Sounds like he's not getting crank signal. Either its the PCM or its a bad sensor, bent-broke-missing reluctor wheel or just a cut or broken wire somewhere. If the PCM is signalling the fuel pump to run for about 3 seconds when the key turns on then I think the pedal assembly may be okay. I wonder if the camshaft is even turning. Did someone sneak an LS2 or foreign camshaft into the engine? It may not have a timing ring on it that is required on the Gen3 engines.
See my truck data in the "My Garage" section here... http://www.ls1truck.com/forums/my-ga...tml#post191709
Yep. CKP is one of the only 12v sensors.
If you had a scanner you could tell if there is cranking RPM. That could rule out a CKPS. Since these coil near plug IS have the ICM built into each coil, it's a little more difficult to do simple tests on each coil. In the fixin' world there is usually only a miss, etc. so swapping coils from one cylinder to the next is a valid test.
Not here.
I suck at retrofit conversion questions 'cause I have no idea what the swap stuff is based on. If I knew what model year range the harness was based on it would be 3 minutes to narrow the problem since you have three dead circuits (probably more) that can almost be guaranteed have something in common.
03 5.3/4L60e
96 gmc.
well now we are cooking...so pin 12 should be getting power? Is that 12v switched or constant 12v
something else we noticed, with the new harness there is a purple I believe, marked crank, we got nothing from that wire, maybe its a signal wire, not sure, but I do know, we got nothing power or ground wise from it regardless of key position.
The fuel pump was working from the first attempt at a start (even with the bad pedal sensors). We heard it come on each time, checked for pressure, its there, smell of fuel always there for a few minutes after cranking.
Last edited by LSXmyford; 08-12-2008 at 05:31 AM.
LSX conversions, so easy a caveman can do it.
purple crank wire usually goes to the starter solenoid if you hooked up the starter relay setup in the harness. I normally use the factory starter wire.
See my truck data in the "My Garage" section here... http://www.ls1truck.com/forums/my-ga...tml#post191709
Ya know, thats what we thought, engine would not crank, we used a test light on it to be sure it wasnt the starter...got nada...in the key start position.
so he just used the original wire, cranks fine.
would this be a clue to something else?
Last edited by LSXmyford; 08-12-2008 at 07:27 AM.
LSX conversions, so easy a caveman can do it.
nope, should not affect it at all.
See my truck data in the "My Garage" section here... http://www.ls1truck.com/forums/my-ga...tml#post191709
if that is the crank solenoid wire, why isnt it get positive voltage?
bad pcm?
LSX conversions, so easy a caveman can do it.
The crank solenoid wire is a 12v high amperage lead coming from a relay that is triggered by energizing the relay coil via the ignition switch. It's probably not hooked up correctly. The relay should have a 12v source going to it, the purple wire out to the starter solenoid, a ground and a power source for the relay activation coil. The power can be jumpered from the main 12v coming from the battery and then ground can trigger the relay or the relay can be grounded and the other lead can be a low amperage 12v source from the ignition switch. I'm not sure how the ignition switch sends the crank signal, grounding a relay circuit or powering one. Dependant up the signal type will tell you how to wire the relay.
See my truck data in the "My Garage" section here... http://www.ls1truck.com/forums/my-ga...tml#post191709
You should have a yellow wire from the ignition switch that goes through the C100 connector to the neutral safety switch. From the neutral safety switch out you'll see a purple wire that goes to the starter relay to ground. The side of the relay that makes contact will have a 12 volt signal from the battery and goes to the solenoid purple wire on the starter itself. Hope this helps.
Last edited by NITROUS; 08-12-2008 at 10:32 AM.
97 GMC, 2002 LS6.
1991 GMC Syclone #1428
Does it supply power or ground to the relay?
See my truck data in the "My Garage" section here... http://www.ls1truck.com/forums/my-ga...tml#post191709
Posting Permissions
Reply With Quote
