Twin Choke Weber

[MeMe]

...........when in doubt, the ribnet forum always comes through !

My 1986 Jeep Wrangler, powered by a 4.2L Petrol straight 6 is aided by this TC Weber however and unfortunately, she has become a real pain to start in the morning. Upon investigation I found that the chokes were not closing however, if I pushed them closed manually, she fired up first time as usual.

Further investigation (by the way, my knowledge of engines and mechanics stretches no further than, if I turn the key, or push the button, it starts) I noticed that the auto choke was "loose".

I decided to take if off to see what was inside and found a coil which, I can only describe as something akin to a barometer coil (I hope I'm not getting to technical for you ;-) All looked well so I put it back together and tightened it up !

I figured that when cold the coil would close the chooke and when warm etc etc. That's as far as I've got but it still wont cold start !

So - presuming that this coil cant be broken, what is the methodoligy in setting the same as there are two arrows on the choke and a wire !!!!!


Pictures attached !

[mdt]

IF I am reading your post right there is a wire linked to this choke it is likely that this is sending a signal from a sender unit on the block somewhere? This may be the issue so check the wiring and sender unit.

The other option is to buy a manual conversion kit dead easy to fit even for the non technical? Or you could just pump the throttle 2 or 3 times before you turn the key this will get the pump jets firing enough fuel in to give you a rich mixture to start it?

Good luck

[MeMe]

......sender unit in these pictures ? The wire attached to the choke goes directly back in to the bulk head which I fugured went to a light on the dash to advise the choke was activated however, this light has never lit (should it exist) however, until recently, she always fired up regardless of a light.

[Erin]

Does it need a bit of carb cleaner to free up a sticking choke valve?

[jwalker]

Jeez this is digging into the old brain cells from way back... now, my recollection is that the coil is a bi-metallic strip which warms with the engine and uncoils to rotate the choke butterfly. The setting, to some extent, depends on where you live and how cold it gets and how hot your engine runs. The clamp plate should be slackened and the choke mechanism rotated to make the spring just close the choke butterfly when the engine is cold then retightened. After that, the uncoiling of the spring and the engine suck within the carb will open the butterfly as necessary. It was a fairly crude system but worked ok-ish. As mdt suggests, pumping the throttle, rather slowly cos it takes time for the petrol to squirt in, will get the engine started and may also be necessary on really cold mornings but the engine may not continue to be drivable without the choke working correctly. The fact that it used to be fine and now isn't indicates a failure of some sort so it may need more than simply resetting. I think but can't completely recollect, some used to heat by electric current and others used the engine water to warm the bi-metallic coil.