Success! Finally fixed the hard start while hot and fueling issues.
 

I was having a fairly common problem. The car was hard to start once it was hot and l left it resting for about 1/2 hr to an hr. When fueling, the gas would shut off well before the car was full, sometimes turning the fuel nozzle upside down helped, but not always. And then, to start the car after fueling sometimes took over a minute of cranking with the throttle partially open before it caught.

There are all sorts of posts on how to correct the hot hard start problem and its clearly something in the evap system, but there are several very expensive solenoid valves, carbon canisters etc. and I read posts about people spending thousands and not solving the problem.

When I hooked it up to the durametric, I noticed that the fuel trims were at the rich limit and the MAF was reading way below spec, classic case of a vacuum leak. So at the throttle body, I pinched off the hose that comes from the evap system and magically, the fuel trims went back down towards normal, MAF was reading correctly and no more hard start when hot.

So I confirmed it was the evap system but I still hadn't figured out which component it was. Online searches revealed that some said it was the purge valve, a solenoid under the front fender, or the fuel vent valve attached to the gas fill tube or the tank vent valve under the right hand intake manifold. So I dug into the evap sytem under the fender and was able to apply voltage directly to the purge valve and it worked fine, fuel vent valve also seemed to be clear so I took a chance on the vent valve ( $130 at the dealer) under the manifold and viola-all is fixed. No more hot hard start. And when I filled up the tank, it filled completely and then the car started immediately.

I like my car again.

Excellent detective work! This is the valve buried under the left intake manifold? How did you get to it?!

Bravo! Thank you for posting that. I have never had that issue but will definitely print this into my notebook, just incase.

Its not too hard, but a bit time consuming. You have to take off both engine covers and jack the car up. It also makes it a lot easier if you take off the trunk hatch so that you can climb in the trunk which gives much easier access to everything.

Under the left side intake is the valve, it has an electrical connector that has a wire spring that holds it on. just push down on the wire and the connector comes off. Then, with 45 degree needle nose pliers, loosen the clamp that holds the hose going to the throttle body and slide the clamp well clear and take off the hose. You will probably have to use a screw driver to help pry the hose off the valve.

Next is the most difficult part. There is a plastic piece that holds the hard plastic hose on the valve against the underside of the intake manifold. It is absolutely impossible to remove the nut that releases the hose. I ended up jut breaking it off, but beware, the plastic piece is molded into the intake manifold and you might crack the manifold, but I had no problem.

Next, you have to get under the car and release the connector at the end of the hard plastic hose. Its against the firewall way at the bottom. There are two similar hard plastic hoses so be sure you get the right one. Now fish the valve and hose out from the trunk side and put in the new valve/hose. Be sure it threads through correctly along the bulkhead, there's a lot of hoses and wires in there.

I just zip tied the valve to the underside of the manifold.

Great info,I have not had that problem with my 06 Boxster s but my winter beater a toyota Echo did,couldent get fuel in tank,ended up bypassing the charcoal cannister and voila works again,but gasoline fumes will come into the garage now if its left inside.I was told that this problem with fuel not filling and destroying the cannister or parts leading to it is trying to over fuel the tank,fuel will drain back down the overflow into the cannister and destroy it as its only ment for fuel vapours,so when the pump clicks full,pull it out,dont try and squeeze that last few dollars in.

I am having the very same problems, every time I fill up the tank I'm having a hard time to start. But no problem at all with hot engine. The valve you are talking about looks like this?

Excellent Post
 

I just changed the regeneration valve on my wife's 00 Boxster using this post!

It cleared up the hard to start problem after the engine was hot and after gassing her up at the pump.

I would like to inform those that want to not have to crack the clamp / housing that hold the regeneration valve up to the manifold - use an 8mm wrench and take deep breath. I got mine off and back on.

thank you San Rensho for an excellent post.

Fern

Way to go guys, great DIY fixes!
That's what it's all about :)

If pinching the hose solved the problem, why can't you just do that or am I oversimplifying things with a dumb question?

Not at all, good question. It will probably fix the problem, but you will likely still throw codes and possibly not pass inspection if you have emissions testing in you state/country.

Try it and report back if it works or you have any problems.

No emission testing in my neck of the woods. Now I need to figure out which line to pinch.

Theres a rubber hose that goes from the throttle body then under the driver's side intake manifold. Just pinch it off at the throttle body.

Thanks for the info!

Good information anyone care to post some pics to bring additional insight to this issue?

san rensho, what was the part number? From the part number I can probably locate it in one of my photos.

left side air intake distributor
http://986forum.com/forums/uploads01...1400158510.jpg

now a closer look
http://986forum.com/forums/uploads01...1400158644.jpg
http://986forum.com/forums/uploads01...1400158726.jpg
http://986forum.com/forums/uploads01...1400158766.jpg
http://986forum.com/forums/uploads01...1400158798.jpg
this is the left front side of 2004S.

San Rensho is this the part your referring to?

Thanks for the pics- This really helps!!

electrical connection
 

this is what the connection looks like. Squeeze in on curved metal wire which will release securing metal wire on sides, pull/wiggle out connection.

http://986forum.com/forums/uploads01...1400251327.jpg

http://986forum.com/forums/uploads01...1400251364.jpg

That's the one. Its a two part hose, one is hard plastic, the other a rubber hose. Pinch off the rubber hose and if your problems go away, then change out hard plastic hose.

