Hello, first time posting here.

I've got a '90 Buick 3.3L V6 that belonged to my parents with 20K on it, not a typo! It'* used as a family backup vehicle. Back in '03 had a start/stall problem that ended up to a bad ECM which I understand was an issue for all GM about that time.

Two months ago, no start, dead battery. Installed a new battery and alternator which I believe was my fault.

Loaded out for a few weeks, back for a few weeks, out again for a week. While my nephew was driving it, started to idle rough, had to put it neutral to keep it running but finally died with a no start. Rescued by his father/mother but they returned to the car and with some Quick Sart managed to get it to my home. Used QS at the driveway, died half way into my garage and I pushed in the rest of the way.

Two days later, it starts right up like nothing happened! My AutoXray 6000 scanner captures show nothing different to captures made in 2003 about/after the ECM problem and no DTCs.

It was very humid that night with no wind and it does have all the OEM wiring, plugs, etc. I sprayed the wiring with a water mist, no problem. I went out after dark and did the same, no arcs or anything.

I hate to guess but I'll have to start doing something here but where to start? Anyone run into a similiar problem on any vehicle for that matter?

since you can start it with that stuff i would say your looking at a fuel issue, and i would start at the filter, after that maybe the pump or relay. i would check the power and grounds at the tank connector before replacing the pump though

I should have added a bit more info that I got from my brother-in-law who got it home to me.

He said that as long as he was on the throttle it would run. As he was trying to time traffic lights trying to avoid stopping, if he let up on the throttle or return to idle, it would feel it start to die. It appears that it wouldn't idle.

You might want to check the fuel pressure regulator. When it gets bad, it can cause similar symptoms

I have the Linder Tech Current Ramping 1-2-3, so I rewatched part but not all of the section on fuel pumps.

I just used a scope and current probe on the fuel pump feed at the relay, really easy to get at too. I could actually post the waveform but it doesn't look that bad compared to what I saw so far in the video. AllDataDIY lists pressure and 3500rpm for pump speed.

By knowing the amount of bars on the commutator(I emailed Linder Tech asking) one can figure the speed. Most are eight bars, if this pump is the same, it measures 3640rpm and drawing a max of 2.2A. Anbody know what a good '90 Buick pump draws.

I'm going to check the pressure next.

One thing mentioned in that video is one time on the east coast after refineries switched to winter blends, the weather tuned abnormally warm which caused no start problems. I think that this was just on older pumps. They did say that when the weather turned colder, the vehicles started right up.

I'm unsure of what blend of gas was in the tank but IIRC it'* winter blend and does make one wonder although it was driven a few weeks ago while on the same tank with no problems.

Have you checked the fuel pressure regulator?

No, that'* what I'm going to do next. Gotta find my MityVac, I believe that'* what I've used before on it.

It'* not the MityVac, must have another gauge setup somewhere.

It'* easier than that. Just pull the vacuum hose off the fuel pressure regulator and smell it for gas. If the vac hose smells like gas, replace the FPR.

Oh, you suspect a broken diaphram?

I'm going to follow the book since I found the my fuel pressure guage. You should have 41-47psi with KOEO, should drop 3-10psi with KOER and then put 14-16in of vacuum on the FPR to see if it'* bad or you lost vacuum.

If it'* the FP or the FPR, I find it odd that it wouldn't start without Quick Start one evening, two days later and ever since, it'* always started.