1.9DG not starting after weeks parked

[flora]

I have a starting problem with my 1987 1.9dg petrol waterboxer after being parked for several weeks on the drive. Despite prolonged churning of the engine, the petrol pump fails to get fuel into the carb. If I take the fuel feed off the carb and suck until the fuel reaches me, then reconnect, she will start after the carb fills. She will then run without problems until she is again left for a few weeks. There is mechanical clicking from the pump as I suck the fuel up.

There is no problem starting her if she is left for a few hours, or if she is left for just two or three days.

The fuel piping is new, the petrol pump (German) is a couple of years old and fitted with the cam push rod that came with the pump. As far as I can tell, the petrol tank and breather pipes are ok. My drive, where she is parked does slope, but not steeply, and she is normally parked facing down the slope.

I wonder if anyone has had a similar experience, and can suggest possible lines of investigation? I have looked at the Forums, but can't see any similar threads.

Cheers, Flora

[937carrera]

It's probably just the fuel evaporating from the float chamber and the pump is struggling to pull it through.

Pour an eggcup full of fuel down the throat of the carb and she'll probably start and run fine.

[itchyfeet]

It's probably just the fuel evaporating from the float chamber and the pump is struggling to pull it through.

Pour an eggcup full of fuel down the throat of the carb and she'll probably start and run fine.

+1, common problem especially in summer.

[MarkBos]

Hi
I used to suffer with thi
When i changed my fuel lines a year or two ago i added a one way valve, just before the fuel line travels up to the rear bulkhead. This solved the problem for me
Mark

[flora]

Thanks. I have added a non-return valve to the input fuel line, and will see how the starting goes after a few weeks of sitting on the drive.
Flora.

[bigherb]

Recheck the pump push rod length the replacements are "pooh".

[aknapper]

I used to have this problem as well. Eventually diagnosed as a mechanical fuel pump failure.
I replaced it with a JK version and I've had no problems since. Should be somewhere on the forums what the correct length of the cam pin is - might be worthwhile checking and/or buy a new one from Brickwerks. And it's not unheard of for the pump diaphragm to fail even on 'new' pumps.
A non-return valve is a good idea but I wonder if that just masks finding out what the real problem is?
There is a small fuel filter in the pipe where the fuel inlet line goes to the carb - might be worthwhile taking it out and making sure it isn't full of crud as that could be starving it of petrol.
If you continue to have problems you may need to strip down the Pierburg carb and make sure everything is working correctly and lines are clear. VW Heritage sells a good seal kit and there are some great 'how-to for dummies' videos on youtube by James Aker (Sir Adventure) on refurbing the carb.

[DoubleOSeven]

The fuel pump on these vans came straight off the type 1 and those were gravity fed, these are not. So for fear of ending your starter motors life early I’d go with the Pierburg one way valve.

[flora]

Well, after fitting a Pierburg one-way valve (Brickwerks) in the input fuel line, and then leaving her parked pointing down the drive for two and a half weeks, I tried starting her this morning. After some expected brief churning to refill the carb, she started and ran normally. Thanks for all your comments, the support is much appreciated.

[DoubleOSeven]

Another Club 80-90 success