Pump relay only supplies power to the pump when you are cranking the engine to get it started and then for 3 seconds more. After that the fuel pump is powered through the oil pressure switch. You can pull the Pump Relay out and throw it in the trash after the engine is running and the engine will continue to run.
Try tapping on the ECM when it is running well. If the engine sputters badly you need an ecm, have seen this many times with GM ECM's of that era. Also tap on it when it is running badly and observe if there is any significant change in engine performance.
Also for that generation Vette there was a problem with wiring behind the cylinder heads and firewall, check this by shaking the wiring harness while it is running and observe for changes in performance
While it's running real bad unplug the vacuum to the EGR Valve to be certain it is not opening fully when going into "Closed Loop". ACTUALLY THIS WOULD BE THE FIRST THING I WOULD DO. Sorry for making it the last item of my short list.
|UPDATED|11/5/2015 12:26:07 PM (AZT)|/UPDATED|
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Track Day Rat
80 4Speed
96 LT4
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