Another no start thread, yay

[jhaurimn]

1987 325i, stock m20

I know tons of these exist, and im going to look more into this tomorrow, but want to know if anyone has went through this same issue.

Car ran great for morths, now car wouldnt start as of a few weeks ago, realized that every time i tried to start the car, the fuel pump fuse would blow. I disconnected the in tank pump, and the fuse no longer would blow. Being an early model, i sucked it up and spent $300 on a new fuel pump.

Installed the new pump today, and the car still wont start.

If anyone has ran into this issue or has an idea of where i should start looking into, would appreciate the info.

[digger]

If it cranks check spark and fuel.

[jhaurimn]

So we have spark, but no fuel. Originally, the fuel pump fuse would not blow with in tank pump disconnected, but it still is blowing now when i jump the relay with it disconnected. All the wiring looks fine, so im starting to lean towards the external pump being bad.

[moatilliatta]

87's have 2 pump. Lift low pressure in tank and a High pressure external.

Did you put a generic pump in or a pump assembly? Wires switched? Does both the pumps make noise?

A bad fuel pump can put load on the fuse and relay, Id replace them if you haven't.

[e30austin]

I always change both pumps, at the same time, with new, OE parts - FWIW. You might have a look at the condition of the ground wiring harness, too.

[jhaurimn]

Ended up being the external pump. Should have known when the car wouldnt start over, since it can technically run on just the external alone. External pump was a URO part, so it was replaced since original but died likely in less than 40k miles. Stay away from that brand if you can (for fuel pumps at least).

I also checked/cleaned all terminals and inspected the wiring under rear seat, all good there.

Genuine bmw internal pump ($300...ouch) and a bosch external pump ($100) but we should be good for awhile now.