Confirm my suspission...engine dies

[Beej '86 325es]

I picked 'er up from the exhaust shop this week. It ran fine when I dropped it off, but when I picked it up, I couldn't keep it running for more than 15 seconds, having to give it a lot of gas to keep it running even for that long. Each time I restarted it, it would run for shorter and shorter periods. By the end, it would only fire a couple of cylinders.

I'm thinking it's got to be fuel delivery related. Could a bad fuel pump relay cause this?

Thanks

[lifeiskaos]

lol. sounds like when i blew the pistons rings in my m20 turbo

[Uber E30]

i bet they fucked up your O2 sensor

[M-technik-3]

Try disconnecting the o2 sensor.

[Beej '86 325es]

Actually the O2 sensor still hasn't been hooked up. That was a nice little surprise when they forgot to do that portion of the work.

[sushipower]

Sounds like it's your fuel pump. Can you hear it when cranking engine? Take off your fuel line at fuel rail and give it a quick crank. GL

[BigD]

I dunno guys giving more gas shouldn't keep a car with low fuel pressure running - it should make it die faster. If the pump can't supply enough fuel at idle, it surely won't be able to supply at more throttle (air).

At best I'd guess it's a vacuum leak that's getting worse, like a loose ICV hose, which is slowly falling out more and more. That way I could see more throttle making it run longer when the leak isn't too bad - the unmetered air would make it effectively less lean at more throttle.


What follows is a bit of fear mongering so you may want to choose to not continue reading...



What you describe is how my S38 died when the chain skipped due to a dying oil pump (the chain tensioner on those is hydraulic). First it started running weak, but giving more gas made it almost fine. Then it was less and less powerful, then it was hard to start and didn't run for long, and finally it wouldn't start. Like you I thought it was a dying fuel pump or something so I kept trying...

[SamE30e]

Maybe they didn't unplug the ground when they welded.

[Beej '86 325es]

Sounds like it's your fuel pump. Can you hear it when cranking engine? Take off your fuel line at fuel rail and give it a quick crank. GL

I'll check if the pump is running tonight.

Maybe they didn't unplug the ground when they welded.

I think they did, because the negative battery terminal was loose when I picked it up.

[Beej '86 325es]

Replaced fuel pump relay, no avail.
Checked for spark, all good. I can smell fuel out the tailpipes though.
I THINK the fuel pump is pumping. Tomorrow I'll try checking for fuel pressure at the rail...running on 3 hours sleep today from the Aerosmith concert! :(

[M-technik-3]

OT but how are the old guys performing these days?

[Beej '86 325es]

pretty good actually, they still get the crowd going. Unfortunately they played mostly new songs that nobody knew. It was at an outdoor amphitheater and we had some severe storms in the area. They delayed the concert until about 11, and then we stood in the rain for another couple of hours...

[416stroker]

Coilpacks everything I've heard they just can fail one after another

[surebimmer]

Make sure the ICV tube is locked into the manifold. When I started my car it backfired through the intake and blew out the ICV hose under the intake and the car would start and run like crap, large vacuum leak. Locked the ICV hose back in place after i found it and run's great.

[Beej '86 325es]

Make sure the ICV tube is locked into the manifold. When I started my car it backfired through the intake and blew out the ICV hose under the intake and the car would start and run like crap, large vacuum leak. Locked the ICV hose back in place after i found it and run's great.

Thanks, I'll check tonight