No idle/ backfire on overun

[jrt]

Afternoon, I've got another problem I could do with some advise for please.
Our van has this afternoon has started to cut out at junctions/ no idle etc and a slight backfire when on the overun. I've had a look at the advice on here and have started to have a poke about in the engine bay to see if I can sort it out.
Cleaned the plugs, air filter, cone fuel filter in the carb and cleaned up the dizzy. Exhaust is new and fuel filter/lines replaced a few months ago.
The pipe from the choke pull down unit looks a bit soft and in poor condition so going to change this tomorrow along with the short piece to the vacuum unit and see if that improves it.
Is it worth adjusting the choke valve gap or fast idle speed? Never having done owt like this before I'm just a bit nervous of how to go about it, I've had a look in the Haynes and it says to remove the automatic choke body, is that this in the photo
anything to watch out for when removing it?
83 petrol wbx dg 2e3 carb
Cheers David

[Ant-t]

Hi I had the same problem, 83 wbx, it turned out to be the short vacuum pipe which I replaced care of a kind individual on here. No further stalling issues for me so worth a check

[jrt]

Yes, deep down I'm hoping it's that. I changed all but the two pipes mentioned above the other year when it was running a bit rough and it cured it immediately. The pipe from the choke pull down unit came off very easily and looks on the verge of disintegration so i'll pick up a length of vacuum pipe tomorrow, replace them both and see if it cures it.
If this doesn't cure it I was after a list of things I should be checking in order so I can rule stuff out.
David

[300CE]

Hi David, had exactly the same symptoms after a long run in the new forest - back fired twice and inconsistently stalled on my way back home to Kent although always started up without fault.

I replaced the little pieces of rubber at each end of the vacuum pipe just in case they they were letting in air and replaced the vacuum advance unit as it didn't seem to be holding when I sucked on it. It cut out again just the once so I adjusted the mixture on the carb once engine up to temp by turning the screw in until the revs dropped and then back out again to richen the mixture and bring the revs back up, then a quarter turn back in. I have a Weber carb so set up might be different, but itchyfeet put a really useful link up about adjusting the carb (will try to find it).

It's been fine since, no cutting out and ticking over perfectly. That said, I had trouble starting the old girl this morning (usually it's on the button), so I checked spark plugs and looked like they needed changing as the electrodes had worn (haven't changed them since new engine fitted). I've replaced these today so hopefully that'll resolve this, if not I'll be looking at timing & leads.

[kevtherev]

Search my posts for back firing, pull down, pierburg

Have you checked the pull down for leaks?
Just do the simple test before you buy anything.
There's a restrictor in the pull down pipe, this must not be omitted.
Back firing is a classic air leak symptom
Or a blocked idle jet.

[jrt]

Cheers Kev, I've spent the last couple of hours trawling through the various carb'/stalling/idle threads-there's plenty of 'em on here !
Will pick up some vacuum pipe tomorrow because that needs changing, fit that then go on from there.
Just read about the restrictor in the vacuum pipe. mmm didn't notice one when I did the cursory check of the pipe earlier although it may have been in the unit and I didn't see it.
David
E D I T-just been outside for another look, scrabbling about in the dark/fog under the van looking for the end bit I cut off and there isn't anything in the pipe or unit, are they available to buy?

[jrt]

Evening, replaced the remaining vacuum pipes tonight and van idled straight away but still didn't sound right and was struggling to keep going without blipping the accelerator.
Sprayed some carb cleaner around the base of the carb/vacuum pipes and the inlet manifold and hey presto engine responded when it was sprayed around the front of the gasket on the right hand side of the inlet manifold. Looks like the source of the air intake.
David

[jrt]

Just realised I hadn't given a conclusion to this thread. It was the inlet manifold gasket[o/side], replaced both and carb' gasket and now running sweetly.
Thanks for all the help David

[kevtherev]

Thanks for the update

[Ant-t]

Yes glad that you got that sorted, it a pain having no tick over