01 Boxster S stalls when warm

[Turd]

After driving 2001 Boxster S (65,000km) for 3 or 4 hours highway or in town, usually both mixed, it begins to stall almost every time I come to an idle. It even stalls at highway speed with clutch engaged when coasting downhill and then jump-starts itself. I have replaced MAF and both front 02 sensors, changed all spark-plugs and air-filter. Got P1119 durametric code before replacing 02 sensor. I also am getting code P1571 (PFC39 immobilizer) but I think it's unrelated. I am not getting engine light or durametric codes (except P1571) since O2 sensor replacement but still stalls as before. Any ideas? Throttle potentiometer? After sitting for a day it runs great again unless I drive for a few hours. HELP! Please!

[harryrcb]

Originally Posted by Turd

After driving 2001 Boxster S (65,000km) for 3 or 4 hours highway or in town, usually both mixed, it begins to stall almost every time I come to an idle. It even stalls at highway speed with clutch engaged when coasting downhill and then jump-starts itself. I have replaced MAF and both front 02 sensors, changed all spark-plugs and air-filter. Got P1119 durametric code before replacing 02 sensor. I also am getting code P1571 (PFC39 immobilizer) but I think it's unrelated. I am not getting engine light or durametric codes (except P1571) since O2 sensor replacement but still stalls as before. Any ideas? Throttle potentiometer? After sitting for a day it runs great again unless I drive for a few hours. HELP! Please!

I had the same thing turned out to be the fuel pump failing, after I repaced that no more stalling. Its dfficult to diagnose because the pump seems to be working when its cold.

[Turd]

Thanks for the tip! Never thought of that. I'll post what happened.

[Turd]

Well upon the suggestion of my Porsche mechanic I replaced the fuel relay instead of the fuel pump, since its a cheaper repair on the path of changing parts to solve an unidentified problem. Took Turd out yesterday for a spin and it stalled routinely again after about 2 hours of driving. Worthy of note that I took it down to about 1/4 tank when it started to stall. Consequently I took harryrcb's advice and ordered a new fuel pump from Pelican Parts last night. It will be interesting to see how well the parcel crosses the border into Canada. Next post will hopefully be that "Turd" is running like a charm!

[Turd]

So upon Harryrc's advice I purchased a fuel pump from Pelican Parts. I ordered the fuel pump from Ladysmith, Canada on a Sunday night and had the fuel pump in my car running 6 days later on Saturday morning! Phenomenal for cross border delivery! That was via US Mail. There was no duty added to the cost. Reading the 101 projects section on replacing the fuel pump in my boxster had me a little apprehensive about "unlocking" the fuel pump from the fuel tank floor. Well to my surprise, my fuel pump was not locked to the floor, but instead was merrily swaying about the bottom of the fuel tank, hanging from the fuel lines and electrical connections. Evidently it had been been doing that for some time as (see photo) the plastic had worn through from rubbing and actually had perforated the pump body. I put the new Pelican parts fuel pump in and locked it to the fuel tank floor, (the whole process from re and re the battery took at most 1.5 hours - and I never completely emptied the fuel tank (took it down to 1/8 tank, but I took a risk I don't recommend!) and my Boxster S, "Turd" runs better than it ever has and does not stall anymore. Thanks Harryrc from Florida for your tip!

[randy_k]

Originally Posted by Turd

So upon Harryrc's advice I purchased a fuel pump from Pelican Parts. I ordered the fuel pump from Ladysmith, Canada on a Sunday night and had the fuel pump in my car running 6 days later on Saturday morning! Phenomenal for cross border delivery! That was via US Mail. There was no duty added to the cost. Reading the 101 projects section on replacing the fuel pump in my boxster had me a little apprehensive about "unlocking" the fuel pump from the fuel tank floor. Well to my surprise, my fuel pump was not locked to the floor, but instead was merrily swaying about the bottom of the fuel tank, hanging from the fuel lines and electrical connections. Evidently it had been been doing that for some time as (see photo) the plastic had worn through from rubbing and actually had perforated the pump body. I put the new Pelican parts fuel pump in and locked it to the fuel tank floor, (the whole process from re and re the battery took at most 1.5 hours - and I never completely emptied the fuel tank (took it down to 1/8 tank, but I took a risk I don't recommend!) and my Boxster S, "Turd" runs better than it ever has and does not stall anymore. Thanks Harryrc from Florida for your tip!

Do you have any tips on doing this job other than running the tank low. Thanks, Randy

[Turd]

Randy, have good lighting. I used a forehead lamp (make sure nobody is watching!) to get the best lighting down into the fuel tank. In hindsight I might have used a siphon to empty the rest of the gas tank out as the fumes were a bit much. I tend to be impatient though and opted against the added time, mess etc with siphoning.

The job was really very easy. The clips on the fuel lines are incredibly easy to remove and reinstall. Take note of which line goes on which fitting. If you look closely the fuel pump lines have a little green mark on them which matches a little green arrow on the pump fitting to indicate which is which. It makes changing boxster spark plugs feel like a walk in the park. Have a really good read of the 101 Projects book (project 22 fuel pump). I read it several times while waiting the 4 days for the pump to arrive. By that time I think I could have done the re. and re. in my sleep. I really like the quantity and clarity of the photos in the 101 Projects book. The book has helped me through not only the fuel pump change but spark plugs change, fuel filter change, drive-shaft change, oxygen sensor change, air-filter change, engine access process, and the proper jacking procedure.

You'll be surprised how easy it is.

[randy_k]

Thanks for the info. I have read and will reread the Pelican book. It does look simple. But one never knows. I'll be doing mine outside in day light. I hope. But nice tip and very funny about the forehead lamp. As it doesn't look like I'll be able to drive it enough to get the fuel out. My plan was, as you mention. To siphon the tank into my wife's Jeep. After all her birthday is around the corner. LOL
Thanks again for the info.
Randy

[Jeff396]

Gasoline......what a thoughtful gift!!! Now I have my wifes gifts all planned out for years! That and with the price of gas she certainly can't complain I'm being cheap!

Seriously, that made me laugh out loud when I read it.

Jeff

[Turd]

Jeff, let's not get carried away! Here in Canada a tank load of Premium fuel for the Boxster can run upwards of $80.00! Unless her birthday happens to fall on Christmas day or Mother's day and you want to double gift you could be way out of line!! You could set a bad precedent for all other Boxster/Cayman owners by raising the bar to such extravagant gifts.....;] I'd recommend more reasonable gifts such an auto air freshener, Windshield washer fluid, tire inflation or perhaps simply spend time with her when she washes/waxes your Boxster. ( I do hope no women read this tech forum.....)

[BYprodriver]

Originally Posted by Turd

Jeff, let's not get carried away! Here in Canada a tank load of Premium fuel for the Boxster can run upwards of $80.00! Unless her birthday happens to fall on Christmas day or Mother's day and you want to double gift you could be way out of line!! You could set a bad precedent for all other Boxster/Cayman owners by raising the bar to such extravagant gifts.....;] I'd recommend more reasonable gifts such an auto air freshener, Windshield washer fluid, tire inflation or perhaps simply spend time with her when she washes/waxes your Boxster. ( I do hope no women read this tech forum.....)

Now we know how you got your name! JK

[Jeff396]

Don't fret, Her birthday is just before Christmas. I figured one tank would be good for both. Only problem is I can't wrap the birthday portion of the gift with X-mas paper.....she especially loves that!!!

Jeff