Warm Starting Issues

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hanna.melbo
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Warm Starting Issues

Post by hanna.melbo »

Evening all!
I am having issues re-starting the car once the engine is up to normal operating temperature.
Cold starts are fine with no issues.
Warm starts are an issue.
When turning the key it seems to take an age to turn over once it has finished spluttering around before firing into life albeit rather gingerly.
Once it is running it seems fine.
Any ideas?
Any help is much appreciated!
Thanks in advance


mark1gls
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Re: Warm Starting Issues

Post by mark1gls »

Could be the non return valve on the main fuel pump or the accumulator.

Easy one to test is the accumulator, there is a little screw on the back of it, if you undo the screw and fuel leaks out the accumulator is shot, the seal inside it has perished as fuel is not meant to leak out.

I’ll post a picture of my leaking accumulator from the other week.


Mk1 78 Scirocco GLS 1.6 FR, weekend toy.
Mk1 88 Golf GTi cabriolet 1.8 DX. Daily drive.
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mark1gls
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Re: Warm Starting Issues

Post by mark1gls »

Image


Mine would not stop leaking when I removed the screw so had to seal it up with some silicone till I could replace it.

Image

It lives to the right of the main pump in the picture below.

Image


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Mk1 78 Scirocco GLS 1.6 FR, weekend toy.
Mk1 88 Golf GTi cabriolet 1.8 DX. Daily drive.
Membership No. 323
mark1gls
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Re: Warm Starting Issues

Post by mark1gls »

Forgot to add this just Fuel injection cars…


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Mk1 78 Scirocco GLS 1.6 FR, weekend toy.
Mk1 88 Golf GTi cabriolet 1.8 DX. Daily drive.
Membership No. 323
mark1gls
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Re: Warm Starting Issues

Post by mark1gls »

Non return valve if needed, they also sell replacement hoses from the accumulator to fuel pump if needed?

https://www.classic-vw.co.uk/fuel-pump- ... 3453-p.asp


Mk1 78 Scirocco GLS 1.6 FR, weekend toy.
Mk1 88 Golf GTi cabriolet 1.8 DX. Daily drive.
Membership No. 323
hanna.melbo
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Re: Warm Starting Issues

Post by hanna.melbo »

Brilliant, thank you! I will check tomorrow.
it is an injection model so this is very helpful.
The fuel pump was replaced recently (separate issue) and with it the non return valve.
What is the main purpose of the accumulator?


mark1gls
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Re: Warm Starting Issues

Post by mark1gls »

The accumulator hold the fuel pressure when you switch the engine off and when the engine is warm and you try and start it, the fuel pressure will still be there.

Video explaining it better than I can :-D about 3 mins in but worth watching if you want to know how the fuel injection system works.

https://www.youtube.com/watch?v=a4fJAfXYxWk


Mk1 78 Scirocco GLS 1.6 FR, weekend toy.
Mk1 88 Golf GTi cabriolet 1.8 DX. Daily drive.
Membership No. 323
chopperoli
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Re: Warm Starting Issues

Post by chopperoli »

Do you have a pressure tester? Essential kit Leaky injectors is another possibility, if one injector drips after shutdown, the system loses its rest pressure and floods the engine enough to cause hard restart If it's neither that or what Mark said, then there is also a non return valve in the metering head which can leak down, it is part of the system pressure regulator plunger. You can get kits to replace the old o-rings on that thing and it is quite simple to do.


hanna.melbo
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Re: Warm Starting Issues

Post by hanna.melbo »

thanks Mark / Chopperoli. Fuel came out of the rear screw on the accumulator so i will replace this unit.
Its proving tricky to track down the correct one. It seems there are a load of different part numbers on the market, but confirming compatibility is proving tricky!


mark1gls
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Re: Warm Starting Issues

Post by mark1gls »

Most of them will fit as I brought a good 2nd hand one from a ford capri which is slightly longer and does not have the screw on the back but a tube to feed it back to the fuel tank so I fitted a small bit of hose and put a screw in the end, it works and was a lot cheaper than a new one..

https://www.ebay.co.uk/itm/334676953983 ... BM6LnJkeBh


Mk1 78 Scirocco GLS 1.6 FR, weekend toy.
Mk1 88 Golf GTi cabriolet 1.8 DX. Daily drive.
Membership No. 323
mark1gls
Posts: 3957
Joined: Thu Apr 02, 2009 9:28 pm
fill in the right answer: 10
Location: Somerset

Re: Warm Starting Issues

Post by mark1gls »

I also had to replace a bit of fuel hose as mine would not come undone from the accumulator.

https://www.classic-vw.co.uk/mk1-golf-c ... 4343-p.asp

They also sell other hoses and an accumulator.


Mk1 78 Scirocco GLS 1.6 FR, weekend toy.
Mk1 88 Golf GTi cabriolet 1.8 DX. Daily drive.
Membership No. 323
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