Starting problem

[thirdkid]

Have realized what the problem is. Fuel pump is not priming. But now i dont know why its not starting.

Have changed and used two different fuel pumps, changed ign switch, checked relays (im sure they were the right ones) and did line tests on relays.

I have blown first gear but im sure fuel pump is not connected to anything related to the box. Any help would be appreciated..

[jlevie]

Does the engine have spark when cranking? The fuel pump relay is controlled by the DME and is only energixed when the DME sees timing data from a rotating engine. If there is no spark, the DME doesn't have timing data or isn't running and thus the pump won't be turned on. In that case a bad main relay, bad CPS, bad fusible link, lack of a START signal to the DME, or a bad DME are all possibilities.

[thirdkid]

Sorry new to the bmw world. Where can i find the DME? Also with the CPS, if i take it off is it plug and play or like an RB nissan engine it has to be set at a right position? But wont the fuel pump prime once it gets power by putting the key into ACC? So before you spark the car the fuel pump should still prime wont it?

Last time i checked it had spark yes.

Thanks for the answer jlevie

[BMWLOCO]

Does the engine have spark when cranking? The fuel pump relay is controlled by the DME and is only energixed when the DME sees timing data from a rotating engine. If there is no spark, the DME doesn't have timing data or isn't running and thus the pump won't be turned on. In that case a bad main relay, bad CPS, bad fusible link, lack of a START signal to the DME, or a bad DME are all possibilities.

Jlevie, I'm having the same issues. Before there was no fuel coming to the fuel rail due to a bad fuel pump. Now I retrofitted a new Fuel Pump and I have fuel going to the rail, but none coming out from the Fuel Pressure Regulator. Any Ideas?

It cranks and cranks.. Got spark. etc..

Thanks in advance..

[jlevie]

Fuel to the rail but none returning from the FPR could be; a bad FPR, cogged filter, obstructed fuel line, or insufficient fuel pressure from the pump. Saying that you have "retrofitted a new Fuel Pump" makes me think that you didn't replace the pump with a BMW part, which could be the problem.

[BMWLOCO]

There is a thread that some E30 owners have put an Airtex fuel pump in place of the VDO with no issues. I'll check on the filters. I'm sure there is some sort of build-up of rust and gunk in the lines. Proof inside the tank when I drained the bad fuel.

Thanks again..