Greetings from Portland

[Luckyman01]

I had the same problem, while there can be a number of reasons, in my case I eventually found it to be a bad vacuum hose from the intake to the fuel pressure sensor on the fuel rail.

Viewed from the back on engine compartment, it is on the fuel rail, left upper corner.
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Hopefully this will help and you can avoid the throw parts at it path I went down.

David

[Luckyman01]

Porsche Beaverton, still Sunset Porsche to me has online part sales at very completive prices, shipping can be a little high.

[LoneWolfGal]

Originally Posted by Luckyman01

Porsche Beaverton, still Sunset Porsche to me has online part sales at very completive prices, shipping can be a little high.

I bought a very nice pair of rubber floormats that have the Porsche logo from Sunset for $89. I've been spoiled by Amazon Prime, so any shipping charge seems exorbitant to me.

[LoneWolfGal]

Originally Posted by Luckyman01

I had the same problem, while there can be a number of reasons, in my case I eventually found it to be a bad vacuum hose from the intake to the fuel pressure sensor on the fuel rail.

Viewed from the back on engine compartment, it is on the fuel rail, left upper corner.

Would you happen to have a photo or illustration that shows the location of the vacuum hose?

[Luckyman01]

Just need to shift my lazy self, please give me a day or two

[blue62]

Originally Posted by LoneWolfGal

Would you happen to have a photo or illustration that shows the location of the vacuum hose?

If the hard starting issue only arises after fueling up ......it is most likely an issue with something in the EVAP system. Like a faulty purge valve or cracked vacuum canister or the like.

If you had an issue with a vacuum line to the fuel pressure regulator I would think your hard starting issue would happen more often then just at fuel up.

When you have the hard start issue does holding the gas pedal to the floor help in getting the car to start?

[LoneWolfGal]

Originally Posted by blue62

If the hard starting issue only arises after fueling up ......it is most likely an issue with something in the EVAP system. Like a faulty purge valve or cracked vacuum canister or the like.

If you had an issue with a vacuum line to the fuel pressure regulator I would think your hard starting issue would happen more often then just at fuel up.

When you have the hard start issue does holding the gas pedal to the floor help in getting the car to start?

It's hard starting only after fueling, no other time. Yes, flooring the gas pedal does help to get it running.

[blue62]

Originally Posted by LoneWolfGal

It's hard starting only after fueling, no other time. Yes, flooring the gas pedal does help to get it running.

I would go thru the EVAP system.
If flooring the gas pedal helps get it started then that points towards a too rich mixture when cranking. Flooring the gas pedal opens the throttle body butterfly allowing more air to enter.. so that leans the mixture out and helps get it started.
Now this is all guessing on my part so bear that in mind.
So look for things that could possibly cause a too rick starting mixture.
EVAP issues can do that... things like a stuck open purge valve or vacuum leaks in the hoses that connect up parts of the EVAP system or a cracked charcoal vacuum canister.

You can check the vacuum hose to the fuel pressure regulator as well (simple to do) but I do think if that was the issue it would cause problems a more times then just when you refuel.

[LoneWolfGal]

Originally Posted by blue62

I would go thru the EVAP system.

That makes sense, thanks. After I get the shop manual I ordered, I can get serious about troubleshooting. Right now I'm flying blind without an instrument rating.

[LoneWolfGal]

Originally Posted by blue62

I would go thru the EVAP system.
If flooring the gas pedal helps get it started then that points towards a too rich mixture when cranking. Flooring the gas pedal opens the throttle body butterfly allowing more air to enter.. so that leans the mixture out and helps get it started.
Now this is all guessing on my part so bear that in mind.
So look for things that could possibly cause a too rick starting mixture.
EVAP issues can do that... things like a stuck open purge valve or vacuum leaks in the hoses that connect up parts of the EVAP system or a cracked charcoal vacuum canister.

You can check the vacuum hose to the fuel pressure regulator as well (simple to do) but I do think if that was the issue it would cause problems a more times then just when you refuel.

The more I research the problem, the more convinced I am that you're right about it being an issue with the EVAP system. Good call, blue62. After inspecting the hoses I think I'll begin with replacing the fuel vapor carbon cannister, since it seems the most likely culprit. I'm not getting a CEL and it's my understanding that a cannister issue usually won't throw a code. If replacing it doesn't solve the problem I'll look at the purge valves. In any case, I'm going to wait until my shop manual arrives before tearing into it.

[blue62]

Originally Posted by LoneWolfGal

The more I research the problem, the more convinced I am that you're right about it being an issue with the EVAP system. Good call, blue62. After inspecting the hoses I think I'll begin with replacing the charcoal cannister, since it seems the most likely culprit. I'm not getting a CEL and it's my understanding that a too-full cannister doesn't throw a code. If replacing it doesn't solve the problem I'll look at the purge valves. In any case, I'm going to wait until my shop manual arrives before tearing into it.

You could do a search here on the forum for EVAP system issues.
One of the members here has excellent pictures of various systems on theses cars.
Once you know how things are laid out you can test things like hoses or cannisters by applying a vacuum and see if the vacuum will hold with something like a handy vac.

My reasoning for not going with the fuel pressure regulator vacuum line .... is that at starter cranking speed there is the least amount of vacuum being applied. I could be wrong but it doesn't make sense to me that a vacuum operated fuel pressure regulator would have any affect on fuel pressure with the least amount of vacuum applied.
Much more likely that the fuel pressure regulator comes into play when the greatest amount of vacuum is applied to it.

[LoneWolfGal]

Originally Posted by LoneWolfGal

The more I research the problem, the more convinced I am that you're right about it being an issue with the EVAP system. Good call, blue62. After inspecting the hoses I think I'll begin with replacing the charcoal cannister, since it seems the most likely culprit. I'm not getting a CEL and it's my understanding that a cannister issue usually won't throw a code. If replacing it doesn't solve the problem I'll look at the purge valves. In any case, I'm going to wait until my shop manual arrives before tearing into it.

Continuing to research the matter, I realized it would be a good idea to eliminate the comparatively inexpensive stuff -- hoses, purge valves, etc. -- before I replace the cannister, because a new cannister will set me back $382.50 for a genuine Porsche unit or $329.90 for a knockoff. I'm not used to Porsche's stratospheric prices yet.