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Please help with ignition problem Posted by Paul [Email] ![]() ![]() |
Thanks for taking your time to help me with this. My car is a 1990 900S (non turbo).
Symptoms: No spark.
Tests conducted:
1. Checked plug wire and rotor resistances. These were a little outside of parameters but I wouldn't think this would cause no spark. Rotor was normal. Primary high tension lead was 1500 ohms. Spark plug leads were 5300 ohms. They looked good, clean, no obvious problems.
2. Knock sensor tested. No response but probably OK. Also shouldn't cause the no spark symptom.
3. Checked for power to the EZK Control Unit. Battery Voltage between pins 6 and 20. (With connector unplugged and ignition on) Read ~ 12 volts
4. Checked for power to the amplifier. Battery Voltage between pins 4 and 2 on fender mounted amplifier. (With connecter connected and ignition on.) Read ~ 12 volts
5. Checked for power to the coil. Battery Voltage between terminals 15 and ground with ignition on. Read ~12 volts. Note: I also measure 12 volts between terminal 1 and ground. Is this a problem?
6. Checked the coil primary and secondary circuit resistance. (with ingition off and all wires removed from the coil) I got 0.9 ohms between terminals 1 and 15 (within limits) and10,500 between terminal 1 and center tower (this is outside of the allowable of 7200 to 8200 ohms but I would be surprised if this would cause the no spark symptom) Should I replace the coil?
7. Checked the amplifier switching function. Connected a voltmeter between coil terminals 15 and 1 and turned the ignition on. Initially this test failed so I replaced the amplifier. After that it worked fine with the voltage rising to 5.2 volts, then dropping back to 0.
8. Checked the pulse signal from the EZK control unit to the amplifier. The instructions on this are confusing. It sounds like I should be reading between pins 5 and 2 on the control unit but there are no wires on these terminals. I tested it instead between pins 5 and 2 on the amplifier. According to the book, I should turn the motor with the starter and the voltage should oscillate between 0 and 8 volts with average of 2.8 volts. I was getting a steady 8 volts. Could this be caused by the oscillation being too fast for my voltmeter which then read the highest voltage of 8 volts? Either way the instructions say that if I have any faults to go on to the next step.
9. Check the Hall sensor signal to the control unit. This test initially failed producing a steady 0 volts. I changed the hall sensor and then the test worked OK with the voltage switching from <.4 volts to >3 volts, back and forth.
The instructions say that if no faults are found that the contol unit is probably faulty and should be replaced. I did this and still got no spark. I have since checked everything again with the same results as above.
At this point I am lost. Any help for ideas would be appreciated.
Thanks,
Paul Dyson
posted by 198.81.2...
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