Hello everybody, I’m kind of new. Sorry for this long post, but I am hoping to be as accurate as possible.
I have read a lot of this site for a while and recently bought a 88 iroc-z with a 5 speed and 5.0 tpi. Slowly finding the problems with the car but so far I am very happy with it.
Now the real reason I am writing this post is to ask some opinions. I found that there was no light in the check engine light location, put one in and it’s on; Big surprise. Ran the codes, and I have codes 34, 36, 44 (I know what the codes mean, just trying to find the causes).

I have worked on diagnosing the code 36. It might not be the correct Burn-off relay but do not know how to identify the relays. Now with that said, I am able to ground the wire at the ECM and the relay works and turns on. So I tested the outputs of the ECM, and I believe (this was a few months ago) it was only able to produce a 1 volt drop across a 10kom load. This tells me the ECM is bad, or maybe a bad connection.

How does the ECM normally go bad, and could that cause the other codes? OR should I check my fuel pressure/vacuum leaks, so on..? Any ideas/recommendations would be helpful.

Now what the car does: runs great wide open throttle, loves being above 2k rpm. When it is under 2k rpm in normal driving conditions it shakes/shudders. When lower and around 1000-1500 rpm, the idle jumps around, and makes it very difficult to drive. Sometimes the idle will kick up to about 1500, and I have to let off the gas, then all the sudden it drops back down and I have to be on the gas. This makes the car very difficult to drive around parking lots, or city streets smoothly. Note: when just idling the rpms will fall to about 1200-1500, stop for a second then fall to about 800-900, and remain fairly stable.

Now would these codes/bad ECM cause this low rpm difficulty? Do you think replacing the ECM will fix all these problems? If the ECM is only causing the Burn-off relay problem, is it a transistor output stage/ could I replace the bad transistor? also, convince me to buy the OBDI/usb cable so I can connect my laptop.

Already checked:
TPS
Set idle according to this site – at the time it would not idle stable below 600, very shaky.
Two of the spark plugs appear to be in good condition
All Maf relays work.

P.S. If you guys want I will take some pictures and post them later.

 

Vacuum leak.

 

awesome, somehow I wasn't thinking it was a vacuum leak, but that would really make sense. That could cause the 34, and 44 codes too.

Ok then, the CCV port on the throttle body, will it let air in because I know that hose is cracked, but thought it was only an outlet. if that is it I will feel pretty stupid.