weird stuff on cold start-up; thermowax?
 

1990 N/A stock except for racepipe.
These problems started occuring around the time I adjusted my TPS. I made no other adjustments at the time.
First, the car goes straight to 3000 rpm. It never used to do this. If it put in gear the idle goes back down, if I take it out, it shoots right back up again. I am familiar with the 3k warmup but today it went to 3k even thought I started the car in gear.
Once the car warms up for a few seconds, the idle starts to bump up and down, like its a bad BAC or something, yet I have no accessories on. It generally revs up to about 2500 then settles back to ~1500; then it jumps again. This continues on for about 1-2 minuted depending on whether I just let it sit or put a load on it. I think this is thermowax related but I have no idea how to check it.
Once the car is fully warmed up the idle is almost perfect at 700 RPM's. I know the TPS is set correctly so I don't understand how it could be related to the cold-start occurances, yet the problems started right away. I have adjusted the TPS a few time before that and always notice that it seems to effect the warmup process is this possible? Where should I start looking?
One more thing, my check engine light keeps coming on. I know how to check the codes; ground the initial set coupler, turn the ignition on and read the check engine light for the code(s). But I can't seem to get any codes to show up even though in the past I had no problem it was the 02 sensor. Any tips or tricks for reading the engine codes? I suspect I am not getting a good ground. . .
sorry for the lengthy post any help?
Joe

up

Your first problem sounds like it is definately the thermowax. You can either replace it or remove it with the TB mod. With the ECU, unplug the battery, hit the brakes to release any left over voltage in the ECU then recheck the ECU codes to see what you have.