peter.s

Active Member
Jul 7, 2014
45
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HI - I'm having starting trouble with my Mk1 TDi.

In the mornings, or after it has been left for a day or two it is reluctant to start. The motor turns over but it's not firing - like it's not getting any fuel. After a couple of attempts it will start, cough a little then seem alright. After that it starts fine until another day when it has trouble again.

The battery is just 6 months old, so I doubt that is the problem. It started to happen the day after after I filled up with fuel, could it be dirty fuel?

Any other ideas?
 
HI - I'm having starting trouble with my Mk1 TDi.

In the mornings, or after it has been left for a day or two it is reluctant to start. The motor turns over but it's not firing - like it's not getting any fuel. After a couple of attempts it will start, cough a little then seem alright. After that it starts fine until another day when it has trouble again.

The battery is just 6 months old, so I doubt that is the problem. It started to happen the day after after I filled up with fuel, could it be dirty fuel?

Any other ideas?

Is there any smoke from the exhaust?
Are you losing coolant?
How long since it's had a good service, changing the Air and Fuel filters?
 
Thanks for your interest - I changed the air, oil and fuel filters almost exactly 10,000km ago. It doesn't appear to be losing coolant and I haven't noticed any smoke. Last time I started it I checked for smoke in the mirror and saw none.
Actually last time I started it, it started fine then coughed and died, so I tried restarting it as described in my first message. After a couple of tries it started and idled happily. Hmmm!
 
No smoke and no coolant are good as that good be a head gasket issue and losing compression, likewise unlikely to be an injector issue.

I think you are right to follow the fuel route, a small leak could lower pressure and upset starting. For the small cost I'd pop in a new fuel filter, the o seals on the valve at top could have weakened.
 
uk-audis.net/topic/3118-tandem-pump/

I can't post full link yet but that's the pump diagram and how it's internals work, it supply's fuel to the injectors and also creates the vacuum for the car.
 
The pipe that's circled on the first post is going to the tandem pump that's also just on view in the picture.

uk-mkivs.net/topic/97817-fuel-pressure-pre-tandem-pump/
 
Thanks for this. I don't think mine is a PD though, but I'll have another look under the bonet later today. Cheers
 
I found the problem. The plastic engine cover has worn a small hole in the clear plastic fuel line - which runs from the fuel filter!

The hole is too small to leak fuel, but big enough to draw air. I temporarily fixed it with some tape, but now I need to figure out where to find a replacement clear fuel hose.
 
I found the problem. The plastic engine cover has worn a small hole in the clear plastic fuel line - which runs from the fuel filter!

The hole is too small to leak fuel, but big enough to draw air. I temporarily fixed it with some tape, but now I need to figure out where to find a replacement clear fuel hose.

Nice find mate, I took my engine cover off due to it rubbing on my Air Con pipe, it's smoothed quite a bit off it too...

I've no intention of putting it back on though, it can stay off now plus gives me more access to the engine without having to unbolt it! :)

--Lee