What the heck!

[Jachenbach]

So I am sure I have my space reserved as being the biggest tool this site has ever seen. I have a 1992 525 wagon with transmission problems that morphed to afar that doesn't start. Short story checked fuel and ignition and the car ran after I removed the fuel pump, inspected and reinstalled. I thought I had the problem solved when I read that the fuel pump was a common source of ignition problems. I swapped the pump, no joy. Jumped the fuel pimp relay and the car ran fine. Stopped the car, replaced the relay and it started fine, ran for 10 minutes. Stopped the car, no joy. Jumped the relay confirmed fuel pump was running still no joy.

any ideas?

thank you for all your insight, Jim

[genphreak]

If using old pumps beware, they don't last out in the atmosphere for very long. New ones come sealed and should be installed in short order. I swapped a known good one out of an e34 535i, and within a few days put it in another 535i. After that it was totally dead. Beware- test and triple test your pump.

A lot of old e34 pumps die out with a whole load of intermittent failures- from what I've seen the '95 525iT especially- maybe they used a particular type of pump that dies slowly. Mine had a tall one; a Pierberg. I was chasing everything under the sun as it seemed to be working but in fact was intermittent and the variances in pressure upset mostly starting.