LS1 in 3rd gen not starting??
01-07-2008, 09:24 PM
#1
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LS1 in 3rd gen not starting?? Ok so I installed the LS1/T56 into my 89 camaro and did the wiring myself. I hooked up my original ignition wire(PINK) to the power feeds for the injectors and coils. I connected my original starter wire(purple) to the LS1 starter and get the engine to crank. The crank sensor and cam sensor have been checked and they are working. I get power and ground to the coil and to injectors and have all grounds connected(have all three grounds connected properly to the head and another one to the firewall). The coil is ready to fire but is not getting the signal PCM to fire the coil. What would cause that??? And yes the computer is getting 12V as well..
01-08-2008, 07:48 AM
#2
There is another wire that requires straight battery power at all times to the pcm with a 10 amp fuse. Without it, it's probably never going to start. There are also two wires that power the coils and injectors. One for even and one for odd. Connector C1, pins 20 and 57 need battery power/10 amp. C1, pin 19 needs switched power, 15amp fuse. This is all based on a 99-02 pcm/harness.
Last edited by LS1MCSS; 01-08-2008 at 07:59 AM.
01-08-2008, 08:43 AM
#3
Does your service engine light self check when you turn the key? All the pink wires get switch, and then there are "always hot" wires just like LS1MCSS said.
I would double check your wiring... Go over every inch of it, and make sure your connections are good.
This is why I always suggest trying to use the 4th gen fuse blocks. You dont need to splice the engine harness at all. You can leave all your pink junctions and what not hooked up, and just add power to the fuse blocks. Its pretty easy to snip the wrong wire and kill a whole circuit...ask me how i know. haha.
What year is your motor/harness? How much of the harness did you delete when you were doing the wiring?
J.
I would double check your wiring... Go over every inch of it, and make sure your connections are good.
This is why I always suggest trying to use the 4th gen fuse blocks. You dont need to splice the engine harness at all. You can leave all your pink junctions and what not hooked up, and just add power to the fuse blocks. Its pretty easy to snip the wrong wire and kill a whole circuit...ask me how i know. haha.
What year is your motor/harness? How much of the harness did you delete when you were doing the wiring?
J.
01-08-2008, 09:07 AM
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There is another wire that requires straight battery power at all times to the pcm with a 10 amp fuse. Without it, it's probably never going to start. There are also two wires that power the coils and injectors. One for even and one for odd. Connector C1, pins 20 and 57 need battery power/10 amp. C1, pin 19 needs switched power, 15amp fuse. This is all based on a 99-02 pcm/harness.
01-08-2008, 09:10 AM
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Does your service engine light self check when you turn the key? All the pink wires get switch, and then there are "always hot" wires just like LS1MCSS said.
I would double check your wiring... Go over every inch of it, and make sure your connections are good.
This is why I always suggest trying to use the 4th gen fuse blocks. You dont need to splice the engine harness at all. You can leave all your pink junctions and what not hooked up, and just add power to the fuse blocks. Its pretty easy to snip the wrong wire and kill a whole circuit...ask me how i know. haha.
What year is your motor/harness? How much of the harness did you delete when you were doing the wiring?
J.
I would double check your wiring... Go over every inch of it, and make sure your connections are good.
This is why I always suggest trying to use the 4th gen fuse blocks. You dont need to splice the engine harness at all. You can leave all your pink junctions and what not hooked up, and just add power to the fuse blocks. Its pretty easy to snip the wrong wire and kill a whole circuit...ask me how i know. haha.
What year is your motor/harness? How much of the harness did you delete when you were doing the wiring?
J.
01-08-2008, 09:36 AM
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Yeah I got that down thanks. Now this might be a stupid question but does my third gen have an ignition relay? Reason I'm asking is because I've been going through some threads here in LS1tech.com about "no spark" and they seem to fix the problem with a new iginition relay. If I don't have one would I need to install one or do I need a specific one? Thanks again.
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01-08-2008, 08:32 PM
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How can I check if a crank sensor is bad? I checked the sensor with a test light and every time it cranks the light would blink on and off. This to me indicates it's good or do I need to further test it? Just to give you all a little more info. The injectors are pulsing and I do have 12V and grounds to the coils but I am not getting the signal from the PCM to fire. This is a hard one to figure out.
01-09-2008, 10:26 AM
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Wouldn't this be the same as checking for spark with a screwdriver? because that's the way I've been doing it but how in the hell do you properly check the crank sensor?
01-09-2008, 10:55 AM
#17
Sounds like you have isolated your problem to the coil control signal. If thats the case I would then check that the PCM fuses are still ok.
2. Check the grounds behind the cylinder heads.
3. Double check for switched 12v with ign on at the coil connector.
4.Check for continuity between coil connector and pcm for the ref lo (purple wire) and ign control signal wire (brown)
5.If all check out, I would look for the problem elsewhere before considering the PCM as faulty.
As far as the crank sensor is concerned, you could use a scan tool to check for rpm while cranking. Im not sure where you can get one but maybe an auto place could loan you one.
2. Check the grounds behind the cylinder heads.
3. Double check for switched 12v with ign on at the coil connector.
4.Check for continuity between coil connector and pcm for the ref lo (purple wire) and ign control signal wire (brown)
5.If all check out, I would look for the problem elsewhere before considering the PCM as faulty.
As far as the crank sensor is concerned, you could use a scan tool to check for rpm while cranking. Im not sure where you can get one but maybe an auto place could loan you one.
01-09-2008, 11:08 AM
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Sounds like you have isolated your problem to the coil control signal. If thats the case I would then check that the PCM fuses are still ok.
2. Check the grounds behind the cylinder heads.
3. Double check for switched 12v with ign on at the coil connector.
4.Check for continuity between coil connector and pcm for the ref lo (purple wire) and ign control signal wire (brown)
5.If all check out, I would look for the problem elsewhere before considering the PCM as faulty.
As far as the crank sensor is concerned, you could use a scan tool to check for rpm while cranking. Im not sure where you can get one but maybe an auto place could loan you one.
2. Check the grounds behind the cylinder heads.
3. Double check for switched 12v with ign on at the coil connector.
4.Check for continuity between coil connector and pcm for the ref lo (purple wire) and ign control signal wire (brown)
5.If all check out, I would look for the problem elsewhere before considering the PCM as faulty.
As far as the crank sensor is concerned, you could use a scan tool to check for rpm while cranking. Im not sure where you can get one but maybe an auto place could loan you one.