chris123
Well-known member
I just purchased my 1986 Convertible 4+3 earlier this month, and am trying to get a bunch of stuff straightened out; the car never really had any power over 2,000 RPM's since I got it, so I was hoping that after my tune-up, it would be corrected, however it seems to be a little worse now; the check engine light will come on occasionally and I was able to pull codes 42 (Electronic Spark Timing (EST) & 44 (Lean Exhaust Condition); here is what I've replaced so far (all AC Delco parts)
Plugs
Wires
Distributor Cap
Rotor
Ignition Module
Oxygen Sensor
Coolant Temperature Sensor
Fuel & Air Filters
Even the sock filter attached to the in-tank fuel pump
Ignition timing set at 6 degrees
TPS set to .54 volts
Lightly tapped on the MAF sensor with no RPM change
I'm pretty decent with these L98's, however this has got me baffled; the car will sit there an idle perfectly, no missing or shaking; you can even rev it up and it sounds strong, however as soon as you get it over 2,000 rpm's when driving, it has no power and starts bucking and hesitating; it almost seems like the cats/exhaust is blocked; not sure if it could be fuel or ignition related; I did the diagnosis for code 42, and it led me to a possible bad ECM? Was going to try and replace the ECM and ESC Module to eliminate those 2 items; any additional suggestions before I take it to my mechanic? I went back over and double checked all my work, and everything looked fine, and as I said before, it still is showing the same symptoms (maybe even a little worse) than before I started my work; it's keeping me up an night trying to figure it out; wish I knew so I don't have to just throw parts at it...........
Thanks for any help or suggestions, Chris
Plugs
Wires
Distributor Cap
Rotor
Ignition Module
Oxygen Sensor
Coolant Temperature Sensor
Fuel & Air Filters
Even the sock filter attached to the in-tank fuel pump
Ignition timing set at 6 degrees
TPS set to .54 volts
Lightly tapped on the MAF sensor with no RPM change
I'm pretty decent with these L98's, however this has got me baffled; the car will sit there an idle perfectly, no missing or shaking; you can even rev it up and it sounds strong, however as soon as you get it over 2,000 rpm's when driving, it has no power and starts bucking and hesitating; it almost seems like the cats/exhaust is blocked; not sure if it could be fuel or ignition related; I did the diagnosis for code 42, and it led me to a possible bad ECM? Was going to try and replace the ECM and ESC Module to eliminate those 2 items; any additional suggestions before I take it to my mechanic? I went back over and double checked all my work, and everything looked fine, and as I said before, it still is showing the same symptoms (maybe even a little worse) than before I started my work; it's keeping me up an night trying to figure it out; wish I knew so I don't have to just throw parts at it...........
Thanks for any help or suggestions, Chris