Testing coils on a coil over plug system?

[art leong]

Originally Posted by buzzinhalfdozen

Art, the sensor should work correctly using any voltage within it's operating range, in this case more is not realy a good thing. You can test this sensor very easily... take your volt meter hook into the sensor signal wire( the one sending voltage back to the ECU) hook other meter lead to ground. Power up system so sensor has power, next pass a metal object by the sensor, you should see the signal voltage "toggle" switch from 8 volts to 0 volts. I've found it's best to check this at the ECU to verify the signal is getting to the ECU. If you see no voltage switch at the ECU, next try the same test at the sensor connector, if you now see switching then you have a simple wiring issue between the 2 devices. Please try this test and let us know the results. By the way I also noticed that you need to set the "trigger pull up resistors" in your trigger1 and trigger2 sub menus, this is set correctly?Another consideration is the polarity of your crank sensor, being a VR type sensor you really need it wired correctly, I know from experience that they will work even if polarity is reversed however not correctly. To figure out the polarity requires the use of a "scope" unless of course the sensor supplier supplied this info to you.

Thanks. the polarity on the crank sensor was checked on a scope whe we put the system in. It was a 50/50 shot of getting it right. and I got it wrong.
The cam sensor I have now shows nothing when I pass a magnet past the eye. It shows no voltage when I connect the postive to my tester and the neg to the ground. Soo it seems shot.
I will check the lines leading to the sensor. But I think the sensor was the problem.
I do everthing by myself on the car and could not watch the light on the sensor and put it in gear alone. On hindsight I could have rigged up some mirrors like I do to see if the wheels are turning, when on the jackstands.
I'm going to get a spare crank sensor. Have it's polarity checked and put it on to make sure it works. The wiring from both sensors is shielded and not grouded seperately (it's grounded in the ECU). So it isn't an antenna.
I'm hoping the changes in vibration on the motor when putting a load on it caused the sensor to fail, then correct itself on restarting. When I jiggled the wires. I made the problem permanent instead of intermittant.
Is there any benefit to running 12 volts, from the on switch. Instead of the 8 volts from the ECU?

I want to thank all that have helped so far. My understanding of the entire engine control system has progressed a lot. The first year and a half my ECU was a mystical majic box. That I had no idea about anything to do with it. I made some attemps to tune it, but usually forgot to press the enter button or the save button. While there is still an awful lot I don't know about it. Now when I read the help section on my ECU I can understand a lot more.
Like when I was thinking about changing the voltage to the cam sensor. I went to the wiring diagram and didn't see a 12 volt supply (there are 5 and 8 volt supply's). I realized that the 12 volt positive going to the ECU could be used.
Sooner or later I'll learn.

And Adger. I'm keeping my limbs crossed till I get the sensor. But I will trouble shoot everything else that I can just to have some info to go on if I have another problem. Thanks.