poolguybri
Newbie
1989 Chevy K1500 5.7 350 TBI. Had motor professionally rebuilt and have been chasing electrical gremlins ever since. Truck ran fine before rebuild, aside from at end of life due to age. Engine was rebuilt to factory specs but with factory-style roller cam instead of the original flat tappet cam. I am experiencing rough / surging idle, especially once coolant temp reaches approx 110 degrees. Idle surges between roughly 575 and 850 rpm and runs rich. When driven for any length of time I get a code 43. I can hear pinging at idle, seems to get worse as engine warms up. I have observed the engine bay in total darkness and can see blue flashes at all 8 of the spark plugs. I can't actually see sparks arcing, but can definitely see blue flashes once my eyes adjust to the darkness. I'm not sure if this is actual arcing or "corona effect"??
All grounds are good as far as I can tell, and multiple "extra" grounds have been added.
Distributor has been replaced. Cap, rotor, and ignition module inside distributor have all been replaced repeatedly.
Ignition coil has been replaced and tests within spec.
EGR valve has been replaced.
IACV has been replaced.
TPS has been replaced.
ESC module has been replaced.
O2 sensor has been replaced.
Fuel pump has been replaced.
Spark plugs and wires have been replaced repeatedly. Spark plugs are gapped correctly to 0.35, are installed with copper antiseize, and torqued to spec.
Plug wires are run so as not to touch each other or anything grounded like firewall.
Plugs are AC delco conventional.
Thoroughly checked for vacuum leaks.
Performed compression test, all cylinders are within 10% of each other.
I have WINALDL and will post datalog. Scanner shows low BLM (confirms running rich).
I am about to light this truck on fire and push it out into the street. Any ideas????????
All grounds are good as far as I can tell, and multiple "extra" grounds have been added.
Distributor has been replaced. Cap, rotor, and ignition module inside distributor have all been replaced repeatedly.
Ignition coil has been replaced and tests within spec.
EGR valve has been replaced.
IACV has been replaced.
TPS has been replaced.
ESC module has been replaced.
O2 sensor has been replaced.
Fuel pump has been replaced.
Spark plugs and wires have been replaced repeatedly. Spark plugs are gapped correctly to 0.35, are installed with copper antiseize, and torqued to spec.
Plug wires are run so as not to touch each other or anything grounded like firewall.
Plugs are AC delco conventional.
Thoroughly checked for vacuum leaks.
Performed compression test, all cylinders are within 10% of each other.
I have WINALDL and will post datalog. Scanner shows low BLM (confirms running rich).
I am about to light this truck on fire and push it out into the street. Any ideas????????