Car dies, reset ecu and it runs perfect for few miles then dies??

[805eclipse]

I did search and found alot of possibilities but nothing that directly addresses my problem.

Ok so i was driving in 4th at about 50 and all the sudden there was no power.. the engine was running but i couldnt do anything but rev, it wouldnt go anywhere. and once i let the rpms drop it died and would not turn back on. the engine cranks fine but never starts.. first thing i decided to do was unplug the battery and reset the ecu, after that it started right up and ran as normal no problems.. got about 5 miles and it died again on the freeway. unplugged the battery again for about 10 min and it started right up and i went through this about 6 times and now i cant seem to get it to start even if i leave it unplugged for 30 min. happens while driving and at idle.

It runs perfect when it would start, confuses the hell out of me.

has brand new alternator, starter and ecu from motoguys garage. walbro 190 fuel pump, fairly new plugs and wires.

someone did replace the power transistor unit before i had it because the old one is still bolted to the car and the new one is just dangling but the connection seems good.

I had a spare known good ecu so i hooked that up and same thing happens, cranks but no start

couldnt test for spark or fuel ### i was alone and it got dark and i gave up.

any idea what the problem is and why it would run after resetting the ecu?


I would appreciate ANY input.. Thanks!

 

[Simadowna119]

are you getting any CELs? if so i would pull the ECU codes. could be something as simple as a fuel filter, maybe that big fuel pump pushes fuel through your clogged fuel filter and it runs for a few minutes, runs out of fuel and dies.. idk just an idea, look into the paower transister more... there is a vfaq on how to test the transistors.... i would do that since its been tampered with

 

[805eclipse]

no check engine lights and i replaced the fuel filter a month ago. im going to look into the power transistor and everything else more tomorrow. thanks

 

[SmoochDarling]

I would say its definitely the Power Transistor, they are relatively easy to test with a multimeter, it sounds like when the PT warms up it fails. I would look there first.

 

[805eclipse]

yep it was the power transistor unit. Thanks guys. resolved