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Followup To
Question -
hello jason.
i have oscilating power out of the distributor wire
which is going to the ignition control unit.
i do not have any oscilatng pwer on the coil both
terminals show 12 volt.
could it be a defective power stage
or is the control unit bad?
ed
Answer -
Hello Jason,
Thank you for your prompt reply.
My car stopped suddenly. After trying to restart it, it cranked over, but did not start.
Examination showed that I did not have any spark on any of the spark plug wires.
The coil has two primary wires, # 10 and # 1.
# 10 wire is power wire and has 12 Volt from the ignition key
# 1 wire gets its pulse from the power stage.
The power stage is located inside the engine department (left front. mounted to the fender)
my measurements were made on this power stage. I do not get any oscilating power or pulses on pin # 1 of the power stage.
Also I do not get any pulses into the power stage on pin # 5, which comes from the ignition control unit (black box), located inside the car, on the driver side under the steering wheel.
Like you mentioned, the coil sends a high voltage to the distributor, which in turn
sends a pulse of high voltage to each of the four cylinders. In order for this to happen you need a pulse train on the primary winding of the coil.
That is the pulse I do not have.
I checked the power stage in a different car. It worked.
Is the problem in the black box or could it be in the distributor?
Hope to hear from you
Thank you
Ed
Your question is worded a bit confusing. The coil sends high voltage to the distributor which in turn sends a pulse of current to each of the 4 cylinders one at a time as the engine cranks. So in a sense, you should be getting a pulsed, oscillating current to each spark plug. Is that where you were making your measurements? I'm not sure what you meant about the ignition control unit, but I suspect that it is also normal for it to receive a pulsed current as well. Could you explain in more detail what is going on?
AnswerBecause you tested the power stage, I think its the ignition control unit. I highly doubt a problem with the distributor, especially if you're not even getting a pulse the coil. To be absolutely sure, you can pull the main center wire out of the distributor cap and test for spark there. I would try testing your control unit in another car, I'll bet you find it doesn't work. Another possibility is your ignition itself might not be sending a proper signal when you turn the key. Worth a check if your control unit ends up working. Good luck!
