Help - car will not start after battery drain
11-27-2001, 10:17 PM
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Help - car will not start after battery drain
Help!!! I have a 1991 C4 that does not start. When I turn on the ignition, the starter cranks but the engine will not run. The battery was drained and I recharged the battery. It is now at 12.2 volts nominally with the engine off. Prior to this, the car started fine.
I am new on this board and any help in isolating this problem will be appreciated.
Thank you,
-LL
I am new on this board and any help in isolating this problem will be appreciated.
Thank you,
-LL
11-27-2001, 11:23 PM
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Kevin,
I measured the voltage at the battery while the starter is cranking. The voltage is 10.2 volts. Additionally, I've checked the spark plug and verified that there is spark when the ignition is ON. My suspicion is in the fuel delivery system. I removed the DME fuel injection relay and noted that it cranked the same. So I measured the relay voltages during cranking:
Relay 1 (7), pins 85b to 87: 1.0 volt
Relay 2 (90), pins 85 to 86: 10.2 volts
I do not know what the first relay is used for, but it seems that 1.0 volt is unlikely to engergize the relay. The relay part number is 944.615.227.00. What could be causing the low energize voltage to the first relay?
-LL
I measured the voltage at the battery while the starter is cranking. The voltage is 10.2 volts. Additionally, I've checked the spark plug and verified that there is spark when the ignition is ON. My suspicion is in the fuel delivery system. I removed the DME fuel injection relay and noted that it cranked the same. So I measured the relay voltages during cranking:
Relay 1 (7), pins 85b to 87: 1.0 volt
Relay 2 (90), pins 85 to 86: 10.2 volts
I do not know what the first relay is used for, but it seems that 1.0 volt is unlikely to engergize the relay. The relay part number is 944.615.227.00. What could be causing the low energize voltage to the first relay?
-LL
11-28-2001, 12:49 AM
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Hi LL,
The DME relay fails often enough that many people keep a spare in the car.
The relay you have (944.615.227.00) is the original relay. The replacement relay is # 993.615.227.00. A cheap part, around $15. If it doesn't fix your problem, you can always keep it as a spare.
Here's an old (but good) thread on the DME relay:
DME Relay Thread
Good luck!
The DME relay fails often enough that many people keep a spare in the car.
The relay you have (944.615.227.00) is the original relay. The replacement relay is # 993.615.227.00. A cheap part, around $15. If it doesn't fix your problem, you can always keep it as a spare.
Here's an old (but good) thread on the DME relay:
DME Relay Thread
Good luck!
11-28-2001, 12:08 PM
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Thanks Randall, I will purchase the new DME relay. Looks like from the old thread regarding the DME relay that the original relay from the 944 may fail. I would still like to know what the energize voltage is for the 1st relay in the DME module. Is it a square wave? I was measuring the RMS value.
-LL
-LL
11-28-2001, 11:18 PM
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That's great!
Sorry I couldn't answer your square wave/sine wave question .... I would have to dig deep in the shop manual, and maybe find the answer. Anyway, doesn't matter now ... you've got a running car again
.
Sorry I couldn't answer your square wave/sine wave question .... I would have to dig deep in the shop manual, and maybe find the answer. Anyway, doesn't matter now ... you've got a running car again
.
