I just had finished replacing sending unit and intank pump, it ran good for 5 min several times while checking leaks, got my rough running stall after 30 sec cold, and may start once, but after that it will not run, just sputs, sputers, cranks fast, no start.

I thought, great new (used) prepump went bad, it still made noise at preignition, and during running, maybe it was bad. I pulled it out, put my prepump on the new sending unit, got the same result.

I must have coincidental failure.

My O2 sensor was my main culprit, I have 2.6ohms on the heater (good)
I have 12 volts on heatr supply line when the motor runs.
I have a fluke multimeter, digital, but not sure if it has 10meghome resistance recommended for checking the O2 sensor voltage. Does anybody know how to check the meter for that value?

I unplugged the O2 sensor, figured ecu was getting bad info from o2 and running car lean, it should at least run right----wrong--same results exactly.

I'm stumped, any ideas

Pre and main pump run during initial key turn, during run, and 1 sec after stall, it shouldn't be fuel pump relay?

Fuel pressure regulator was replaced 30k - 1 year ago. Pulled outlet hose, no raw gas. Seems like a rich problem, but it is consistant in the time to stall after a cold start.

My sender was rusted out, no running problems before surgery from that.