Boxster hard to start after filling with gas

[RFM]

1128 and 1130 = DME on RICH threshold for BOTH cylinder banks = air leak applicable to both banks (something central: bellows, oil filler tube/cap, AOS, tank vent., rubber sleeves intake manifold, vacuum lines/connectors, brake booster, etc.) or MAF sensor, are most common.

1117 = O2 sensor heating, post cat. bank 1

0446 = EVAP canister shut off valve function below lower limit.

I would check that system closer 0446 and 1128/1130 could be related, clear 1117 and look if it come back.

[txhokie4life]

Replace the carbon canister and purge valve this morning.

took a leisurely 2.5 hours. Since this was my first time, I think I could have cut 30-60 minutes off the time

if I had to do it again.

Took a little while to find the purge valve. It is tucked up under the wheel well -- a little towards the top ~12:30-1 o-clock position.

I took a couple pix to help the next person....

BTW, getting the purge valve out and pack in was a little tough -- its in there pretty good.

Once I got it out, took a little bit to get the new one back in -- a little oil on the o-rings

made a huge difference.

Mike

Well it is back -- same P0446.

I'm also getting P1128, P1130, and P1117 -- not sure if they are related. (I was getting them before)

I replaced the canister and purge valve.

This is my sister-in-laws car -- hard to start today after many errands -- finally had to rescue her with a jump.

got back pulled the codes -- it started right up several times -- one time it did hunt idle -- and dropped to about 400rpm.

let it hunt for a bit and then gave it some gas -- then it seemed fine.

i ran duramatic -- could not hear purge valve come on -- went home and checked on my boxster -- sound is

very feighnt -- so it might have -- I'll have to try again now that I know what I am listening for.

took the old valve and tested it with 12v -- seemed to work fine.

worst thing in the world is sister-in-law with no hubby with an unreliable car.

next steps?

check purge valve operation

check purge valve voltage

I didn't have compressed air when I did the evap/purge valve replacement -- will blow out lines.

???

maybe p1128, p1130, and P1117 unrelated -- not sure.

any suggestions welcome.

thx,

mike

Just to add a little more to the story.

Drove the car to my shop tonite. Loud whistle/whir coming from passenger side -- closer inspection

the new purge valve seems to be working.

Sound was coming from the gas fill area -- right where the purge line was -- not sure if the air was coming

or going -- but it was certainly moving.

There seemed to be some serious air movement -- just wasn't sure which way.

I'm sure when I have a few moments I'll be able to figure that out.

But it sure made a lot of noise -- so I suspect the lines are fouled. I just didn't have an air compressor

at the house when I was working on it last weekend. note this sound was described to me

by my sister-in law -- and definitely wasn't there before I replaced the canister and purge valve.

It was loud enough that while you wouldn't mistake it for a radiator fan -- it was getting there!

First time I opened up the gas latch -- it stopped -- seemed to be a good seal on the gas cap as well.

I could get it to start again by giving it some gas --

the third time I induced it -- it did it for probably 5 minutes straight as we discussed amongst ourselves

the history of the problem.

So here is hoping that blowing out the lines and checking them good will resolve at least part of the issue.

Unfortunately -- I'll be traveling -- so I'm handed it off to my cohort -- hopefully it will all be resolved

by the time I get back.

for all those with the same problem -- I'll keep you posted.

Mike

[txhokie4life]

Was able to test all valves and blow out all the hoses except the one from the tank.

It seems to be the one that is the source of the noise.

It goes from tank to charcoal canister?

Anyone know whether cleaning it out with some sort of vacuum might work?

or is the clogging caused by something that will require the line to be physically

replaced? Replacement of course looks to be quite a bear to do.

thx,

Mike

[txhokie4life]

Was able to test all valves and blow out all the hoses except the one from the tank.

It seems to be the one that is the source of the noise.

It goes from tank to charcoal canister?

Anyone know whether cleaning it out with some sort of vacuum might work?

or is the clogging caused by something that will require the line to be physically

replaced? Replacement of course looks to be quite a bear to do.

thx,

Mike

Will double check -- but was told the tube from the tank also was

hit with compressed air --

What actually blocks these lines? Do we need to snake them to physically remove obstruction?

the whistle is coming from fuel door at the purge opening. Fairly good amount of air pressure there.

you can put your thumb on it -- but when not plugged with thumb there is a good amount of air flowing

and an pretty audible lower octave whistle.

thoughts?

