Greetings from Portland

[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.

[blue62]

Originally Posted by LoneWolfGal

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.

If it is a cannister issue (cracked) sometimes they can be repaired.
Keep us posted always like to know outcomes.

[LoneWolfGal]

Originally Posted by blue62

If it is a cannister issue (cracked) sometimes they can be repaired.
Keep us posted always like to know outcomes.

Thanks. I also noticed pre-owned (i.e., used) cannisters are available on eBay for well under $100, supposedly working units. Would you steer clear or give one a shot?

[blue62]

Originally Posted by LoneWolfGal

Thanks. I also noticed pre-owned (i.e., used) cannisters are available on eBay for well under $100, supposedly working units. Would you steer clear or give one a shot?

If you could get conformation that they hold a vacuum it is worth a shot.
Say they are $50.00 $75.00 apiece... that's 4-6 for the price of one new one.
Next thing to consider is how much work is involved in changing a cannister out???
So if they are reasonably priced and changing one out is like an hour or so ya I would go for it.

[LoneWolfGal]

Originally Posted by blue62

If you could get conformation that they hold a vacuum it is worth a shot.
Say they are $50.00 $75.00 apiece... that's 4-6 for the price of one new one.
Next thing to consider is how much work is involved in changing a cannister out???
So if they are reasonably priced and changing one out is like an hour or so ya I would go for it.

I like the way you think, blue62. I'll probably try to eliminate other possible causes first. Anything to postpone wrestling that wheel well liner out.

[Luckyman01]

I think anyone who changes a water pump will have zero issues with a
this job.

Pick up some new fasteners as it is like one or two will fail in the removal process.

David