BCCHowdy
Registered Member
Hello!
I just finished a TPI swap on my '85 Chevy Blazer and would definitely appreciate help troubleshooting the gremlins I have. I had this same running setup in an '84 GMC pickup which sat for 10+ years. I pulled the motor and hardware, ECM was trashed (mice), rebuilt the motor and got a new Painless wiring #60102 for the install. Everything is in, wired, connected and I got an 1227165 ECM from a scrap yard out of a corvette.
When I turn the key to the 'on' position the fuel pump comes on and stays on. It should only cycle for 2 seconds then off, but it just stays on the entire time. Jumping A & B on the ALDL connector does nothing, no codes, not even 12. I also remember when keying on and the pump cycles for 2 seconds the SES light should come on until engine start, but nothing. I tried connecting TunerPro RT with my laptop and ALDU1 adapter... nothing. Engine will crank but no fire. I figured with the ECM not even giving me code 12 when I jumper it something else is going on. Since the ECM was a scrapyard pull I swapped it with a reman with the same result. (wasted $$$)
One thing that's irritating about the Painless Wiring kits is you don't get an actual schematic. It's nice that everything is labeled for install but once it's installed, loomed, and tucked away where it's supposed to be it's difficult to troubleshoot. There are two capped fuses in the Painless Wiring harness, one with red wires with a 30 amp which has power, the other is a 15 amp with purple wires and no power. I think this might be the crank wire from the starter solenoid so that makes sense. I didn't check for power on the 15 amp when cranking.
B1 connector at the ECM has power
A6 connector has power when key is in the 'on' position
I did not check for power at C16
I did not connect the oil pressure switch wires to anything, they're tied off.
I removed the fuel pump relay and have power at on the green/white wire when key is on as expected, but it stays on which is unexpected.
I checked for power at on the green/white wire and also the tan/white wire with the ECM removed per another thread to look for voltage that shouldn't be there.
It's like the ECM is only half powered. I don't get it. Grounds are good. I cleared off the paint on the firewall and bolted the ground eyelet there. I measured no voltage drop from there to the negative terminal on the battery. I even ran a wire from the eyelet on the firewall direct to the battery to eliminate any other potential ground issues. No change.
I'm not sure what else to try, but this is super weird behavior. Any suggestions would be greatly appreciated.
(I posted this same message over at ThirdGen.org as well looking for help)
-Howdy
I just finished a TPI swap on my '85 Chevy Blazer and would definitely appreciate help troubleshooting the gremlins I have. I had this same running setup in an '84 GMC pickup which sat for 10+ years. I pulled the motor and hardware, ECM was trashed (mice), rebuilt the motor and got a new Painless wiring #60102 for the install. Everything is in, wired, connected and I got an 1227165 ECM from a scrap yard out of a corvette.
When I turn the key to the 'on' position the fuel pump comes on and stays on. It should only cycle for 2 seconds then off, but it just stays on the entire time. Jumping A & B on the ALDL connector does nothing, no codes, not even 12. I also remember when keying on and the pump cycles for 2 seconds the SES light should come on until engine start, but nothing. I tried connecting TunerPro RT with my laptop and ALDU1 adapter... nothing. Engine will crank but no fire. I figured with the ECM not even giving me code 12 when I jumper it something else is going on. Since the ECM was a scrapyard pull I swapped it with a reman with the same result. (wasted $$$)
One thing that's irritating about the Painless Wiring kits is you don't get an actual schematic. It's nice that everything is labeled for install but once it's installed, loomed, and tucked away where it's supposed to be it's difficult to troubleshoot. There are two capped fuses in the Painless Wiring harness, one with red wires with a 30 amp which has power, the other is a 15 amp with purple wires and no power. I think this might be the crank wire from the starter solenoid so that makes sense. I didn't check for power on the 15 amp when cranking.
B1 connector at the ECM has power
A6 connector has power when key is in the 'on' position
I did not check for power at C16
I did not connect the oil pressure switch wires to anything, they're tied off.
I removed the fuel pump relay and have power at on the green/white wire when key is on as expected, but it stays on which is unexpected.
I checked for power at on the green/white wire and also the tan/white wire with the ECM removed per another thread to look for voltage that shouldn't be there.
It's like the ECM is only half powered. I don't get it. Grounds are good. I cleared off the paint on the firewall and bolted the ground eyelet there. I measured no voltage drop from there to the negative terminal on the battery. I even ran a wire from the eyelet on the firewall direct to the battery to eliminate any other potential ground issues. No change.
I'm not sure what else to try, but this is super weird behavior. Any suggestions would be greatly appreciated.
(I posted this same message over at ThirdGen.org as well looking for help)
-Howdy
