choke problem with Pierburg carb

[kevtherev]

Right lets recap
.
From cold the flap does not open is this the case?

The lever you touched is a cold fast idle mechanism
It is also controlled by the bi metal spring.
It will not affect the flap opening and closing.
When you looked at the spring was it engaged with the lever dog?
And moving the spring moved the flap?

Do you have a Haynes manual?
Can you follow the choke pull down check & setting procedure?
And the push test.

[begemoth]

Thanks Kev

From cold the flap does not open is this the case?

It did not open when I started the engine and left it idling for 6 mins. The mechanic who's looking at it today said that it is normal and it opens only when pressing the pedal while driving (see previous post)

[...]

When you looked at the spring was it engaged with the lever dog?
And moving the spring moved the flap?

It was engaged. I did not move the spring but moved the cog direcly and could see the flap opening and closing accordingly.

Do you have a Haynes manual?
Can you follow the choke pull down check & setting procedure?
And the push test.

Will do as soon as I get the van back.

You don't think it has anything to do with voltage at all?

[kevtherev]

The combination of hot coolant and the choke heater will open the flap.
Regardless of the accelerator position
The fast idle will also step down automatically regardless of the accelerator position
Does the flap open after a more extended period?

We need to find out if the heater element is in working condition.
Can you use a multi meter?
Undo the three retaining screws.
Remove the housing completely
Behind the spring is a heating element
Is it broken?
Test it with a continuity check

The mechanic is describing the choke pull down operation
That's what it does, it pulls the choke open under acceleration in colder weather.
Which stops the engine stalling from over fueling.

[begemoth]

Hi Kev

Back from holiday Got the camper back from the garage - the guy couldn't find anything wrong with it. We took it for the week end and it worked fine. I stopped for a few minutes on the motorway and it restarted without problems but once we got home we unpacked it and I started it again to move it further on the street and it did its old trick again! Started then stalled, then stalled more and more quickly until it just wouldnt start at all.

did not have the tools with me when it happened but I checked today and the flap was fully open. I restarted it and it worked after a few attempts. the flap closed then reopened fine. Can the flap open even after the engine is turned off? If not then the problem might not even be related to the flap at all?!?!?

Can you follow the choke pull down check & setting procedure?
And the push test.

The only thing I found in the manual is how to push the flap to check for resistance. It does resist and when pressed fully the engine slows down and sounds like it is about to stall.

I let the engine run a bit, flap opened fine but I had the impression the engine was running a bit fast, have no way of measuring it though

Thanks

[begemoth]

Happened again yesterday after a long drive back from Dorset but this time I managed to have a look at it and surprise : the flap was fully open!

[begemoth]

Conclusion of this long monologue just in case some else has the same symptoms : was the fuel pump (which was almost new though) which blocked when hot.

[kevtherev]

Thanks for the update
You just can't diagnose that, all you can do is learn from it....and expect the unexpected I suppose