Engine 93 Cobra loses spark>>>>

Monkeybutt2000

Mustang Master
Aug 11, 2019
1,280
840
123
Lafayette,IN
Owner (very close friend) has been battling this issue for over a year. Car will start and run for about 20secs,then die. With the key in the ON position, you pull a plug wire and put a plug in, it will NOT spark. You cycle the key back to OFF, the car will start,or throw spark at said plug EVERY time. If you pull the plug from the TFI module,and plug it back in, it will start or throw spark as well. There are no aftermarket electrical items hooked up to the car. We have tried two different ecu's, two different coils, and two different distributors. All three of these items were from my running,driving car so we know these parts are good. If you hook a dvm to the coil,and turn the car over,you can watch the voltage drop. We pulled codes as well, but IMO they wouldn't cause this issue. I can post those later if necessary. So,where do we begin?
 
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When you lose spark, do you also lose fuel injector pulse? Can you test with a noid light?

If not, I would troubleshoot the ECU relay, or just try swapping it if it's easier since you have a car to "borrow" one from. Not 100% sure this is a valid reason for your issues, but one thing to check out. It would be good to know if you are just losing spark, or losing injector pulse as well at the same time.
 
When you lose spark, do you also lose fuel injector pulse? Can you test with a noid light?

If not, I would troubleshoot the ECU relay, or just try swapping it if it's easier since you have a car to "borrow" one from. Not 100% sure this is a valid reason for your issues, but one thing to check out. It would be good to know if you are just losing spark, or losing injector pulse as well at the same time.
Gonna pick up a noid light,won't hurt to have it around. EEC relay was replaced with a parts store unit.
 
To me it doesn't seem like a part because you have replaced with known good ones.I believe it's a wire or wire connector.start with coil connector/wires.
 
If I solve it, can I have the cobra?

Seriously, I am curious if you lose injector pulse and spark at the same time. Could potentially narrow down where in the wiring the issue might lie.
 
An end to this thread. Buddy finally got the issue sorted out. He took the Cobra to Anderson Ford for a supercharger install and Holley termi X. They claimed the dizz wasn't seated all the way and made the computer shut the car down. He apparently had an oil pump drive shaft for a 351C.
 
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So,gang,I'd like to touch on this and hear some thoughts. The shop said it was the wrong oil pump shaft,which it was. However,how would the dizz not being seated all the way make the car shutoff? It has no way of knowing the installed height of the dizz. They claimed because the dizz was not locked down the timing was jumping back and forth causing the ecu to shut the car off.
 
My thoughts, since the 351 shaft does not fit into the 5.0 distributor hole it was riding on the end and slipping causing the distributor to stop/start turning and shut the car off.
My question is if it don't fit the distributor and fits the oil pump is the oil pump wrong?
Just thinking out loud.