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E46 Fuel Pump

48K views 45 replies 26 participants last post by  Kittepunch 
#1 · (Edited)
I'm new to this forum, I just got this E46 and this is the first time trying to fix it myself, I would like to know if any of you guys have had trouble with the fuel Pump, If so I would like to know how to know if is broken? Thank you.

The car cranks but won't start and the i let it seat for about 4hr and it will start again, I need help trying to Diagnos it.
 
#6 ·
It could be your fuel filter only being clogged. Happened to me also...Was in traffic and the car just shut off. Tried to start it but the car would not stay on, or would not let me rev it...and cut out after a few seconds. When they towed the car to the dealership a few hours later, it started just fine.

Basically, from what was explained to me...because the fuel filter is clogged, it could not pass fuel to the side of the tank where the pump is...

Fuel filter replacement is done on each inspection I, I think, or II. haha
 
#10 · (Edited)
fuel related problems will not set any faults in the DME on the e46 . i would check fuel pressure at iddle , and then while driving ( under load ) . If you do have a pump problem you should replace the filter as well .
 
#8 ·
I had my fuel pump die on me while on the highway. Had merge over 3 lanes of traffic to get to the shoulder with no power.

Sure way to test is to look at your fuel rail. There's a small valve towards the front, if you press it with a small tipped screwdriver, fuel should come out. In my case, I heard AIR.

I'll have to agree with checking your fuel filter (under the belly, driver's side). Go ahead and check your fuel lines (especially going towards the front of the vehicle). Any kinks is sure to restrict fuel flow.
 
#9 ·
Just replaced the fuel pump on my daughter's car 2 months ago. Problem was intermittent, it stalls and not start. After a few hours, it will start again. One way to check if the fuel pump is the culprit is to listen for the sound. When you turn the key on (without starting engine), you should hear the pump run for a few seconds. If you can't hear any sound, more than likely the pump is broke. Another test is to lift the rear seat to gain access to the pump (passenger side). Tap the fuel pump with a rubber mallet then try starting the car. If it starts, then 100% you need a new fuel pump. Good luck!
 
#11 ·
i dont know were you learned your diag techniques but these aint our fathers 69 Camaro . The fuel system is more complex than that . for example If you have a siphen pump problem ( wich is the left side sending unit that feeds fuel to the right ) you can have these problems listed above , fuel pump could be good but starving it self becasue of a faulty siphen pump . dont just throw parts at the car unless its an ovious problem , dignose the problem right and fix it first the first time . :thumbsup:
 
#16 · (Edited)
#19 ·
take off the plastic cover beside the valve cover that covers the injectors, and on the fuel line you will see a valve, inside it is a schrader valve like on tires. u can remove that schrader valve, put a hose on it going into a bottle or something and turn the key on and see if you have any fuel pressure
 
#22 ·
CHANGE OUT YOUR FUEL PUMP RELAY LOCATED BEHIND THE GLOVE!! DON"T MAKE THE MISTAKE LIKE I DID AND WASTE MONEY CHANGING OUT THE FUEL PUMP AND FUEL FILTER WHEN ALL IT TOOK WAS A 8 DOLLAR RELAY. My car wouldn't start in the early morning but after sitting out in the sun for a few hours it fired up all the time. But when it started getting dark my car wouldn't start (no, its not a solar powered car, hahaha) This is what you should do. Sit in your car (driver side duh!) and keep your door opened. Turn your key to the 2nd on position. You should hear a hissing sound from under the car. If it hisses then turn the key all the way to fire it up. If you don't hear anything turn the key off, wait a few seconds and try again. Some mornings I had to turn my key 10 times before i would hear the hissing sound to start. After replacing my relay, I took it apart and to examined it and sure enough the metal solder looking thing was warn down to where it couldn't get a good connection when it tries clicks on due to cold weather ( I had my problem in the winter time). PM if you have any questions. Again if you're gonna try and trouble shoot your problem, always start with the easiest and cheapest part first b4 you start throwing your money away.
 
#26 ·
pump

cant be sure what yours is mate, but turn key in ignition, listen for pump. then tap with mallet, usually it would try and function but dosnt keep enough pressure to keep car running if it does start, after i replaced mine there, it runs sweet, dont drive your car until you get it sorted, because when the pump goes, it goes, and you will be stranded!! mine stopped working 1st time in driveway, didnt move until i got new pump...fingers crossed thats it now!!
 
#27 ·
Help needed my 2004 325 will not start due to an accident i had that oppend my air bags. Can the minor accident stop the fuel for not geting to the motor?? Is there a recet somewhere for a fuel pump or anything that controles the eng to not to start because of the accident??
 
#29 ·
^exactly. in more serious collisions the Battery Safety Terminal is triggered. it severs the starter cable from the battery so you don't get an electrical fire. your warning flashers, interior lights and power windows will still operate.
 
#30 ·
Looks like I have the same problem. My car started up and ran rough for about 10 seconds, then stalled and I could not start it. I was getting nervous and tried a bunch of things that did not work, but finally I reached under the car (passenger side under the rear seat) and slapped the fuel tank a couple times. I started the car and it fired right up and ran fine. Unfortunately, a few days later it did it again and I did the same thing and it started right up. I want to get to the bottom of this before I get stranded somewhere. Is it the fuel pump, the siphon pump, or something else? BTW, I replaced my fuel filter a few months ago and don't think it's the problem.
 
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