Black93lt1

When I ran the new wire I went close to the pcm straight to the tps connector

GaryDoug

IF you have cut the original blue wire at BOTH ends now so that nothing is attached to that wire in the middle section, then the PCM must be shorted. Do you have a source for the replacement pcm?

Black93lt1

Yeah I ran an external wire outside the harness to check and see if it grounded out to something else but there was no change to the voltage in the signal wire. No I don't have a source for a replacement other than the marketplace on here

GaryDoug

See post #15 of this topic. He is in the same boat maybe:
1993 TA - erratic gauges, engine shutting down ... - Firebird Nation

If you can spare the car for maybe 2 weeks, I can take a look at the pcm and see if I can repair it. You would only have to pay about $10-15 each way for ground shipping the pcm. And I can't guarantee the results will be successful.
In any event, let me know what the core charge is. I might want to buy your old one.

Black93lt1

Ok so I ship my pcm to u for the shipping price if u fix it...u ship it back at my cost...if u can't fix it then u buy it for the core charge from Oreilly's? Am I understanding that right?

GaryDoug

That depends on the core price. I will ship it back in either case if the core price is too high for my use. You can call places like O'reilleys to see what the costs are. It may depend on your area what they say.

GaryDoug

Update for the topic: I received the suspect 93 pcm from Black93LT1 today and did a preliminary test. The TPS input is not shorted and does test good over the entire range of input voltage. The TPS position values reported by the Tech II were correct. I will do a temperature box test tomorrow and see how it holds up at elevated temp. So far, it looks like I won't be buying a 93 pcm ;-) The OP has agreed to let me keep it over the weekend so I can work on supporting the 93 in my scan app.

Fatdog2

You folks are too high tech for me.But I gotta tell ya,I think you have a vacuum leak.If you have over 80,000 mi on the car ,I'm going with the intake manifold leak.My02.When you get the new gasket,it covers up that gap in the back of the intake manifold.Hope this helps.

GaryDoug

Update2: Tested the pcm at about 125 F for over two hours. No failure.

Fatdog2: The main indication is an electrical failure. The pcm has read too low voltage at the TPS. A vacuum leak could cause a high idle, but not the code 22 electrical failure.

Black93lt1

I still have the code 22 showing after putting everything back together bought a new connector and this is my second new tps I'm really confused on why it keep coming back on

GaryDoug

Unplug the pcm. Measure the blue wire resistance to engine ground. It should not read anywhere near zero ohms. When it does, you will have to dig into the harness and find out why and where. Another member of this or another forum had a very similar issue like yours. He never found the short, but he finally solved it by simply disconnecting both ends of the wire and bypassing it. I will try to find the topic.

Black93lt1

Ok thank you

Black93lt1

Update:

Engine revs to 2000rpm until it gets warm then drops to about 1500rpm (unless i put into a gear then it drops to about 1100 when its cold). i have searched for vaccum leaks but have yet to be able to find any.

Code 22:
i have yet to test the volts. I have however ran new wire between the gray and dark blue wire of the pcm to the connector and grounded the black wire to the alternator bracket (wasnt quite sure if it needed to go all the way back to the pcm being its just a ground wire). i pulled the pcm battery fuse out for 30 mins to get it to reset codes, and with no surprise the code showed back up.

Injuneer

You have to run the black wire back to the PCM. It's part of the 3-wire circuit. It's not just a ground.

Black93lt1

Ok well ill have to give it a shot in the morning im at work till midnight.

Would you happen to know which color of the pcm connector it is on?