HELP! 1985 1.9 wbx with 34 dat weber stalling after startup

[Simplymiles]

Hi all i know this has been discussed before but everything ive tried hasnt resolved the issue.

My van will start the first time i try (cold start) but will only run for about 5-10seconds before stalling. It will then not start at all until i leave it for an hour or so and will then proceed to do the exact same thing.
When it does start it seems to idle pretty well and the choke doesn't open too far to go onto the next step on the cam thus reducing the idle speed so am just stumped as to what the problem is. I have checked all components relating to the auto choke and everything seeems to be in order. To me it seems as if it might be overfuelling as smells quite a bit after it has stalled.

Any help would be amazing.

Cheers

[marlinowner]

What fuel pump are you using? Webers don't like pressure above 2 or 3 psi, the float chambers overfill and cause flooding.

[Simplymiles]

Just the standard mechanical pump for the engine. Its a topran brand. It did use to run before with that pump although was always having intermittent starting problems.....

[marlinowner]

I would be tempted to try an electric pump, maybe one like this:
http://www.ebay.co.uk/itm/262643858111" onclick="window.open(this.href);return false;

[Simplymiles]

Might be tempted but don't understand why it now won't run...
Like i said it used to run plus it sounds and runs real smooth for the 10seconds it stays running, just eventually stalls?

[kevtherev]

Was the pushrod changed?

[Simplymiles]

No i have never changed the pushrod. Ive just fully rebuilt the engine from inside out but i had this issue before i took the engine out after the van had been sat on my driveway for 6months without being used....

[kevtherev]

No harm in checking the length.
Should be 100mm

I'm sure you can appreciate remote diagnosis is difficult, we can only surmise from what you tell us.
Are there any other things that seem odd?

When it stalls can you coax it along with throttle?

[Simplymiles]

So it measures 99mm....is that enough wear to give issues?
Also once its starts if i touch the throttle it will stall immediately

[kevtherev]

Stalls if you try to open the throttle when cold
Suggests a weak mixture, partially blocked idle jet, or a significant air leak on the induction side.
Possibly even a timing issue

[Simplymiles]

I have taken the carb apart and checked the jets but didnt have a service kit to fit after so air leak could be potential but was already stalling before i stripped the carb, although i guess the base gasket might be the issue..... Will double check the jets again just to be sure.
Timing.....i mean i havent got a timing light to ensure its spot on but have timed it up according to haynes manual and does seem to run smooth as a whistle when i initially start it up

[kevtherev]

..... does seem to run smooth as a whistle when i initially start it up

I'm confused, so does it stall or not when you start it and use the throttle?

[Simplymiles]

Ha sorry so it will start first try and run nicely for 5-10seconds then will stall on its own accord but if i try and use any throttle to keep it running during this period it will stall immediately.
Then after this it will no longer start at all until i leave the van for about an hour, to which then the same situation will occur again

[kevtherev]

OK
The way I read this is when your choke is fully on the van starts and runs
As soon as you introduce more air (opening the throttle) it stalls
This to me is indicative of a weak mixture.
Or a blocked idle jet
Or a timing fault

Eliminate the simplest first
Timing set at 5 deg btdc (no vacuum)

It is entirely possible that the mixture is too rich!
Only you can decide and act on that.
Maybe check the float height and that the stop "cock" is not damaged letting fuel in.

[Smiffo]

I'm reading it as though it will also stall after 5-10 seconds if just left to idle after startup...!??