Car not starting. Rapid clicking etc

TRIPPFONTAINE

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I'm getting a rapid clicking noise that seems to be coming from the ECU area - and my car ('72 3.0 CSi) is not starting. Dash light are showing, battery is showing full charge, starter motor is relatively new, Alternator is in decent shape and I'm running 123 ignition. Seems like it might be the ECU relay which looks pretty ancient and which I plan to replace. Just wondering if anyone's had a similar issue and what relay I should use in swop out?
 

scottevest

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I have a similar issue with my car clicks but if I just try a couple of times it always works. It’s only happens in intermittently. Curious what the solution is for you as it’s probably going to impact me eventually
 

Honolulu

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On my seldom-driven car, the first twist of the key after a week or two of sitting is usually met with a "click" as if the battery was only strong enough to actuate the solenoid and not spin the starter. Or maybe the ring and pinion were contacting but not engaging (I doubt this, but it's not impossible).

So I took the starter out (what a hassle!) and bench tested it; it worked fine. What I now suspect that the solenoid, which (1) pushes the pinion gear into the ring gear, and (2) switches current to the starter motor, isn't working correctly i.e., (2) isn't reliably operating.

The solenoid wires are soldered to the starter, thus to separate the two one will have to melt the solder and pull the wires off (the starter). Too much for me at the time; I greased the visible moving parts and reinstalled. Usually the starter will engage and spin the engine on the second or third try. The rest of the day it works fine and I won't mess with it further. Owners who are more particular about their cars may proceed further.
 

bill

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Assuming your ECU is under the right rear seat (and your coupe is otherwise wired the same as mine), there should be a relay next to it which operates the fuel pump. Check that. The ECU relay, also called the main relay, is under the hood (under the MAP on the brake booster extension and is next to the Cold Start relay.) The fuel pump and main relays each have 5 wires, but one could adapt the more usual 4 wire relays to work if replacements are hard to find. In my experience rapid clicking from the starter solenoid is a sign of a weak/bad battery; I've never heard other relays click rapidly with a battery issue, but who knows? HTH.
 

sfdon

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I'm getting a rapid clicking noise that seems to be coming from the ECU area - and my car ('72 3.0 CSi) is not starting. Dash light are showing, battery is showing full charge, starter motor is relatively new, Alternator is in decent shape and I'm running 123 ignition. Seems like it might be the ECU relay which looks pretty ancient and which I plan to replace. Just wondering if anyone's had a similar issue and what relay I should use in swop out?


You are saying it cranks but does not run?
 

TRIPPFONTAINE

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You are saying it cranks but does not run?
No, no cranking. I get full lights on dash and then rapid clicks ( that seemed to be coming from the ECU relay) but no firing and engine not turning over... The ecu activates the fuel pump so even without the fuel (dead ECU relay) I'd expect engine to turn over. Would a faulty ECU or dead ECU relay prevent engine from cranking?
 

sfdon

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There is a red wire coming from the battery that goes to the ignition switch

There is a another red wire at the 6:00 position on your starter. (Only on the djet engines!)


Thats all you need to know. That red wire at 6:00 position cranks your engine when you turn the key.

Forget about the ecu, forget about the relay.



Remove the red wire from its spade connector at the starter at 6:00.

Crimp a female spade connector onto a 2 meter long wire and connect it at the 6:00 position.
Strip a bit of insulation from the other end.
Tap it briefly onto the positive terminal of your battery.
The key does not need to be in the On or Run position. Leave the key out.
IF!! Your engine still doesn’t crank- Check ALL your ground and positive connectors to the battery and the engine/chassis AND remove all spark plugs and try again.

Please make sure your tranny is in neutral and parking brake on!
 

TRIPPFONTAINE

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There is a red wire coming from the battery that goes to the ignition switch

There is a another red wire at the 6:00 position on your starter. (Only on the djet engines!)


Thats all you need to know. That red wire at 6:00 position cranks your engine when you turn the key.

Forget about the ecu, forget about the relay.



Remove the red wire from its spade connector at the starter at 6:00.

Crimp a female spade connector onto a 2 meter long wire and connect it at the 6:00 position.
Strip a bit of insulation from the other end.
Tap it briefly onto the positive terminal of your battery.
The key does not need to be in the On or Run position. Leave the key out.
IF!! Your engine still doesn’t crank- Check ALL your ground and positive connectors to the battery and the engine/chassis AND remove all spark plugs and try again.

Please make sure your tranny is in neutral and parking brake on!
Thanks for that. I'll dust off the voltmeter and check for grounds then go under the dash. We're in a mega lockdown in Melbourne, so I can't say I don't have the time :)
 

sfdon

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Ummmm- no dash. No voltmeter. No checking for grounds (yet)

just a 2 meter piece of wire, a spade connector and a charged up battery.
 

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