E46 Fuel Pump - no power

[Cynogin]

Hi looking for advice and help. I have an E46 318ti. Car starts ok when cold but when it has run for a while struggles to start and has to cool down for a least 10 minutes. that was until yesterday. Yesterday i filled the car up to about 90% fuel, had strong fume smell and then all of a sudden the car would not start again. On inspection ...... fuel was leaking below the car ... it was coming from the top of the fuel pump under the rear seat. I cleaned up the petrol and the pump had no power coming to it. I checked both fuses in glove comp and in engine bay also checked and replace the fuel relay.

The relay does receive power from both the fuses when testing the relay sockets with a tester etc. however when the relay is put back in and i turn the key to position 2 the pump get no power. Key was re-coded and registers file.

any help would be appreciated and advice, thank you.

 

[Waseem 333i]

Run a wire from the pump to the battery. Make sure you secure the wire to the pump with a snug connector. Touch the other end to the battery. There may be a slight spark so please becareful. If the pump works then you have an electrical issue. I had a problem recently on a merc. There was no power coming to the pump. I checked everything only to find the pump was caput. When disconnected there was power. When connected there was no power.

Its also worth checking if the relay clicks to rule out signal issues

 

[Cynogin]

Run a wire from the pump to the battery. Make sure you secure the wire to the pump with a snug connector. Touch the other end to the battery. There may be a slight spark so please becareful. If the pump works then you have an electrical issue. I had a problem recently on a merc. There was no power coming to the pump. I checked everything only to find the pump was caput. When disconnected there was power. When connected there was no power.

Its also worth checking if the relay clicks to rule out signal issues

Hi Waseem. thanks for the reply. When i take a direct power source to the pump it works. Someone was telling me that it has to do with the starter or ignition. Apparently if the starters has an issue it wont activate the pump to receive power.... even when the engine cranks. I will have someone come out later today or tomorrow to have a look at it though.

i have swapped the relay with the horn relay, as both work when in the horn socket but no luck in fuel pump relay holder.

even did all the test in the link below. All work out positive except for when i put relay back and turn key to position 2 pump gets no power.
Thanks again.

https://www.bmwrepairguide.com/bmw-e46-fuel-pump-test-1998-2006-3-series-all-models/

 

[Waseem 333i]

It can be either wiring issues or immobiliser problem. For wiring check tis wiring diagrams. Immobiliser I have no idea how to resolve that.

 

[Tinuva]

It can be either wiring issues or immobiliser problem. For wiring check tis wiring diagrams. Immobiliser I have no idea how to resolve that.

Correct me if I am wrong, but the immobiliser prevents the starter from even engaging. It doesn't cut power to the fuel pumps. Its either the pump, wiring, fuses or something inbetween like the relay as mentioned earlier.

I know this because I went down a rabbit hole trying to figure out why the starter wont even make a peep when it turns out the autobox not reporting park when trying to start.

 

[Cynogin]

It can be either wiring issues or immobiliser problem. For wiring check tis wiring diagrams. Immobiliser I have no idea how to resolve that.

Correct me if I am wrong, but the immobiliser prevents the starter from even engaging. It doesn't cut power to the fuel pumps. Its either the pump, wiring, fuses or something inbetween like the relay as mentioned earlier.

I know this because I went down a rabbit hole trying to figure out why the starter wont even make a peep when it turns out the autobox not reporting park when trying to start.

This is one of those crazy problems.

i will revert back with some info once the mechanic has had a look and tested.

 

[individj]

haven't driven my 330i in 3 months...pump went...i put the M3s pump in it...drove fine..didnt start it for a month...now just swings...will deal with it 1 day haha. just gna take pump out and check.

 

[Cynogin]

so update on the fuel pump which was my actual concern............. just got a lot worse. The mechanic says that the car has no compression, swings to fast, timing chain/tensioner is done.
2020 has come with more than a fair share of problems

 

[Tinuva]

so update on the fuel pump which was my actual concern............. just got a lot worse. The mechanic says that the car has no compression, swings to fast, timing chain/tensioner is done.
2020 has come with more than a fair share of problems

Sorry to hear. Is this a 318 face-lift? On the N42 engine the tensioner is known to loose tension over time. When I had a 318 I replaced it before it became an issue. And while I have sold that car, I know its still running 100%

Sent from my Mi 9T using Tapatalk

 

[Cynogin]

so update on the fuel pump which was my actual concern............. just got  a lot worse. The mechanic says that the car has no compression, swings to fast, timing chain/tensioner is done.
2020 has come with more than a fair share of problems

Sorry to hear. Is this a 318 face-lift? On the N42 engine the tensioner is known to loose tension over time. When I had a 318 I replaced it before it became an issue. And while I have sold that car, I know its still running 100%

Sent from my Mi 9T using Tapatalk

---

318 TI 2003 model. Bought it in June 2020.
Already had the vanos replaced. This car takes
Money every month.

 

[gchipendo]

Hello Good people

I do not intend to hijack this thread, but happen to have an issue that seems related on my E46 2004 318i with an N42 engine. The car starts fine, after the temp gauge hits midway, if I switch it off I can not restart it until after about 20 mins. I have replaced CTS sensor, MAF, Fuel pump, FP relay and Main relay. Each time it fails to fire up, there is spark by the coils and fuel by the injectors which makes me think it's valvetronic related.

I need help finding a mechanic with proper tools who can diagnose this problem for me. I am in Joburg Selby.

Many Thanks!