Starting Problem

[rogerjohnsen]

I decided to have the car towed back to the shop that did the original repair so they could do a pressure test.  I just received a call from them informing me I'm in need of a new fuel pump.  Does this sound right?

[Ahsai]

That fits the symptoms but it's quite a coincidence that you had the fuel pump failed right after the crank position sensor failure... could the crank position sensor be a misdiagnosis? I guess you'll never find out..

Edited March 9, 2015 by Ahsai

[JFP in PA]

I decided to have the car towed back to the shop that did the original repair so they could do a pressure test.  I just received a call from them informing me I'm in need of a new fuel pump.  Does this sound right?

 

If they tested the fuel system and got low pressure and/or delivery, I'm afraid the answer would be yes.

[JFP in PA]

That fits the symptoms but it's quite a coincidence that you had the fuel pump failed right after the crank position sensor failure... could the crank position sensor be a misdiagnosis? I guess you'll never find out..

 

This is why the should both be tested in tandem; a bad CPS would also give you no fuel pressure, but if you then jumper the fuel pump at the relay panel, the pump should run, even with a bad, or no CPS.

[Ahsai]

 

That fits the symptoms but it's quite a coincidence that you had the fuel pump failed right after the crank position sensor failure... could the crank position sensor be a misdiagnosis? I guess you'll never find out..

 

This is why the should both be tested in tandem; a bad CPS would also give you no fuel pressure, but if you then jumper the fuel pump at the relay panel, the pump should run, even with a bad, or no CPS.

 

Yeah, maybe the shop just stopped there after they found a bad CPS....would be interesting to ask the shop exactly what tests they performed on each visit.

[rogerjohnsen]

It's possible the CPS wasn't the culprit in the first place as I never was able to actually test it and the shop didn't save the old part.  I was just elated to hear it fixed the problem so not sure why it worked.  (Short lived in any event...)

 

Anyway - I thank you gentlemen for your assistance with this and will keep you posted.  Just got the new fuel pump ordered so should have the car back in a few days.

 

Side note question - Assuming the fuel pump pressure was low, could this explain the car not seeming to have the same power as when I first got it?  I have a lot of fast vehicles so thought maybe it's just me.  I guess I'll find out soon enough but curious in the interim.

[JFP in PA]

It's possible the CPS wasn't the culprit in the first place as I never was able to actually test it and the shop didn't save the old part.  I was just elated to hear it fixed the problem so not sure why it worked.  (Short lived in any event...)

 

Anyway - I thank you gentlemen for your assistance with this and will keep you posted.  Just got the new fuel pump ordered so should have the car back in a few days.

 

Side note question - Assuming the fuel pump pressure was low, could this explain the car not seeming to have the same power as when I first got it?  I have a lot of fast vehicles so thought maybe it's just me.  I guess I'll find out soon enough but curious in the interim.

 

Low fuel pressure or volume delivery will definitely make the car run soft.

[JFP in PA]

An additional thought:  A 2004 996 Turbo has an external fuel filter (part #  996-110-253-52); when was the last time yours was changed?  I would also suggest that if you are going to replace the pump, put a new fuel filter on it as well.

[rogerjohnsen]

An additional thought: A 2004 996 Turbo has an external fuel filter (part # 996-110-253-52); when was the last time yours was changed? I would also suggest that if you are going to replace the pump, put a new fuel filter on it as well.

Good to know and I'll ask them to make sure they replace that filter as well. Thank you for this. You don't think this would be the problem do you?

Edited March 9, 2015 by rogerjohnsen

[JFP in PA]

 

An additional thought: A 2004 996 Turbo has an external fuel filter (part # 996-110-253-52); when was the last time yours was changed? I would also suggest that if you are going to replace the pump, put a new fuel filter on it as well.

Good to know and I'll ask them to make sure they replace that filter as well. Thank you for this. You don't think this would be the problem do you?

 

 

Without seeing the filter out of the car, it is hard to tell; but clogged fuel filters can and will act like a dying fuel pump at times.

[rogerjohnsen]

Unbelievable!!!  I got my car back today and I can hardly believe it.  The fuel pump has been replaced and a fresh oil change and WOW!  All I can think is the fuel pump has been on its way out for some time now as the car hasn't performed this well in years.  I think I mentioned earlier the car didn't feel as fast as I remembered it and that was definitely the case - it's back up in my favorite car list...

 

Thank you gentlemen for your guidance in working out what the problem was.  The mechanic still thought it was strange it started working after replacing the CPS but clearly this was a fuel pump issue.  I had brought the lack of power issue up at the dealership (2 separate ones) and was told by both I needed to clean the fuel injectors.  I've put nearly a case of Techroline in the car over the years but it never seemed to make any noticeable difference.  The mechanic / shop owner who worked on the car told me to drive the car more often and that gas sitting in the tank starts to become acidic in as little as a week. I've always used premium gasoline (Chevron or Shell) but didn't realize the fuel could start to go bad so quickly.  I was told this is likely the reason the fuel pump failed. 

 

:drive:

[JFP in PA]

Unbelievable!!!  I got my car back today and I can hardly believe it.  The fuel pump has been replaced and a fresh oil change and WOW!  All I can think is the fuel pump has been on its way out for some time now as the car hasn't performed this well in years.  I think I mentioned earlier the car didn't feel as fast as I remembered it and that was definitely the case - it's back up in my favorite car list...

 

Thank you gentlemen for your guidance in working out what the problem was.  The mechanic still thought it was strange it started working after replacing the CPS but clearly this was a fuel pump issue.  I had brought the lack of power issue up at the dealership (2 separate ones) and was told by both I needed to clean the fuel injectors.  I've put nearly a case of Techroline in the car over the years but it never seemed to make any noticeable difference.  The mechanic / shop owner who worked on the car told me to drive the car more often and that gas sitting in the tank starts to become acidic in as little as a week. I've always used premium gasoline (Chevron or Shell) but didn't realize the fuel could start to go bad so quickly.  I was told this is likely the reason the fuel pump failed. 

 

:drive:

 

Current fuel blends, particularly with 10% ethanol in them, can degrade pretty quickly.  StaBil makes inexpensive additives that can stabilize ethanol blended fuels for up to two years.  Worth a look, we use their "Storage" product on all vehicles put up for the winter here, and have never had one act up in the spring.