in tank fuel pump not working - United Bimmer Community

**player2poet** · 01-05-2008, 11:36 PM

ok well i had today to do some last second trouble shooting on my car before i took it to the shop .now i dont know if this will fix my idle surging or not but my in tank fuel pump is shot does not turn on at all so im thinking that just might solve the problem if not it still needed to be replaced. i was reading that if the fuel pressure is just a little off this could alot of idle problems .i think i might of saved a trip to the shop although it still cost me $211.00 for the pump should be here on wensday.

**player2poet** · 01-07-2008, 05:03 PM

what do you think guys think in tank fuel pump can cause my idle to surge .im getting very worried that when i get the pump and put it in im giong to be disapointed when the idle freaks out. guess the next step would be to try a ecu from one of the other cars and see if that works i have pretty much replaced evreything else ?

**superj** · 01-09-2008, 05:33 PM

what is your exact problem? also, have you taken your pump out and cleaned it well with carb cleaner from the local store? spray it down and then hook it to the battery to see if it turns over. if not, then take the bottom screen off and spray it down again and try powering it again. it should come back as all the ones i ever did this to did. sometimes it took 15 or so minutes of cleaning it to get it working though

**mzbmw325i** · 01-10-2008, 11:47 AM

if the fuel pump is shot,how can you start the car, i mean doesnt the pump push the gas to the engine?

if the pump is making a high whiiiiiiiiine noise it is near its end life, i doubt cleaning will fix it, but you can try, that is one reason not to leave the tank to reach empty level, it heats up the pump thus shortening its life span and all the crap from the bottom gets sucked into it.

dont put gas from "unknown" gas stations, well gas in the usa is crap in general but a top tier station will have a better quality...i assume.

have you replaced your fuel filter also, general tune up, that might fix the idle issue, check for vacuum leaks, especially the boot going to the throttle and air box (MAF).

**player2poet** · 01-10-2008, 06:49 PM

I did all of thee above i can start the car becuse the main fuel pump out side the car is working .i replaced the in tank fuel pump becuse it was shot tried to clean it and start it sevral times .anyway it did not fix my idle problem ive replaced all vaccum lines intake boot ,throttle switch,icv,temp sensor,fpr,every thing but the ecu nothing car does not seem to idle well unless i bump them up to 1,100 rpms this car is not stock alot of things done before i got it that may have somthing to do with it. one is that the exhast is high performance three inch all the way back to magnaflow muffler stainless steel dinan headers .but i dont think that should effect the idle ,the head had been done before i got it that might be it valves may need adjusted .who knows at this piont ive tried just about all i can .giving up and taking it to a shop.

**Numark318i** · 01-10-2008, 10:30 PM

I replaced my fuel pump, fixed some problems. But my car still doesnt start everyonce in a while.

I have been told its my ECU.(by a BMW shop) The solders on these things arent all that high tech. They tend to crack. anything from weather or hard driving can cause it to not start.