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K jet, not holding pressure after siwtchoff

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Hi

My mk1 1.8 1983 GTIhas been suffering from hot start issues. Runs fine, leave it 15 mins or so when hot , wont start churns and churns, if it does start runs rough till it clears its throat. leave it an hour or more to cool and starts fine.Ran the pressure tests (thanks for the Kit mr Quiff)

 All ok as far as I can tell, except pressure immediately plummets to 0 moment the ignition is turned off; as I understand it , it should hold a pressure for up to 20 minutesSo Ive had the fuel pressure regulator out, looks fine, green grommet looks fine , all clean moves freely.Next suspect is the accumulator, but I want to be right as its a £170 part from VW H. My reading suggests there are no specific tests for it, anyone know differentOther suspect is the non return valve . the one next in line to the pump (is that the only one?)

I recall having some issues with the valve which showed the exact same symptoms before when some prat (cant think who that was  ), refitted it the wrong way round. has worked fine since correction ten years ago. I havent touched it sinceWhat can go wrong with return valve and, is that more likely to have failed assuming it can, (or do I face I have stump up and change the accumulator).before I make any  expensive mistakes buying parts I dont need is there anything else I should look at that might cause this?

Cheers in advanceLewis

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with the accumulator look at the end of it there is a small screw, if you can get that out and fuel leaks out of the hole then your accumulator is stuffed.

with the non-return valve its the thing screwed directly in the end of the pump that the fuel line attaches to. these can fail and are relatively cheap:
http://www.classic-vw.co.uk/fuel-pump-check-valve-for-gti-893906093-13453-p.asp

Hello my name is John and I'm a dub addict.



My wiring diagrams and other documents have moved here:

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Aha

Thats really useful thanks,

will the fuel come out of the accumulator under any circumstances ie running recently run etc or doesnt matter?

Ill try that first before looking at the check valve this afternoon

had a nightmare yesterday when one of the pipes to the accumulator (return I think )sprung a leak, fuel hissing everywhere and tank empty in moments

Scary stuff, may well replace all pipes as a precaution even if not cheap

attending my own cremation isnt in my plan……

Would a small leak have a similar effect ( should have mentioned it earlier)?

Lewis

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fuel should never come out of the screw hole on the rear regardless of conditions :)

if that pipe on accumulator has been leaking for a while then it could well be the cause of all your problems, i woudl start by sorting out your lines then see where that gets you :)

Hello my name is John and I'm a dub addict.



My wiring diagrams and other documents have moved here:

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I was thinking that

it may have been leaking a bit before busting completely, ill try the screw trick anyway and see , would be easier to do the lot if it werent £170

The lines i think ill do anyway, the one in the engine bay tot he metering head has a few cracks, its all a bit scary

Had one go under the bonnet in the mk2  a few years, must be me...

Incidentally VWh do accumulators anywhere else do them if they dont have one in?

cheers

L
 

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GSF used to have them in stock, good old ebay worth a look. some ford, audi, porsche, saab, etc use the same one :)

Hello my name is John and I'm a dub addict.



My wiring diagrams and other documents have moved here:

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You'll need to sign into google/gmail for the link to work! (its free!)

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Well

Screw came out quite easily, no leak at all from the accumulator.

So plan to change all the hoses ( not a cheap exercise) as they're all looking a bit aged  and see what happens after that

Will give me some peace of mind, Im still shaken by the force of the leak, you forget how much pressure the system maintains.

Thanks for all advice,

May be back on for advice on pipe changing next…….;)Lewis

 

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When you checked the fuel pressure regulator in the metering head, did you remove the inner plunger and check the small o-ring on the end? If this is letting by you will lose pressure quickly. The small o-ring gets flattened over time.

1986 GTI Cabriolet ("dambuster")

2000 Mk4 Cabriolet Avantgarde (bought for the mrs)

2001 Zafira 1.8

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Erm didnt realise there was one

I took initial guidance from this thread on CGTI http://www.clubgti.com/showthread.php?279048-Long-start-issue-solved!

and the pic of his regulator


Mine looked like this pressure regulator.jpg

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hers the full jobber:

Hello my name is John and I'm a dub addict.



My wiring diagrams and other documents have moved here:

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**SE!

So how do you get that bit out then? I assume its pretty delicate

(thanks for all the advice btw , invaluable)

L

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with careful poking with a suitable pokey implement I guess, mine came out fine so I must have been lucky :lol:

Hello my name is John and I'm a dub addict.



My wiring diagrams and other documents have moved here:

VAG Documents & Downloads

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:lol:Ok fair enough

,Ill have a dig around with a bent paperclip or something,

I thought Id just check there wasnt a more technical approach which Id failed to spotO_o 

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I use a short narrow screwdriver and a bit of patience to ease it out - and don't drop it - they are machined to match the metering head.

1986 GTI Cabriolet ("dambuster")

2000 Mk4 Cabriolet Avantgarde (bought for the mrs)

2001 Zafira 1.8

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Not too bad getting it out, bent plastic coated paperclip, the king of all Pokey thingies

Ok here it is difficult to photo with phone as its so small, couple of shots

the grommet is decidedly square edged and in line with piston rather than round and proud. so should it be replaced

and with what, I assume a rubber grommet is a rubber grommet, just need the right dimensions> kjet piston1.jpg kjet piston2.jpg

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Yes, that looks a bit square!
3.68mm ID x 1.78mm CS for the tip and 6.78mm ID x 1.78mm CS at the other end - I used viton.

1986 GTI Cabriolet ("dambuster")

2000 Mk4 Cabriolet Avantgarde (bought for the mrs)

2001 Zafira 1.8

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Ah ah!!

whod have thunk it.

I found this kickin around the garage ( on the right  from and RC car) , looks about the right size .

may pop that in while i find another to see if it does the job Piston with new grommet.jpg
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