Adam McLaughlin
11-23-2003, 04:08 PM
TBI Chevy Guys, Throw me a bone.
I am doing a motor swap into a 1985 GMC half ton truck. I am using a 1993 350 from a suburban.
I listened to the suburban at the yard, and it started right up and purred like a kitten, first bump of the starter.
I get it home, install it, plug everything in, and wire it up. Damn truck won’t start unless I “prime” it by putting a teaspoon of gas into the throttle body, and then cranking it. At that point, it will run, although somewhat poorly until I shut it off again and try to start it.
I have the wiring set up in a stock configuration. The orange wire to ECM B is always hot. The Pink wire that goes to the coil is hot when In run or start. The pink wire with the black stripe is hot when in run or start, and the red wire for the injectors is hot when in run or start.
I do have the diagnostic connector hooked up, I do not have the 4L60E plugged in. The truck motor ran without the 4L60E at the yard, so I am trying to duplicate this same situation.
The error codes I get when I try to start it, or get it running say code 43 – Electronic Spark Control Module………..
Another odd observation I have is that when I shut the system off, (power off to the red/black wire that feeds the ecm) the check engine light stays on for another 3 seconds. That’s bizarre.
I have another distributor, I have tried swapping it.
I have another computer, I have tried swapping it.
No difference.
When the truck is running, I observe the timing to dance between 8 degrees and 20 degrees at idle. I see the injector pulse width to go between 100 ms at off to 2.0 and such when idling.
If you romp on the gas quickly with it idling, the truck will stall.
What’s up with this guys?
I have gone to the library and photocopied the mitchells manuals regarding the wiring diagrams. I have hooked up things the way I think they should be,
I have checked for a dying power voltage when cranking, all wires going into the PCM are at least 11.5 when cranking.
Can someone throw me a bone?
Adam
I am doing a motor swap into a 1985 GMC half ton truck. I am using a 1993 350 from a suburban.
I listened to the suburban at the yard, and it started right up and purred like a kitten, first bump of the starter.
I get it home, install it, plug everything in, and wire it up. Damn truck won’t start unless I “prime” it by putting a teaspoon of gas into the throttle body, and then cranking it. At that point, it will run, although somewhat poorly until I shut it off again and try to start it.
I have the wiring set up in a stock configuration. The orange wire to ECM B is always hot. The Pink wire that goes to the coil is hot when In run or start. The pink wire with the black stripe is hot when in run or start, and the red wire for the injectors is hot when in run or start.
I do have the diagnostic connector hooked up, I do not have the 4L60E plugged in. The truck motor ran without the 4L60E at the yard, so I am trying to duplicate this same situation.
The error codes I get when I try to start it, or get it running say code 43 – Electronic Spark Control Module………..
Another odd observation I have is that when I shut the system off, (power off to the red/black wire that feeds the ecm) the check engine light stays on for another 3 seconds. That’s bizarre.
I have another distributor, I have tried swapping it.
I have another computer, I have tried swapping it.
No difference.
When the truck is running, I observe the timing to dance between 8 degrees and 20 degrees at idle. I see the injector pulse width to go between 100 ms at off to 2.0 and such when idling.
If you romp on the gas quickly with it idling, the truck will stall.
What’s up with this guys?
I have gone to the library and photocopied the mitchells manuals regarding the wiring diagrams. I have hooked up things the way I think they should be,
I have checked for a dying power voltage when cranking, all wires going into the PCM are at least 11.5 when cranking.
Can someone throw me a bone?
Adam