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Tiny · Joined: 10 Apr 2006 Posts: 502 Location: London, UK

Hi Guys,

Does anyone know where I can get a hold of a new little o-ring for my pressure regulator in my fuel distributor.

My hot start is getting worse, and I am getting a strange "whine" noise (for about 10 seconds) from my fuel distributor, after a bit of fruitless starter cranking.

Same sound from the FD when I jumper the fuel pump relay too.

Im gonna get the gauges out tomorrow.
thanks guys
Tiny

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*****1981 - 924 - Auto - London, UK******

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

SpecialTAuto.com:

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Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

Ozzie · Posted: Fri Mar 07, 2008 7:11 am Post subject:

I bought from Porsche.
$6. IIRC. Shims were the same price.
Probably cheaper elsewhere.
Only one 'o' ring in the euro model and the copper one.
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Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

Mike924 · Joined: 12 Aug 2004 Posts: 2601 Location: IoW UK

If it's a standard metric size, you can get them from a local hardware shop, except they're not normally the fuel-resistant type...

Also, it should be common to some VW CIS models (Golf, Jetta, Scirocco), so they might be able to help.
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1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

'There is no substitute for a little grease under your fingernails.' - Chrenan, 924board.org

Tiny · Joined: 10 Apr 2006 Posts: 502 Location: London, UK

nice 1,

aye ozzie, its only the little one on the end of the piston, for us.
porsche are getting it from germany, as there are none held in the uk stores.
part no. 911 110 936 00
cost £1.24

I checked with VW but they didnt have a breakdown for parts below the metering unit itself which was a hefty £300.00 +
zoiks.

thanks very much guys
Tiny
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*****1981 - 924 - Auto - London, UK******

Tiny · Joined: 10 Apr 2006 Posts: 502 Location: London, UK

I got the new little O-ring... you can see it below next to 2 used ones. It's a slightly chunkier:

but it didn't fix the hot start which has recently got worse = [

Im using the hot start fix, but would rather see my residual pressure maintained as it should be.

New fuel pump and check valve fitted...

So what could it be hmm- fuel accumulator, or

Could it be these new ebay Dr. Injectors? i had to get a 2nd set sent out as the first leaked and had different spring rates. And even with this replacement set, even though they are better....when I lift the air metering plate slightly...they drip before they spray. I re-tested my old bosch ones, and they didn't do that.

False economy part buying?

Tiny
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*****1981 - 924 - Auto - London, UK******

Buwani 931 · Joined: 31 May 2004 Posts: 308 Location: Napa California

Ooops-see below
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1980 931
That's thirty minutes away. I'll be there in ten.

Buwani 931 · Joined: 31 May 2004 Posts: 308 Location: Napa California

Accumulator is easy to test. Remove the little screw in the bottom, see if fuel is coming out after pressure.

Warm up regulator is also possible.Cold start injector also. Does 81 have a freq valve?

Have you tested it with a gauge yet? What were the results?

Where did you get the oring? "Slighly chunkier" does not sound good.

Shawn
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1980 931
That's thirty minutes away. I'll be there in ten.

Tiny · Joined: 10 Apr 2006 Posts: 502 Location: London, UK

Hey Shawn,

Yes I have tested with gauges, and according to procedures in haynes, and k-jet bosch books by probst and watson. My model has no freq valve.

Didn't know the WUR could be possible. How to check?

I will attempt to unscrew that rusty little screw on the bottom of the accumulator tomorrow, after pressure.

Wish we could get this legendary "pb blaster" stuff over here in the uk... I'll give it a go with my propane torch. JOKE !!

Tiny
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*****1981 - 924 - Auto - London, UK******

Buwani 931 · Joined: 31 May 2004 Posts: 308 Location: Napa California

The accumulator is possible but not likely. I would still check it but it would have to dump quite a bit of fuel to be losing residual pressure quickly. The fuel is either
Dumping thru the accumalator ( thats 30? cc of fuel )
Back thru the check valve ( that you replaced )
Into the cylinders or intake (injectors including cold start )
or most likely back into the tank. That would be the regulator o ring that you replaced or WUR.
Perhaps I am missing something but I had this problem and narrowed it down to either the WUR or the regulator oring. I replaced the oring while I was waiting for the WUR so I'm not sure which one fixed it. My WUR needed replacing either way as the spring ( on the turbo models ) was broke.
I think the Probst book shows how to determine between the 2.

Hope this helps

Shawn

Aye on the PB plaster- good stuff
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1980 931
That's thirty minutes away. I'll be there in ten.

Mike924 · Joined: 12 Aug 2004 Posts: 2601 Location: IoW UK

I thought you'd changed the accumulator on your car, Tiny?

Anyway, a new accumulator sorted out the hot-start problem on my car.
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1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

'There is no substitute for a little grease under your fingernails.' - Chrenan, 924board.org

Tiny · Joined: 10 Apr 2006 Posts: 502 Location: London, UK

Hi Mike,

Oh, I asked a question about it in an earlier post as I didn't see the screw on the bottom of mine. Although when I replaced the rear shocks recently, I wire brushed a layer of rust off the accumulator and the screw became visible.

They are quite pricey little blighters, so I thought I'd leave it till later in my hot start hunt. Did you buy yours from Porsche?

RE: The Bosch FI book by Ben Watson explains a procedure to locate the fault causing the fast residual pressure loss, but it requires "pinching off" certain areas such as "the return line from the fuel dist." and I haven't the right tools to safely do this. Not even sure what you would use. I am still trying to fing my book by Probst to see the part that Shawn has mentioned.

Its gotta be around here somewhere!

Tiny

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*****1981 - 924 - Auto - London, UK******

Mike924 · Joined: 12 Aug 2004 Posts: 2601 Location: IoW UK

I got mine from Euro Car Parts. I cheated and bought a Golf GTi unit.

Unfortunately, the inlet connector is a different size (same as the outlet connector), so I had to get a new pump-to-accumulator line made (at a local hydraulics supplier).

You can get a 'pinching' tool from Halfords for about £4. It's actually sold for brake lines. Personally, I'm a bit squeamish about using them, because they have to kink the sides of the hose to work...
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1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

'There is no substitute for a little grease under your fingernails.' - Chrenan, 924board.org