Fuel pump working intermittently, do I need a new one?

[nadette]

So about a month ago I was experiencing a no start problem, got it towed to a mechanic, and for some odd reason it started up after that. While there had the CPS switched out. Car started up fine after that for a week or so, then one day I decided to pump gas. After filling up, I fired up the car and let it idle for a sec. A couple seconds later, the idle gets really rough and the car dies. I try starting again and it doesn't want to start. I wait about a minute and it starts up, so I give it some gas in neutral and drive off fine. The next morning it doesn't want to start up again.

I've been doing some tests and this is what I've found:

-No fuel pressure at all going to the engine when attempting to start
-Test light shows power at fuse 11 when starting
-Test light shows power at pin 30 on fuel pump relay
-Jumped 30 to 87 and still doesn't start
-Check the wiring harness to the fuel pump for power, two of three pins have power (assuming one is a ground)

Is it safe to say that I just need a new fuel pump, or are the more tests I should be doing?

1991 325i

[jlevie]

You should see power on one of the two pins of the pump connector but not the other. The three pin connector is for the fuel level sensor. Check pump power with the pump connected. And use a voltmeter, not a test light.

[nadette]

Don't have access to a voltmeter at the moment.

If I'm not getting any power from either of the two pins with a test light in there when trying to start, is it possible that I have a wiring problem?

[jlevie]

If the test light shows power on both sides of fuse 11 when cranking, but not at the pump, you have a wiring problem.