Poor idle, and how to pull trouble codes? [Archive]

ak47

08-27-2007, 08:08 AM

I have an '86 305 TPI that I just installed in my pickup, I had the complete wiring harness (as far as I know) and just got it running. I put about 200 miles on the engine this weekend and it runs great down the highway, but off the start it is sluggish and it has a poor idle. It died out a few times when putting it into gear and starting out. Fuel pressure is good, and vacuum should be ok, no leaks as far as I can tell. It smells like it is running rich, could a bad O2 sensor be the cause, or do I need to go over everything again: IAC and TPS, EGR, etc... It initially had a problem with idle surge, but that fixed itself after driving a little.

Also, I wasn't able to find the diagnostics plug (ALDL) on the wiring harness. I think I have it, but it is on a string of wiring with a few other plugs that isn't plugged into the rest of the harness. Where does the check engine light wiring go back to, is it some pin on the ECM? Can I just get a bulb and hook up to an ECM pin to get the trouble codes, or do I need the ALDL plug?

Thanks for the help.

ak47

08-27-2007, 10:12 AM

... And I almost forgot... to add to the list of problems the engine refuses to start when it is cooled down (i.e. in the morning after sitting all night, or after several hours of sitting). It will just crank endlessly but doesn't start until it gets warmed up from cranking. I did set the timing already, its perfect, so what could cause cold start problems?