Dilberto

I filled the tank up and it did not want to start.....taking several attempts, while pumping the gas pedal. Finally started but ran rough, until I throttled it hard, in Park. No code......and only 75,000 miles. Any guesses?

957 GTS

throwing this guess out there - faulty check valve?

Lexlthr

Same thing happend to a friend of mine. Turned out to be bad fuel pumps.

bfly

I just had the same issue. I was also getting a P0441 error code intermittently. Wound up replacing the tank vent. Part number 3 (94811020201) here: http://www.autoatlanta.com/porsche-p...section=107-00

mudman2

Yes the check valve and pipe, not a hard job but a bitch to get the pipe end off toward rear of engine.

There's a write up I did somewhere. maybe over on Renntech

bfly

Using a 90 degree miniature pick makes getting the hose off a lot easier. Just run it around the pipe, between the pipe and hose.

Dilberto

So, this part is a pintle valve, with hose? Part number?

PorscheTX928

Dilberto: I think I may be having a similar issue. How did you fix your issue? Was it the fuel pump or the valve?

I have an 08 Cayenne S, and I noticed after my car sat for about 2-3 weeks that it had a hard time starting. Battery is new and strong, and the starter churned away but would not fire up....it just kept turning the starter motor over, and not slowly, but very fast(normal)....I got scared and turned key off...and waited a few seconds and tried again and this time the car started normally. I thought it might be a fluke from having sat for awhile...but I went to start it today and it did the same thing...this time, the second time I tried, it did the same thing...it started the third try and ran a little rough until I pressed on gas pedal a few times.
Any help is appreciated. I know there is a procedure for testing fuel pump, and I will try that tomorrow. But the check valve mentioned in this post...is there a way to test it? It is 100.00 so I hate to start throwing money at the problem without first testing it. Thanks.

hahnmgh63

94811020201 Tank line Vent valve.

Max_O

Yup, probably the fuel tank vent valve. I just replaced mine and it is a common failure. Easy DIY.

Dilberto

Such a relief! No more embarrassing, gas station no-starts. And, what was the next part failure after the PV was replaced? Fuel filter flange was pissing raw gas away, while driving.

Note to Self: *It's still BETTER than my 2002 Audi allroad!!!!*

PorscheTX928

So I havent been driving the car because of the start up issue...but today...I decided to give it a go. Hard start (turns over nice and strong, but wont catch). It did start up the second time after 4-5 seconds. The car was idling roughly, and as I was driving, it was very sluggish, bogging down, especially when trying to accelerate rapidly. Check engine light came on...so I checked codes once home. Here is the list:

P0660 - intake manifold
P1023 - Fuel pressure high side
P1026 - Fuel high implausible
P0301 - misfire (1)
P0303 - misfire (3)
P0308 - misfire (8)
P0300 - random misfire
P1021 - fuel high pressure quantity.

cleared codes, and only the P0660 seems to be sticking around. I know the misfire codes are probably being caused by the actual problem...but searching forum for the other codes...seems the HP fuel pump seems to be a common issue too??? Is there a way to test the HP FP? I have checked and it seems the best price I could find for the pump is around 350.00...and it seems to be an easy DIY.

Dilberto

eBay has OEM HPFPs for under $300/shipped....

PorscheTX928

I have finally diagnosed my delay start / rough running issue as a bad HPFP(or primary pump). This looks like a pretty easy DIY project and although many recommend changing out both pumps, Im going to do just the left (driver side) main pump. To help those diagnosing in the future, I was able to narrow down the left pump by pulling fuses to test each pump. Very simple test to do.

Also, there is a fuel filter that can be changed at the time which costs from 70-120 depending on where you find it (Part#955 620 841 00). The part number for the HP fuel pump (Part#95562093101). It is an updated part number. Also, you will have to access BOTH fuel pumps to disconnect lines (thus the reasoning for replacing both), so you will need two new seal rings (95520113301). There is also a specialty tool recommended to loosen the pumps, but most seem to use the screwdriver/hammer method since the tool is around 75 bucks.

I have found a very good price on the fuel pump 229.99 - free shipping at FCP euro. The reason it is a good deal is that they offer a lifetime warranty on all parts - so this should be the last time you have to buy this part.

I will update once I get my new fuel pump installed....I will be driving around on the secondary fuel pump alone for now.

endless_corners

I drove for about a month and over a thousand miles on my secondary. You'll be fine just keep the tank level up.