Fuel lines not pressurizing?

[Erick]

Car: 1985 BMW 318i

I havent had the time to look at the car myself but I'm asking on my friend's behalf. I cant make anything out of the symptoms that he described to me.

Car doesnt start, there is spark but no fuel, yet the fuel pump turns on (you can hear it on). It is a generic fuel pump that fit the 318i (external pump).

Any ideas or suggestions?
- Erick

[DEV0 E30]

If the 318i has an internal fuel pump when was it last changed? Fuel filter?

If you can hear it on, jump the fuel pump relay with a piece of wire to build up the fuel and pressure, (2 pins on the relay sockets) then try starting.

[lordofthewaters]

I'd jumper it, and remove a line just to see if it is pumping, just because it's making noise, doesn't mean it's pumping correctly. Then check the fuel filter. And also the fpr.

[Erick]

If the 318i has an internal fuel pump when was it last changed? Fuel filter?

If you can hear it on, jump the fuel pump relay with a piece of wire to build up the fuel and pressure, (2 pins on the relay sockets) then try starting.

I jumped the relay and I got no pressure still.

I have no idea when either was replaced but we'll start by replacing the fuel filter and reporting back with results.

- Erick

[Erick]

We replaced the fuel pressure regulator and nothing still. The lines never seem to pressurize.

Is there any way to test the internal pump? I dont want to purchase a new fuel pump without knowing if it's bad or not.

- Erick

[lordofthewaters]

Did you go to each pump and pull a line to see if any gas comes out? if it pushes gas out then it's working, if not the it isn't.

[Erick]

No gas gets to the external pump.... so I guess its the internal one then?

[lordofthewaters]

If you're going to invest in a new pump. I would go ahead and convert it to the newer single internal pump. It's easier to replace if you ever need too again, and it's cheaper to buy the one pump, than to buy an internal, and then maybe in a few months have to buy an external too.

[Erick]

Any info on that? Is it an easy upgrade or does it involve modification? What car can be a donor for that pump?

[lordofthewaters]

I think you can find something on it doing a search. As far a pumps go any one of the newer models should work fine I think.

[02stu]

yep sounds like your internal pump. If you want to save some money the chevy vega, I forgot which year, is the same pump. You'll have to attach it to your fuel pump assembly which is easy. Before you replace it though I would pull it out and connect it to your battery to see if it is alright. Your screen on the bottom of the pump might be all that is wrong. Have you run out of fuel recently?