the engine doesn't start when it's warm

[japanese girl]

 Hi, everyone. I'm from Japan.
 One of my friends has been a big fan of golf 1
 and I'm translating his problem here into English.
 Hope you'll share your knowledge and experience for us.
 
 His golf1 has the engine problem.
 It starts smoothly when it's cool,
 but he tries to restart it after running for a while, it doesn't.

 He thinks there's something wrong with the control unit or the accumulator
 for he heard some unusual airly noise right after he turned off the engine.
 (pressure problem?)
 
 We'd like to know what the problem might be
 and how we can find out the exact part to be fixed.
 
 Thank you. 

[raferackstraw]

you will need to test the fuel pressures at the metering head with a guage. the accumulator helps to maintain pressure in the system when engine is turned off and restarted when warm. iirc pressure should be around 20psi after 20min. it could also be  leaking injectors

http://www.golfgtiforum.co.uk/index.php?topic=31611.0
http://www.diagnostic-assistance.co.uk/mech_inj.htm
http://www.passat32b.hu/olvasnivalo/kezikonyvek/szervizhez/uzemanyagbefecskendezo%20rendszer%20bosch%20ECI%20Injection_ECI.pdf

have a read of them and also check both fuel pumps are working correctly

[japanese girl]

 Thank you so much for your quick reply
 with the manuals to see.
 
 We'll try and let you know how it goes. 

[japanese girl]

you will need to test the fuel pressures at the metering head with a guage. the accumulator helps to maintain pressure in the system when engine is turned off and restarted when warm. iirc pressure should be around 20psi after 20min.
⇒ there's no pressure at all!

it could also be  leaking injectors ⇒ no problem

have a read of them ⇒ I've been reading them but I know little about cars
                                and my friend, the owner of the car, doesn't understand explanations in English
                                so we're having a difficult time...but we'd love to learn!

and also check both fuel pumps are working correctly ⇒ no problem    

If there are more advice you could give us,
we'll really appreciate that. 


 

[clipperjay]

Is the fuel neck rusty? (The place you put fuel in)
Its not uncommon if it is a metal one and some rusted metal has fallen into the swirl pot in the petrol tank causing blockages in fuel delivery?

It might be worth taking out the petrol tank and check it for dirt metal and blow through the fuel pipes.

Jay
 

[rubjonny]

if you have nbo pressure after you switch the engine off, this points to the fuel accumulator or the non-return valve in the fuel pump. the n-r valve is the part where the fuel line is fitted onto, it unscrews from the end of the pump

[japanese girl]

  Thank you so much for all the advices you gave to us.
 
  The owner and the car shop staff have decided to try a new accumulator.
 
  Finding a new one was another tough work
  (My friend wants to keep his car parts original...)
  and he told me they've finally found one on e-bay America.
 
  This is what has happened so far. 
 
 
 
 
   
 
   

[japanese girl]

if you have nbo pressure after you switch the engine off, this points to the fuel accumulator

 ← at last, he has recieved and tried the new accumulator but the situation hasn't changed, which also means his old accumulator ( he also got this new ) was not broken. So now, he's got two accumulators which seem to be able to work right. He loves parts and he's happy about that...


or the non-return valve in the fuel pump.
←he has checked the valve and it was ok.

so... we haven't found out which parts need to be fixed or changed yet.
Thank you for your advices and does anyone know anything more about the problem?

[raferackstraw]

 i would suggest trying a known working metering head aka fuel distributor. have you tested the fuel pressures with a guage between the warm up regulator and the metering head? you must do this as it will give you an indication of what part is failing.
also in your original post you said he heard an air noise with engine off, which could point to a leak of [possibly fuel] pressure either in the pipes or connectors, is there a smell of fuel?
i would also been checking ignition system is all ok and paticularly the cold start electrics.
is the cold start only working when engine is cold?

[japanese girl]

He sent me a long mail with details and here's the translation
It's so nice of you guys to share all the information and knowledge with me.

i would suggest trying a known working metering head aka fuel distributor. have you tested the fuel pressures with a guage between the warm up regulator and the metering head? you must do this as it will give you an indication of what part is failing.
← Sorry to say this, it's not easy to get a guage here because cars with k-jetronic have never been produced in Japan. VW has changed their Japanese dealers in 1994 plus I can't find any experienced Golf 1 mechanics around the rural area where I live,
which means I need to do everything on my own and am actually thinking about buying one from abroad.
I know I haven't tried a guage but I've assumed that there are no pressure because its injector doesn't do its job when I lift up the sensor plate of the air flow sensor. I've already tried the new warm up regulator, I bought the used one though, nothing has changed.


also in your original post you said he heard an air noise with engine off, which could point to a leak of [possibly fuel] pressure either in the pipes or connectors, is there a smell of fuel?
←The air noise comes from its fuel accumulator, which I think, is releasing too much pressure from the fuel pump. As you can see in the old post, I had a doubt about the accumulator and tried twice. So now I understand that's the normal sound of it, not noise. The fuel lines don't have any problems.

i would also been checking ignition system is all ok and paticularly the cold start electrics.
is the cold start only working when engine is cold?

←And the cold start valve. It only works when the engine is cold.
Maybe if I could arrange the system and make it work with the engine warm, the engine would start...but I don't have such knowledge about the system.

Now, there's only its fuel distributor left to be checked or changed...we can't find a new one in Japan and I know it costs too much for me to get it from abroad. The only thing I can think of is to use the car without stopping its engine.