1991 Z28 LB9. All original, car starts up just fine when cold.

But once running for a short while the car just quits. Have 42lbs of fuel pressure. Have spark to the plugs. However, the injector pulse quits out of nowhere. Wont start back up for a few hours until it cools down.

What can cause the ecm to be told to stop firing injectors?

Thanks.

 

My four most likely suspects , in no particular order , would be ;

Bad injectors that have OK resistance when cold , but get lower resistance when hot , dragging down the injector pulse . An ohm check of the injectors both cold and warm will tell if this is the case .

Bad ICM getting hot & not sending the distributor reference pulse to the ECM (even though it's still making spark the reference pulse still could be going MIA) .

Bad ECM .

Bad electrical connection to or from the ECM that gets hot and goes open circuit .

 

My guess would be the ICM.

GD