Hard start on my 2004 M45-sputters and stalls

[jbradner]

When I turn the key on in my car, it will prime the pump (Which seems to take a while, 3-5 sec.) the relay will click under the dash and the car will start just fine. If I just jump in and turn the key to start, the car will sputter and sometimes stall for the first 10 seconds or so. Any idea if this is a fuel pump issue? The car has 63k on it and as far as I know, the fuel pump is original and the fuel filter has never been replaced. I'm just wondering what could be causing that. It seems to run fine when its running.

[loystock]

If you have to prime it to start the car, most likely problem is in the delivery side. Hopefully, it's just a dirty filter(@ $11) but it could also be the fuel pump (@ $300) or fuel pressure regulator. The fuel filter is housed together with the fuel pump and regulator inside the fuel tank. Ensure fuel pressure is released and battery is disconnected before doing any servicing. Always replace the o-ring anytime you pull out the fuel pump and filter assembly. Below is the link to IoS for fuel system component pricing info.

http://www.infinitipartsusa.co...gid=0

[jbradner]

Thanks, I have been stranded before with bad fuel pumps so I figure for the money, I may as well replace it as well. What O-ring are you talking about by the way? The one that seals the pump into the tank or is there one on the pump itself?

[debiniarthug]

This has happened to me. Sputtered then stopped. It happened after getting the injectors cleaned and fliuds flushed. The next day after getting it towed to the dealer, it startes right up and I never had the problem again. That was two years ago.

[SteveTheTech]

Going off ASE test logic a restricted fuel filter should be more noticeable as a loss of power under acceleration whenever the injector pulse was longest. However we all know crazy things do happen.

The first question I have is does the car ever stay running?

I would guess a dirty MAF, if it actually catches and stalls. If it doesn't I would say the key. However you might want to start by checking for codes and performing the idle volume learning (if you can it running).Reason being open loop (cold start) operation requires every input and output to work perfectly, and since everything happens in a fraction of a second there is no time to correct and the car will stall.