I agree with the reasoning provided to this point including beegeezy's. I think we can take it even 1 step further knowing that unplugging the airflow sensor (MAF) kept the pump and the car running. If crank/cam /run signal to ECU was dropping out or B+ voltage into MFI at pin 7 was lost, or MFI was bad and opening the circuit after only seconds,the car would shut down despite the MAF being unplugged...that didn't happen. So the ECU logic and/or some circuitry components failing is the branch point as to whether it gets ground to pin 8 W-R or not to keep the pump running. Confirmation done by seeing if ground suddenly lost on W-R at ECU end or MFI end. Pull ECU and post some good up close pics if that's happening.From the test results of the MFI relay, it sounds like at least a defective MFI relay at this point. You can also check to see if the ground signal from the ECU (I think it’s a white/red wire IIRC) also drops. That ground signal is what activates the MFI relay as seen here:
Note: I think the wiring pins at the MFI relay are numbered differently on the 1G cars. But you’re still looking for the ground from pin 8, I believe.
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