup solenoid right? They have a tendency to hairline crack and only leak when it gets hot. Last resort would be put a "no wire lockup kit" in the valve body. It will lockup around 40 mph in 3rd gear automatically then.

 

[Five0786]

Have any idea where I can find said scanner? The only one I have access to just makes the engine light blink... My only other ride is down for a top end/timing belt replacement so I'm having to drive my truck. OBD1 hardware seems to be hard to find around here.

 

[Lazerbeans]

If it’s OBD 1 you don’t need a scanner to get a clue as to what’s going on. Find the Assembly Line Diagnostic Lead Connector, (ALDL) and ground out A & B and watch your flashes. Here’s a link to a full write up. http://www.s10planet.com/forum/showthread.php?t=3906 Not extremely detailed info from your computer, but a clue as to what’s going on. Just remember to remove the “lead” or your “check engine” light will go ape as you drive off and throw you for a loop, I know it did me.

 

[Lazerbeans]

Sorry, just saw you had a simple scanner; your already up to speed, as far as that. Need more coffee, I guess.

 

[Five0786]

Wound up tapping into the converter circuit right before the plug on the trans and running a lead into the cab. Hooked up a dmm and drove down the road. It has 13+ until it hits 45-50 mph then switches to a ground. So unless I'm missing something it's working as it should and the problem is internal...

 

[rhino]

I would look at that tcc sol. Take it off and see if you can blow in it. It has a check ball that will not seat sometimes. Also the valve in the pump is the lockup valve, it can be taken out with the pan off, its a pain though.