dutchcrunch

the 964 fuel pump does not prime on initial turn of the key like the earlier cars do. someone correct me if i'm wrong. our 964 fuel pums are commanded to come on when the flywheel speed sensor picks up a rated speed. your flywheel sensor might be the cause. but before you go replacing that you need to verify that your fuel pump check valve is functioning. you check fuel pressure running, and then verify the decay rate is within specs, ( example 50 psi for 20 miniutes with car off ) if the decay rate fails then its your fuel pump check valve that is replaceable on the pump itself.

k-works

Isn't there a somekind of a fuel pressure accumulator (like on CIS Mercedes?). This might be the case.

speedbagger

you're talking about 96462095100 (Retaining Valve), correct?

thanks--will look into this if the coils do not address.

dutchcrunch

96462095100 that's look correct.

dutchcrunch

I bought this from these guys, fits perfectly to our fuel rail and good deal.


http://www.arnnworx.com/catalog/inde...0#.VWdb7krD_cs

dutchcrunch

forgot what size ours is a 12 or 14 mm. I can check mine later and post. good tool to have.

sschultze09

Gents,
Thanks a lot for all of your great responses. Its going to take me a little time to go through them and try some diagnostics. But I really appreciate you guys throwing your experiences out there with this issue. On a side note I have always had to feather the gas peddle at take off when the clutch is released or the car dies due to the idle dropping (hot and cold) I do not believe I have a LWFW. The idle is good when the clutch depressed. Changing through the gears at speed the idle is not an issue.

HalV

Steve, if you need to swap some parts around to see if it makes a difference let me know. I have a scan tool, too, if you don't have one.

LPMM

Steve - Then look to see if your FPR is holding pressure. I had the same symptoms as above plus the starting one and it turned out my FPR was bad. I had it replaced and all issues went away, hopefully it is that simple.

sschultze09

Halv,
Thanks for the offer and Ill take you up on it if needed. We should get together anyway maybe C&C in Chan sometime this summer. I do have a scan tool and never really thought about doing an adaption. Will try that first.

sschultze09

Laurent,
The FPR is something I am unfamiliar with but a good possibility its the culprit. I guess its time to search this site. Anybody have a thread with this repair? BTY you still in MN?

HalV

Sounds good...let me know if you need anything.

I don't get down to C&C too often but I can try to make the next one. I'll be at the All Porsche Show in Roseville on the June 28, so maybe I'll see you there? How about you Laurent?

LPMM

Check the vaccum line that runs down to the fuel pressure regulator to see if it is connected properly and dry, as seen in this pic. If its damp with fuel inside at the regulator end, then the regulator is on its way out. All I know is that it is a pain to get to if you need to replace it, and I'll be happy to help out. Closest I could find is this thread but you'll find others if you do a search. And yes, still in MN.

I have not been to C&C and not sure I want to be near it, I hear from folks who go regularly that it has become quite the zoo. I will probably make it to the All Porsche Show if my daughter does not have a swim meet.
Also there is a 993 gathering in Long Lake on 6/9, right down the street from me. You guys are welcome to come to my home to shoot the **** and then we can crash their party.

NoSub Dan

DME relay.

964Lovac

So I’ve had similar issues as above.
Earlier this year I changed the following:
distributor caps and rotors
spark plugs
spark plug wires

all of this started after completing that work and changing out the rubber boots on my intake plenum. Car won’t start cold the first try. Will catch on 2nd sometimes or 3rd for sure. No other issues while driving, will start on first try after the initial start. So I’m stumped!

I’ve recently cleaned out my ISV And it hasn’t solved it either.

I pulled the vacuum line from FPR, no leaks.

appreciate any help!