Thanks for the tip.
I had been having the no start after fueling up with my 2000 boxster S plus irregular fast rough idle with cel error codes P0507 P1128 P1130 & P0446.

There is no emission testing in my area so I made a small clamp to clamp off the vacuum line .... worked great !!
No more rough or fast idle & car fuels up with no problems now.
Its been 3 days now with aprox 300 km driven & no cel or error codes yet.

I'm having a bit of a problem discerning what hose to pinch. Is it the part hard plastic/rubber with the horizontal electrical connection? What did use to pinch it with?

No. It's the rubber hose that connects right to the throttle body. If you have identified the hard plastic hose, just trace it back to the throttle body and you will find the soft rubber hose zthat you need to pinch off.

My man San Rensho! The next time I'm in Miami I will buy you the finest scotch we can find! I pinched that bugger off and no starting issues. Better yet no orange eye cyclops staring back at me. Idle and throttle response is great. Thanks again!

QUESTION!!!!!

When my Boxster 986 1997 engine is warm it is slow to crank but fires. I had the battery checked and alternator by Autozone. It just seems like it's a battery problem I don't get it? Any ideas?????????

Any difference in fuel economy? I notice my car running a bit rich and i'm getting about 3-4 mpg lower than usual on an 03S

Can you please provide the part number of the vent valve that needs to be replaced?

Use the photo on Post 6 and go to Pelican. Could be : 99611012906
Don't get confused with the purge valve at the filler neck.
Others will confirm from PET or you can google the PET

I'm resurrecting this thread because I've got the same issue now. Hard to start twice in a row after filling up at the gas station, and throwing P0446. A quick search here gives the solution, thanks everyone for posting the excellent pictures and advice for changing it out!!

It just torques me off to pay $200 for this damn regeneration valve. Probably 250 at the dealer. So I'm going to make an attempt to clean it out and repair it first. If I have any success with that, I'll report back with pictures. Chances are it just needs cleaning - I can't imagine that the solenoid fails.

Maybe there is much cheaper a VW/Audi part that could be substituted ?

Good suggestion. If cleaning doesn't work I could always try a generic $20 solenoid from the auto parts store. Just connect it to the existing hard plastic line. And maybe have to wire in a connector that fits. But it's just a simple normally closed solenoid vacuum valve, very generic in function.

Excellent - we need easily available, generic fixes like this. Sounds like the perfect project for one of our electrical gurus like Particleweave ?

Hey y'all:
I'm just posting here so that future readers who are searching for Porsche Fault Code 68: P0444 will find this thread more easily than I did.

I've been dinkin' around under the hood recently, and this code popped for me. turns-out I (somehow) removed the electrical connector from the EVAP Purge Valve under the left-side intake. I know I was messing around right there (i'll post about that later) but still don;t know how I knocked-off that connecter; it's a wire-retainer, and seems pretty secure. but I've put it back on and the code is not returning.

Thanks Heavens! haha.

A quick question about the hot start problem.

Was the engine cranking ok but not starting?

My car cranks very slowly when warm or hot, only takes a few minutes of running to cause it to not crank well.

Clear as mud.
Can somebody put an arrow on the exact place to pinch off this hose.

How does a person pinch off a hose, anyway?

Vise grip or permanent...fold and zip tie


Sent from my iPhone using Tapatalk

bringing up an old thread though seems a common problem and not cheap fix.

question: does the pinch off the line work? and does it throw a code?

I have ordered a 'bosch' type inline regen valve and will slip in over the weekend... and report back!

my issue is hard starting after fueling up. p0440 cel

i need to crank the engine, while massaging the gas pedal to floor and back a couple times, then sputters to life...

also have a lumpy idle / hunting idle.... quite annoying... check coils and change spark plugs.

while in the engine bay found two hose clamps loose and intake boots undone... so likely my vacuum leak...

question now is; would this cause the p0440 cel? I found these:

P0440:
Faulty EVAP canister purge valve - have no difficulty filling the fuel tank

Blocked fresh air line - not sure what this might be

Leaking EVAP purge valve - most likley

Leaking line between EVAP canister and intake - possible though not clear what's the sympton

EVAP purge valve incorrectly installed - never touched this b4

some mentioned the p0444 cel, here's a good fix... busted wire!

http://986forum.com/forums/performance-technical-chat/82424-p0444-evap-failure.html

Alex Sol,
Any updates ?

I have the exact same two issues:
1. Crank but no start after filling up with any amount of gas. Pump the throttle while cranking and eventually if starts. If you let the car idle in the first few minutes of driving (e.g., stop sign to get out of gas station), the car will stall again.
2. Lumpy idle on occastion.

I bought the part mentioned above (Purge Valve 99611012906). Nearly $300 :eek:, my mechanic suggested I buy the Porsche branded part since he has seen the aftermarket ones fail. Haven't had the chance to install yet since the car is currently stored in another state.

If you don't need the entire line, it is much cheaper to buy just the valve from Pelican:It is OEM.
https://www.pelicanparts.com/More_Info/99611012906.htm?pn=996-110-129-06-M14&bc=c&SVSVSI=0785
Otherwise you are paying $200 for a little hose.