Starting issue

[tonydalliday@aol.com]

Hi there. I have a 16v Mk with a starting issue. The engine needs to turn over for 6-8 seconds before firing up. It then runs rough on idle until revved when it is then ok. Run fine other wise. If turned off will start straight away but if left off for 10-15 minutes it struggles to fire up again. A few forums seem to point to the fuel accumilator.  Things like dizzy cap, plugs, rota arm replaced. Any help appreciated

[lemski]

If you look in the mk2 section stickys there is a how to tune your k-jet.
Might help it a little bit.
Have you cracked the fuel banjo to see if the fuel is up there as soon as you crank the engine

[bodga]

If you turn the ign on, wait for the main fuel pump to stop running, turn the ign off then back on to prime again, then try more times to see if it improves starting, if it then starts easier, that would prove your loosing fuel pressure somewere in the system. Accumulator knackered, or main pump on its way out. Is the in tank fuel pump working? That could cause the main pump to struggle to build up pressure to open the injectors, I think they need about 4 or 5 bar to open?

[Gazzmondo]

There is a little screw in the back of the fuel accumulator under the rear of the car. Unscrew it. If any fuel drips out at all, it's shot.
Could be the non-return valve (check valve) on the fuel pump. Also could be Fuel Pressure Regulator Valve in the metering head - the rubber O-rings perish and need replacing. Mine does exactly the same. Takes ages to starts after I've left it for 10-15 minutes after driving it. I've ordered some new O-rings for mine from a local company. VW don't stock them anymore.

Fuel Pressure Regulator:


Non return valve: