z28romance

hi everyone. this is my first post on thirdgen.org. hoping to find some ideas. as the title says i have an 87 z28 TPI 305. im having an issue with high choppy idle and engine stalling when placed under load (turning the wheels and shifting in reverse/drive). after several restarts my cel comes on. when the cel comes on the idle drops to where it should be and there's no stalling issue. im guessing a bad component and the ecm defaults when it doesn't get proper input. any help would be greatly appreciated.

update:

today i set the timing @ 8 deg. btdc. i jumped out the diagnostic port and pulled the dtc's. i got a code for the esc circut? also a code for mass air flow sensor and maf burn off circuit. since i had already repaced the maf burn off relay i went ahead and replaced the MAF sensor. the old unit was left in someones trunk for 6 mos by the P.O. of the car.

still stalling out. not idling so high though. when i disconnect the esc wire the car doesn't stall out. could this be a bad distributor component? im a little stumped. i have experience in the aftermarket parts industry but i need help with diagnosis. im getting sick of seeing all these summer nights go by and no cruising. any ideas? anyone?

utilityguy2

iTrader: (1)

I think your on the right track. Fix the error codes and all will be well. What codes do you get? ESC is the knock circuit. When you say "unplug the ESC" do you actually mean the EST bypass? When unplugging that you will get a code 42. That is normal. When you unplug the EST bypass wire you are taking the ECM out of the timing equation. It runs on whatever your intial timing is. in your case 8 degrees. Make sure you set that back to 6 degrees when all fixed so it matches the ECM's initial settings. My thought is something in the MAF system. Also check fuel pressure and bad spark plug wires for cross arcing. could be bad ECM also.

z28romance

electronic spark control was what my haynes book called it, i believe. i did get a code 42 but this was before i unplugged the est connector. the maf wires and connector look good all the way back into the loom. the wires are new but they look like junk, car quest, dont know if these are any good. the PO just laid them anywhere. no looms.