TurboTnZ06
Go on red!
- Joined
- May 7, 2002
Where is the ground for the ecm reference voltage?
Months ago, went racing, ran 10.5 @ 129, drove home. I lost spark to #6 cyl a couple days later. Replaced cam sensor, replaced wires. Set camsensor, started car right up perfect, but, still lost #6. Swapped plugs, ohmed wires, ohmed coils, all seems ok. Now it won't even start. Give it gas and it barely runs and backfires. Sounds like a cam sensor problem. Reset cam sensor a dozen times from scratch, finger in hole of 1, rotate to 25 ATDC, rorate cam sensor CW at 7+v, then CCW until the volt drops, tighten. It also matches almost where I removed it taking the twisting out of a tooth of the oil pump drive slot into consideration -I always take a pic when I remove cam cap to see what the window orientation is so I could drop it back in close to then assume #1 compression if volt drop is in the ball park when setting it, but turns out had to reset old school just to be safe.
Fully charged battery, shows 12.8 on batt charger. Battery shows 12.8v on voltmeter, Pos batt to frame ground is 12.8v. Alt to frame is 12.6v Fuse box batt to frame shows 12.4v, ignition switch power key off to frame shows 12.4v. Scanmaster shows 12.0v key on. Replaced ignition switch, same. Crank, the volts on scanmaster drop to 10-6-7-8v and flat line around 7-8v.
Powerlogger works fine, I can log starting and it too shows the low ecm voltage.
I tried different cam sensor caps as well.
Could a bad ignition module suck the power and still not fire up?
Next steps - test with known working ignition module and coilpack. Test different ECM. Sell car to buy twin turbo kit for the vette...
Months ago, went racing, ran 10.5 @ 129, drove home. I lost spark to #6 cyl a couple days later. Replaced cam sensor, replaced wires. Set camsensor, started car right up perfect, but, still lost #6. Swapped plugs, ohmed wires, ohmed coils, all seems ok. Now it won't even start. Give it gas and it barely runs and backfires. Sounds like a cam sensor problem. Reset cam sensor a dozen times from scratch, finger in hole of 1, rotate to 25 ATDC, rorate cam sensor CW at 7+v, then CCW until the volt drops, tighten. It also matches almost where I removed it taking the twisting out of a tooth of the oil pump drive slot into consideration -I always take a pic when I remove cam cap to see what the window orientation is so I could drop it back in close to then assume #1 compression if volt drop is in the ball park when setting it, but turns out had to reset old school just to be safe.
Fully charged battery, shows 12.8 on batt charger. Battery shows 12.8v on voltmeter, Pos batt to frame ground is 12.8v. Alt to frame is 12.6v Fuse box batt to frame shows 12.4v, ignition switch power key off to frame shows 12.4v. Scanmaster shows 12.0v key on. Replaced ignition switch, same. Crank, the volts on scanmaster drop to 10-6-7-8v and flat line around 7-8v.
Powerlogger works fine, I can log starting and it too shows the low ecm voltage.
I tried different cam sensor caps as well.
Could a bad ignition module suck the power and still not fire up?
Next steps - test with known working ignition module and coilpack. Test different ECM. Sell car to buy twin turbo kit for the vette...
