Still dies... need help to inventory plan of attack

[BigD]

Alrighty, changed the fuel pumps, they were definitely affecting the power. The car now pulls as expected of an E30 with a 3.2 but it died on me again. This time it wouldn't restart after cranking. I tried a few times later and it farted a few times but that's it. I'm also running no pump cover or back seat to check for leaks after the fresh pump replace and the pumps make 0 noise.

Should the pump be running with ignition on but engine not running? I don't think I've ever had that. Sometimes I would turn the ignition to on and I'd hear the pump run for a few seconds. But rarely. Should this happen every time?

One thing I found while snooping around the engine bay on the side of the road is the little wire (fusible link?) running to the battery junction with the main battery lead was loose (not off but totally loose on the stud). I tightened the nut but it didn't fix the problem.

All electronics are fine. It cranks, it shows the check engine on when I turn ignition on, I can hear the relays click when turning ignition on (don't know yet if the fuel pump relay goes on... but again I hear nothing from the pumps, which are both new as of yesterday).

I need your input for the plan of attack for the weekend, here is what it is currently:

1) Fuel pump relay - which one is it? I have a yellow, white and blue. The yellow has huge mother wires, so that's main...

2) Fusible link (wtf does this do exactly?)

3) Anything else?

[BigD]

PS: Pushing an E30 with sticky tires and too much toe out for a quarter mile SUCKS.

[BigD]

Doesn't look like the pump relay. I jumped it and the pumps ran fine. Tried starting, still nothing. So now it's either ignition or injection...

The DME "seems" ok, it shows the check engine on ignition on, and I can read codes - gives 1444.

Pulled out a plug and it's bone dry, no smell of fuel.

Injectors have power... gonna try to check if they get triggered.

Any suggestions?

Thanks,
D

[BigD]

Fuck I dunno. Gonna recruit some help from my dad to see what it's NOT doing at least... I rigged up a test light out of a map light bulb. I didn't see anything on the injectors but I fear the pulses are too short to heat up the filament enough for me to see anything, will check it out on an oscilloscope. Also need his help to watch the spark to see if it's getting any of that.

It's just such a weird behavior, seems electrical in nature. It died in the same fashion as before, except this time I did a whole bunch of WOT pulls, thankfully the "last one" was close to home. This time it didn't stumble and die during but right after. Took it up in 2nd gear, up into 3rd, trying to drive normally, not much throttle response, dying, dying, dash lights up, dead. Waited a bit, tried to restart like last time and it actually DID sorta fart and start but then died again. During my rest breaks while pushing the car, I tried starting it a few times again, and one time it fired a little. No sign of life since then...

[BigD]

I'll continue talking to myself... just rigged up a coil with a plug and I do have spark... So all that's left is fuel... why the hell would the injectors not be firing if the coils are... I just hope I see that because if I don't then I have a fuel line clog (can't be a kink, it was running like a beast all day yesterday), because I've run the fuel pumps with a jumper and they both run perfectly fine.

[justin_l_]

When is the last time the fuel filter was changed?

[BigD]

When is the last time the fuel filter was changed?

2 days ago, along with both of the fuel pumps, which run great.

[hoveringuy]

Fuel injector ground?

Internally collapsed fuel line? I've seen them deteriorate and slough a piece off that blocks flow.

Hoveringuy

[PiercedE30]

Break out the o-scope and see what the injectors are doing. That and pull the fuel feed line and make sure it is flowing fuel.

[BigD]

Short story: frustration leads to trouble

Long story: it was the fucking fuel pump. The scope showed the injectors firing nice and evenly, so no fuel. I started thinking ok the car's done for the year until I change out all fuel lines. But then I recalled how hard it was to put in the in-tank pump yesterday - it drove me insane. To make matters worse, taking it out and trying the old pump, it dropped in exactly as expected, turn it a bit counterclockwise, drops into the teeth, turn clockwise, locked, done. But the new one wouldn't drop into the cutout, I couldn't turn it counterclockwise enough. I could feel it hitting something inside the tank. Finally I diluded myself into thinking that it's the new O ring, pushed harder, I felt it give, turned locked done.

Pulled it out today after eliminating all else (other than fuel lines) and the "give" was the inner metal pipe bending (the small one), which offset the pump and pinched the rubber hose shut (that connects the pump to the outlet pipe).

I inspected the pumps closely and that rectangular plastic filter foot, is turned a few degrees counterclockwise compared to the old pump - just enough to prevent it from turning to go into the slots....

If I can exchange the new pump I'll put in a new but my "old" pump looked good and works great, I think the outboard and filter were my original problems, those were pieces of shit. At least now I know how the engine should sound with the pumps running - before with the kinked pump I heard no fuel rushing in the injector rail...

It's back to being it's gloriously loud and fast self.

[MIKe30]

damn, I was at post 4 and i was sure it was the fuel pump. The symptons (the way it died, and ESPECIALLY the way it would sorta start up but not really sometimes) were exactly the same as my m50 car was when the fuel pump died on it. Anyway, hindsight is 20/20, and i wouldn't have known you bent pipes!

Glad to hear its running nice again. You put a stock pump back in or upgrade?

[BigD]

damn, I was at post 4 and i was sure it was the fuel pump. The symptons (the way it died, and ESPECIALLY the way it would sorta start up but not really sometimes) were exactly the same as my m50 car was when the fuel pump died on it. Anyway, hindsight is 20/20, and i wouldn't have known you bent pipes!

Glad to hear its running nice again. You put a stock pump back in or upgrade?

I agree, this is the way it acted initially and I replaced the fuel pumps yesterday, so fuel supply, short of a suddenly clogged line, was the furthest thing from my mind.

In retrospect this is a good thing. I found two bugs that I fixed - the loose power wire and my ICV wasn't all the way in.

I put stock pumps in, I like the dual pump design. If I keep the car long enough for the outboard to die again, I'll go for a Walbro.