Carb help...

[Muddle238]

Hello people,

I've been having some issues with my car lately, namely regarding the choke. When hot and idling, if I push the choke fully in, the idle speed drops and the engine splutters as if it's about to stall. So I end up having to run with the choke pulled out slightly to get even running.

However, this rather fouls up the plugs with sooty deposits and then I get a misfire, requiring cleaning of the plugs.

Can anyone shed any light on the best course of action? I've tried adjusting the carb, the mixture and idle screws, I've also cleaned and checked the electrode gap on the plugs, however the problem persists.

The car in question is a 1953 Traction Avant. Solex (I think) carb...

Thanks

[droopsnoot]

Is there any chance of anything clogging up the innards of the carb? That is, have you stripped and cleaned the whole carb? I managed to get some "stuff" in my Stromberg carbs just after I'd put the car back on the road, and that caused all sorts of little issues.

Have you also checked for any air leaks in the inlet system? I had a problem on my Firenza (Dellorto carbs) where the HCs were too high to pass an MOT, which turned out to be mainly caused by a hole in the air pipe from the inlet manifold to the servo. I wish I'd noticed before I had all the carbs off the manifold to search for air leaks.

[ASM993]

Just an idea, but have you recently changed your spark plugs? I had some probs with modern plugs but changed to something more suitable and hotter which are much better. There is a chap at the green spark plug company who I spoke to who helped out enormously. My engine had been fouling plugs and displaying signs of running rich, so I rebuilt the carbs (DCOE40s) but the plugs were the real kicker.
As I say, just an idea.
Best of luck with it.

[freddytin]

Unsurprisingly the first jets to get blocked are the smallest,i.e the idle jets.

This is where I would start, a strand or two of copper wire has been useful in the past to wheedle the blockage free.

[DailyHack]

Usually always the jets, well in my experience with my air-cooled Beetle, took apart twice, looked fine...took it apart again found a blocked jet (bizzare how i missed it) "pilot jet" it was in my case I think.

Wouldn't idle, then stall when apply revs

[Muddle238]

Thanks, I will investigate all of the above.

I'd wondered whether the plugs ought to be replaced, repeatedly cleaning can only work for so long.

I blew the jets out but may take a close look, I noticed a few bits of gunk in the filter on the carb. Maybe something has got through to a jet...

[Pantechnicon]

Idle jet blocked