E30 wont pump gas

[Frederikplam 0]

I got a e30 that won’t pump gas thru.

it only got 1 pump (the one under the car)

I changed the pump and you can hear it running when you turn the key.

all the fuel lines are new.

can it be real that I only got that one pump and not one in the tank. 

the only thing in the tank is the fuel sending unit which I can’t find a new one of anywhere.

that why am wondering if it’s a aftermarket one that’s been replaced by the original pump.

what should I try next???

[deedub 32]

I'm still pretty new to E30s. Someone who actually knows these cars could confirm.

But according to the Bentley service manual 84-87 models should have an electric transfer pump mounted in the fuel tank (haven't actually touched the fuel system yet so I'm just going off what the manual tells me).

Apparently on 88-90 models there's only a main fuel pump and that's mounted in the fuel tank.

So based on that, you shouldn't only have a sending unit in there.

Have you ever been able to drive it? Was it running prior to changing pump?

[deedub 32]

Because you have a fuel pump under the car then I'm guessing you have an 84-87 model and should have an electric transfer pump in the fuel tank.

[Frederikplam 0]

Its a 86 model 4 Doors and i bought it like this, so i never had it started.

Can i just buy and original gas pump and put it in the tank???

its just weird because the plug with the power too the “original pump” isn’t there (if it’s actually missing the pump).

and the even weirder part is that I’ve seen the exact same system on an model 83 coupe. With the same wiring, plug and sending unit. Just without the return hose (that I got)

 

 

[deedub 32]

Have you checked out realoem? Put in your vin and confirm what was there originally for your car. Then you can search for that part online or go to a pick a part/wreckers maybe.

This might be what you're looking for? (but confirm first through realoem).

[E30 325i Rag-Top 2956]

13 hours ago, Frederikplam said:

the only thing in the tank is the fuel sending unit which I can’t find a new one of anywhere.

Post up a picture of this, on early E30s the in tank pump and the fuel sender are on the same frame.

[Frederikplam 0]

I’ll put a picture in later.

[Frederikplam 0]

It’s exactly the same as this one, but with a fuel return on too.

and that’s the only thing in the fuel tank

[Frederikplam 0]

This is the setup i got, so it is original.

its number 7 i have in it.

but doesn’t have number 10 and 11

why isnt it pumping gas then????

its so weird

[e30ftw 410]

That is the lift pump. It feeds the external pump and reads tank level. Either it's dead or the plugs missing as you mention there wasn't a plug..

Item 10 and 11 is the newer revision which is the in tank pump and fuel level sender, separate units, on a cradle.

I'm pretty sure if you get a cradle you can switch to the newer style and use in tank fuel pump instead of the lift pump and external. You will need to do some wiring though.

Edited September 19 by e30ftw

[Frederikplam 0]

Okay, so that does “pump” fuel up the tank and too the next pump??

because that thing does not work, because one of the wires inside has fallen of.

but I’ll try fix that then, thanks!! 
I just thought it was only a tank level reader

 

[Frederikplam 0]

Now I have put it all together and renovated the sending unit. So it gets the power it need.

but it’s still not pumping any gas out the tank!!!

[Frederikplam 0]

And the only thing I get out off the sending unit is a 5v signal so am still pretty sure it’s just a fuel level reader and not a pump in any way

[e30ftw 410]

Yes the lift pump is just to prime the external pump and is only a very low pressure pump. I don't know if it's supposed to be 5V though. Have you tried bench testing it with 12V?

 

[Frederikplam 0]

No i have not.

have do i do that??

[beemwr 46]

Don't try this at home, unless someone confirms that u won't do any harm to yourself or the pump' but to 'bench test with a 12volt battery checking red & black match up.

Don't shoot me, did same with my external surge tank pump. It didn't pump or make a pump working sound so ordered another.

We all have to learn the right fromwrong as we go.

Edited September 24 by beemwr
Meant a 12v battery, not chrger won't do job