Mike

[txhokie4life]

SOLVED!

This was a bear of a problem.

The whistle was caused by too much vacuum in the lines -- if you tapped the valve housing (#8 in previous pdf picture)

just right -- you could get it to resonate and whistle.

There were times it did not resonate at all -- at these times the vacuum was not as strong.

The key was determining this relationship.

There is a valve that controls the Evaporative shut-off valve. It was malfunctioning.

This valve is located under the intake plenum back in the engine. However the noise

emminates from the fuel door! Disconnecting the connector mimics the failure mode,

so in a sense the valve failed stuck open.

We pulled the hose that comes from this valve to the intake manifold right at the Y of the

hose that comes from the AOS. If we taped that hose off -- the engine ran fine.

If we left it open -- it mimiced the hard start after fueling to a T -- including having

to give it gas to keep it from stalling.

Once we replaced the evaporator shut off valve the vacuum reduced and was consistent.

The engine ran really well, and we have since filled it with gas with no issues.

Sadly I replaced the purge valve, and the charcoal canister up front to the tune

of $200 -- and a ton of wasted time. But now we know.

Hope this helps some other folks.

cheers,

Mike

Was able to test all valves and blow out all the hoses except the one from the tank.

It seems to be the one that is the source of the noise.

It goes from tank to charcoal canister?

Anyone know whether cleaning it out with some sort of vacuum might work?

or is the clogging caused by something that will require the line to be physically

replaced? Replacement of course looks to be quite a bear to do.

thx,

Mike

Will double check -- but was told the tube from the tank also was

hit with compressed air --

What actually blocks these lines? Do we need to snake them to physically remove obstruction?

the whistle is coming from fuel door at the purge opening. Fairly good amount of air pressure there.

you can put your thumb on it -- but when not plugged with thumb there is a good amount of air flowing

and an pretty audible lower octave whistle.

thoughts?

Mike

[txhokie4life]

Well I though it was solved --

We did fill it with gas and had no problems, car ran good all day too.

But after driving around today -- the CEL came on again.

This time we have 5 codes

P0447

P0446

P0450

P0444

and

P1117

running out of ideas,

we've replaced the canister

shutoff valve, and purge valve.

Only thing I can think of is to get the meter out and start probing voltages.

any suggestions?????

thx,

Mike

[tenchy72]

Anyone have additional information on this. I have a similar issue but I get code P1128 and P1130 with that same howling noise.

 

Kind Regards,

[txhokie4life]

I hate when folks put out questions -- resolve it -- and don't finish up by giving back to the community.  Guilty on this account.

 

I think I was able to resolve this by replacing the purge control valve under the drivers side intake.  (it's been 5 years -- so forgive me if I don't remember 100% correct).

 

There is a CEL code that popped up - the first time it had the noise -- a second car just the code.  I do not know if the noise was solely due

to replacing this purge valve or I solved that in intermediate steps and the CEL was solved by the purge valve.   I went the painful and expensive route

of doing everything around the gas tank first.  I don't remember the order of when the noise stopped.

 

There are 2 ways to do this purge valve  -- the cheater way and the right way :-)  -- I've done both.

 

The cheater way is to get the pipe from bottom of engine bay towards fuel tank, the purge valve and connection all the way to AOS tube (I think if memory serves me right)

and just bypass the existing valve.

 

The proper way of course is to actually reach underneath the intake and replace the valve.  it's a blind, I think there is one M10 bolt that holds it down and a couple

push to release hose connections.  kind of a pain but very doable.

 

Mike

[tenchy72]

Thanks for the update. I am going to look at it this week end.

 

Kind Regards,

[ZoSo]

2001 Boxster S

I had the same "hard to start after refueling.

I checked all the same things I'm seeing here.

The fix was the Regeneration Valve from throttle body for Fuel Vapor System

Pt# 996-110-129-06--M100

You should be able to take a stethoscope hold it against the regeneration valve body where the electrical connection is and with the engine running there should be a noticeable clicking inside the valve. If none it's not working try tapping on the body it may start working.. I lubed the heck out of mine... Sprayed electrical cleaner with lubricant (plastic safe) and let it soak overnight put it back and I got another 7500 miles out of it.! Just recently replaced.. Now I'm with another problem.. I'll figure it out fix it and grr it's just worth it.