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I've been chasing an issue for a while now that I can't seem to figure out. I recently installed a 52mm throttle body onto my 86 since many said it would run fine stock. I reset the IAC and the TPS but noticed that once the car is warmed up it surges at idle but at only about 3 out of 5 stoplights I stopped at on my test drive. The car triggered a code 44 (lean exhaust) however the car seems to smell very rich. I used WinALDLl for the first time to figure out the issue and am having trouble understanding the info. In the flag tab I noticed that while idling, the "Rich Flag" and "EECC Slow O2 Rich/Lean Flag" would pop up every couple of seconds and then go away, rinse and repeat. the O2 voltage seemed to be moving back and forth as it should. Other than that I don't really understand the other counts.
I would really appreciate any info that would point me in the right direction of solving this problem!
Have you set the minimum idle after TB replacement ?
Yes I did. I have a haynes manual and I set the minimum idle speed and then the tps to .54v. However I noticed in the instructions you posted that you also have to unplug the timing connector which is interesting because It never appeared in my haynes manual…
Make sure your air tubes are tight and secure around the MAF sensor. Air leakimg in after the MAF will cause havoc.
Also, with the engine running make sure your TPS voltage (the voltage, not the %) is returning to .55 after the throttle closes. If the throttle shaft is binding at all and the the TPS voltage doesn't get back to. 55V, the ECM will do strange things. That happemed to me a few months ago and with mine it was a bad TPS. But since you have an aftermarket throttle body, it's something to consider.
Yes I did. I have a haynes manual and I set the minimum idle speed and then the tps to .54v. However I noticed in the instructions you posted that you also have to unplug the timing connector which is interesting because It never appeared in my haynes manual…
Set timing connection has to unplugged to set base idle, otherwise ECM will try to advance timing to achieve it’s target idle. Same reason why the IAC connector is removed.
In ALDL Mode (w-10 k resistor and while scanning with Win ALDL at 160 baud) it should idle at 1,000 rpm. The number of IAC counts and MAF (gm/sec) in a stable warm 1,000 rpm idle will provide a clue as to where you are with respect to the min airflow adjustment. You should see around 80 IAC counts at 1,000 rpm (a bit more than the middle of the range), assuming about 0 at 500 rpm, ~70 at 900 rpm and ~140 at 1300 rpm.
Normal (warm/hot) idle for an auto trans car (in gear) should be 550 rpm. Add 50 rpm for park/neutral.
WinALDL help/surging idle
