New LS7 crate engine won't start
#1
New LS7 crate engine won't start
Help! I have inherited someone elses problem child and I'm ready to beat it sensless.
Here's the rundown:
69 Camaro, New LS7 crate engine, no spark, no fuel from injectors, scan tool says 'link error'(Actron CP9145, the technician from a shop down the street even connected his GM tech2 scanner with the correct configuration(2006 Caddy CTS-V) with the same results). This is completely stock with stock pcm and harness(as far as I can tell). All I got instruction wise is the 2 page control system connection sheet, nothing else.
Here's what I've checked:
Battery hot and ignition wires to pcm-OK (after reading some posts, tomorow I will check for 12v when cranking), all grounds-OK, Pinouts for cam and crank position sensors-OK, Pinouts for DLC-OK, Ignition on-12v at coils and injectors, Ground (pcm) side of injectors do not go to ground with engine cranking, The MIL illuminates with key on, Fuel pump primes system but does not run when cranking(60 psi). I probably tried other things but this is all my brain can remember right now.
What concerns me most is the scan tool's failure to link with the pcm. Does this mean that the pcm is bad? I did notice probe punctures in the ignition hot wire at the pcm connector. The previous installer must have tried something, although I'm sure the engine was never started because the dry sump tank was not installed, nor was there any fuel in the fuel tank. Am I overlooking something obvious? Any ideas where to go next?
Thanks
Here's the rundown:
69 Camaro, New LS7 crate engine, no spark, no fuel from injectors, scan tool says 'link error'(Actron CP9145, the technician from a shop down the street even connected his GM tech2 scanner with the correct configuration(2006 Caddy CTS-V) with the same results). This is completely stock with stock pcm and harness(as far as I can tell). All I got instruction wise is the 2 page control system connection sheet, nothing else.
Here's what I've checked:
Battery hot and ignition wires to pcm-OK (after reading some posts, tomorow I will check for 12v when cranking), all grounds-OK, Pinouts for cam and crank position sensors-OK, Pinouts for DLC-OK, Ignition on-12v at coils and injectors, Ground (pcm) side of injectors do not go to ground with engine cranking, The MIL illuminates with key on, Fuel pump primes system but does not run when cranking(60 psi). I probably tried other things but this is all my brain can remember right now.
What concerns me most is the scan tool's failure to link with the pcm. Does this mean that the pcm is bad? I did notice probe punctures in the ignition hot wire at the pcm connector. The previous installer must have tried something, although I'm sure the engine was never started because the dry sump tank was not installed, nor was there any fuel in the fuel tank. Am I overlooking something obvious? Any ideas where to go next?
Thanks
#6
11 Second Club
iTrader: (1)
Check your GM Lan circuits from the DLC to the PCM.
DLC pin 6 tan/blk to PCM C3 53
DLC pin 14 tan to PCM C3 33
These both do through C105 - Engine Harness to I/P Harness, in the engine compartment to the right of the LF strut tower by coil 3.
The data link connector (DLC) is a standardized 16 cavity connector. Connector design and location is dictated by an industry wide standard, and is required to provide the following:
• Scan tool power battery positive voltage at terminal 16.
• Scan tool power ground at terminal 4.
• Common signal ground at terminal 5.
• Class 2 serial data at terminal 2.
• Keyword serial data at terminal 7, w/TR7.
• High Speed GMLAN (+) serial data at terminal 6, w/LY7 or LP1.
• High Speed GMLAN (-) serial data at terminal 14, w/LY7 or LP1.
DLC pin 6 tan/blk to PCM C3 53
DLC pin 14 tan to PCM C3 33
These both do through C105 - Engine Harness to I/P Harness, in the engine compartment to the right of the LF strut tower by coil 3.
The data link connector (DLC) is a standardized 16 cavity connector. Connector design and location is dictated by an industry wide standard, and is required to provide the following:
• Scan tool power battery positive voltage at terminal 16.
• Scan tool power ground at terminal 4.
• Common signal ground at terminal 5.
• Class 2 serial data at terminal 2.
• Keyword serial data at terminal 7, w/TR7.
• High Speed GMLAN (+) serial data at terminal 6, w/LY7 or LP1.
• High Speed GMLAN (-) serial data at terminal 14, w/LY7 or LP1.
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#8
I found the problem....The car was wired by a 3rd grader. This is the worst wiring job I've ever seen. The car has a Painless harness and the ign switched power source was the cruise control wire! That circuit is dead during start. I jumped straight from the ignition switch and it fired right up. Still won't link up with the scan tool though. Looks like I get to dig deeper.