PCM refuses to deliver spark
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Teching In
Joined: Aug 2016
Posts: 18
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PCM refuses to deliver spark Hi,
I am currently having a problem with no spark and no injector pulses on my LS1 -99. Here are some facts and background:
- One day recently it simply refused to start.
- The car is a Chevy Business Coupe -40 with 5.7L LS1 -99 and 4L60E.
- Wiring harness is PSI HAR-1016.
- VATS are disabled.
- It has been running fine for years and no modifications made lately.
- The battery is fresh and it is cranking as it should.
- The fuel pump is priming as it should and I have pressure in fuel rails.
- All fuses and relays checked and are ok.
- No spark at spark plugs while cranking!
- No pulse signal to the injectors while cranking!
- I have a good 12V from the ignition relay at the fuse/relay center of the harness.
- The HP tuner communicates fine with PCM and I can read the tune and scan for error codes.
- The codes I get from scanning is P0102, P0203 (I'm running in SD mode without MAF sensor), P1571(pending,history),P1689(ses,current).
I have allways had these codes and I don't think these are related to the problem.
- I verified with the HP tuner/scanner that the crank and cam sensors are giving signals as expected.
Now I'm completely out of ideas. Any hint or suggestion on what to do is appreciated!
Thank you!
I am currently having a problem with no spark and no injector pulses on my LS1 -99. Here are some facts and background:
- One day recently it simply refused to start.
- The car is a Chevy Business Coupe -40 with 5.7L LS1 -99 and 4L60E.
- Wiring harness is PSI HAR-1016.
- VATS are disabled.
- It has been running fine for years and no modifications made lately.
- The battery is fresh and it is cranking as it should.
- The fuel pump is priming as it should and I have pressure in fuel rails.
- All fuses and relays checked and are ok.
- No spark at spark plugs while cranking!
- No pulse signal to the injectors while cranking!
- I have a good 12V from the ignition relay at the fuse/relay center of the harness.
- The HP tuner communicates fine with PCM and I can read the tune and scan for error codes.
- The codes I get from scanning is P0102, P0203 (I'm running in SD mode without MAF sensor), P1571(pending,history),P1689(ses,current).
I have allways had these codes and I don't think these are related to the problem.
- I verified with the HP tuner/scanner that the crank and cam sensors are giving signals as expected.
Now I'm completely out of ideas. Any hint or suggestion on what to do is appreciated!
Thank you!
