What killed my computer?

[gearheadboy]

Is this my demon?

Hey all I was reading this post. My car is an 88GT with a speed density conversion. I just bought it and it runs good...ehhh..ok. Has alot of goodies added. It starts and does the weird idle cold, stalls etc. COLD. Warm it idles ok.It smells horribly rich. Burns your eyes but no smoke. It does not have cats on it. I did the base idle reset, checked the tps .99v, cleaned and then replaced the IAC. I tried to pull codes with my Snap-on scanner. At first I got KOER 12 99 44. KOEO 85 11. My smog stuff is unhooked/gone. Then after I went to get paper to write them down to look on here, I went to run them again...the scanner just stares at me..times out. Wont give me codes. After cycling power to the scanner and wiggling the underhood connector etc. I finally was able to get codes KOEO but not KOER. And now I cant get either. Is my ECU pooped? I forget the number of it but when I looked it up it is for an 88 5spd. MAF. HELP?

 

[gearheadboy]

Oh and I forgot to mention that the IAC sometimes doesnt seem to do a thing. I'm seriously thinking I need a new computer...Input Please?

 

[tmoss]

There is a hardware difference between an auto processor & a manual processor. The difference is because of the way the NDS [neutral drive switch, manual transmission] & the NSS [neutral safety switch, auto transmission] are wired. They are both wired to the same pin#30 but the auto trans wiring grounds the pin to the starter solenoid & the manual grounds to signal return, during crank mode there is a voltage spike sent to pin-30 so the auto trans processor has a diode on pin 30 where as the manual processor doesn't, most of the time this won't cause a problem unless you get into a prolonged crank condition.

Those that want to convert their automatics to manuals, and swap the ECM, need to clip the wire going to pin 30 (You can also install the diode) or else the ECM will fry the pin 46 trace off the board leaving the sensors with no return path. This also leaves the manual EEC unable to dump codes, which looks for the loop through the neutral sensing switch of the T5 transmission.

Make sure you have a 5 speed O2 sensor harness when using an A9L or you will fry the trace also. The damage is common when people mismatch harnesses and use an automatic O2 sensor harness with an A9L computer.