E34 M5 died while driving

[1st 5er]

My wife called me and said;

Downshifted into second, went through the traffic light and before shifting into third noticed that the car had died suddenly.
There was no sputtering or other symptoms.
She coasted into a parking lot and it wouldn't restart.

I arrived and tried starting it to no avail.
It turns over fine and even fires off initially but immediately dies.
It shows 1/4 tank of fuel, but I added about 2 1/2 gallons, same symptoms.

Thoughts?

[mooseheadm5]

My guess is relay or fuel pump. Try jumping out the FP relay to see if you can hear the fuel pump running.

[Mark 88/M5 Houston]

Check and reseat the connector on the AFM.

[1st 5er]

My guess is relay or fuel pump. Try jumping out the FP relay to see if you can hear the fuel pump running.

That's what I was thinking, as was she.

Now, it's to the Bentley for locations. My E34 S38 OJT'ing has begun.

[1st 5er]

Check and reseat the connector on the AFM.

This I tried, as with several other connectors in the engine bay, along with the relays in the fuse box.

[mooseheadm5]

It may fire right up tomorrow. If so I would suspect either the crank sensor or fuel pump. BTW, the fuel pump is annoying to replace.

[1st 5er]

Today's diagnostics;

It didn't start right up.
I replaced the fuel pump relay with a known good one and it didn't start.
I jumpered #30 and #87 and the fuel pump sounded like a diesel engine, sorta.
With it jumpered, and sounding like it was about to fall apart, it fired right up.
Replaced the jumper wire with the relay and it fired up again, and again, and again, and...

Bottom line, bad fuel pump.

Next step is determining if I have the top or side feed model.
http://www.penskeparts.com/Diagrams/B00 ... =191028905

[mooseheadm5]

I replaced mine with a TRE pump (#6 style in your pic.) Works great and is quiet.

[1st 5er]

Mine turns out is the side feed.
For now, I'll just take the unit out of the '91 and install it in the '92.
I'll then replace the stock from the '92 with an after-market, possibly the TRE-340, if that would be the one, and use it as a back-up.

[1st 5er]

She's back on the road again, literally, rolling this time though.

Thanks Paul and Mark.

[Mark 88/M5 Houston]

Glad you got her back on the road.

[mooseheadm5]

Yup, I used the TRE 340 in mine.

[1st 5er]

That's what I'll get and throw it in the spare parts box.

[MShimon]

Yay, another M5 back on the road. Good work team.

[wkohler]

You're lucky you only had 1/4 tank of fuel in there. I had to replace a pump with a full tank. Ick. Then I wired it backwards thanks to two brown wires.

[mooseheadm5]

You're lucky you only had 1/4 tank of fuel in there. I had to replace a pump with a full tank. Ick. Then I wired it backwards thanks to two brown wires.

Almost the same here. I had to redo it because the "good" used pump someone at the shop gave me turned out to not be very good.