Fuel pump trouble

[Buffy]

I have replaced my fuel pump twice in the last 3 months last time it only lasted a day and burnt out, does anyone know why it keeps happening? I have an 89 316i euro spec

Sent from my SM-G950U1 using Tapatalk

[roguetoaster]

Intermittent/incorrect voltage (make sure the connector is seated properly/probe the connector when cranking), cheap fuel pumps (what are you buying?), debris in tank clogging the intake screen (inspect the inside of the tank), clogged fuel filter (replace)

Be sure to post questions like this in one of the technical forums in future.

[Buffy]

I bought a factory fuel pump the second time around, I hooked up a multimeter that read 11.5v when cranking, this last time I hooked it all up car started fine and drove home, tried starting the next day and the fuel pump wasnt turning on at all same thing happened last time I replaced it, could it be the relay even if the relay isnt burnt out?

Sent from my SM-G950U1 using Tapatalk

[Originale30]

I highly recommend replacement of the fuel pump relay with installation of a new pump, checking voltage is one thing but you’d need to do an amperage test to ensure the pumps not being overworked... my guess if the pumps keep burning out is that you have a clog or restriction in your fuel supply to the pump... is this the single pump in take design or the external 2-pump system you have on your vehicle?


Sent from my iPhone using Tapatalk

[Buffy]

Single in tank, and even if the relay looks like it's good it could be shorting it out? It doesn't happen when driving it happens when I go to start the car

Sent from my SM-G950U1 using Tapatalk

[Originale30]

Yes, I’d recommend replacement of relay


Sent from my iPhone using Tapatalk

[AndrewBird]

When the pimp died, did you check for power at the fuel pump connector? Perhaps it is an intermittent problem and changing the pump out gives it time to start working again, when the pump was never bad to start. Have you bench tested the pump?

A clogged fuel filter could be putting strain on it, but you would have runnability issues if that were the case.

Maybe a bad fuel pressure regulator that is making the pump work over time trying to keep up?

[Buffy]

So I tested the fuel pump and it still works, and the regulator isnt backed up, I'm going to test the relay terminals, and see if I wire the points directly if the pump will activate I've swapped relays with another one and it still didnt work, could it be the main relay in the set of 3 outside of the main fuze box

Sent from my SM-G950U1 using Tapatalk

[AndrewBird]

The relay only turns on for a few seconds when you turn on the key and then only when cranking. If your crank position sensor is bad, the ECU won't know the engine is turning and won't turn on the fuel pump.

[Buffy]

Okay, is there a way to bypass the crank sensor?

Sent from my SM-G950U1 using Tapatalk

[agent]

Be sure to post questions like this in one of the technical forums in future.

Yes.

Please do not ask technical questions in General Discussion. If you don't know where to ask your question, post it in General Technical and we'll move it to the appropriate subforum if necessary. Thanks in advance.

[AndrewBird]

Okay, is there a way to bypass the crank sensor?

Sent from my SM-G950U1 using Tapatalk

No. The ECU uses it for timing.