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Adjusting the choke on 34 PICT 3

Posted: Fri Jun 01, 2001 10:38 am
by 74EMPI
How do you adjust the choke on a Solex 34 PICT 3? I have set it to the standard location using the marks on the choke heating element and the carb and still can't find a happy medium between cold and warm starts. If I adjust the choke by rotating it toward the back of the car(towards me) the car will start okay when warm but will not start when cold. If I go the other way cold starts are okay but the car will not start again when warmed up. I have the carb adjusted so that it runs very well when driving but starting is still a problem. Any suggestions would be much appreciated.

Adjusting the choke on 34 PICT 3

Posted: Fri Jun 01, 2001 4:12 pm
by JordanK
Let the engine get nice and cool, like overnight. then take out the three clamp scres that hold the choke element on. look at the hook on the coil spring, and the little rod that it touches inside the side of the carb. move the rod w/ your finger to make sure that it's free and in good shape. I had one that was actually bent once...anyway, put the choke element back on, w/ the hook facing so it contacts the rod. rotate it towards the front of the car so there is no tension on the spring and it's not touching the rod. now slowly rotate it towards the rear until you feel it contact the rod. move it until the choke plate is all the way, or most of the way closed, just until it stops. you dont' want any tension on the spring, just contact when the plate is closed. sometimes it's easier to hold the choke closed by hand and rotate until you feel the spring hit the rod. at any rate, no tension on the spring. tighten the clamp screws, and try to open the choke by hand w/ the fast idle cam-not too far, just enough to see if you have too much tension on the spring. you're good to go now. it should start right up when cold, and smooth out after a couple of minutes of running. you need to make sure that the set screw that engages the teeth of the fast idle cam isnt' too far in. with the choke in the all the way open position (ie hot, running position) adjust it so the screw on top of the throttle are just barely touches the bottom of the cam, then 1/4" turn more. now don't adjust that one any more, it's right. Try this out and see what you think. it may take a little tweaking but that should get you pretty darn close. keep the choke adjusted, it makes you run rich if you don't. i usually just check it at the oil change time. good luck.

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Jordan
1963 Beetle, 5 spokes, 1776, dropped spindles, etc...
1973 Standard Beetle, stock.

Adjusting the choke on 34 PICT 3

Posted: Fri Jun 01, 2001 4:14 pm
by JordanK
PS if you car starts hard when hot, it could be vapor lock, gas boiling in the line, which forces it past the needle and seat in the carb and floods the engine out. check to see if you have any gas lines laying on the manifold, or if they are near the heat exchangers under the car. however, you are correct, a very rich choke could give the same symptoms. try the choke and see how it goes.

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Jordan
1963 Beetle, 5 spokes, 1776, dropped spindles, etc...
1973 Standard Beetle, stock.

Adjusting the choke on 34 PICT 3

Posted: Fri Jun 01, 2001 5:06 pm
by 74EMPI
Thanks for the input. I'll try it first thing tommorrow. I worked on it this evening and the car started fine but after driving for a half hour or so I shut the car off and let it sit for 10-15 mins. When I tried to start the car it turned over fine but would not start without giving it alot of throttle. Is this related to the choke adjustment?

Adjusting the choke on 34 PICT 3

Posted: Sat Jun 02, 2001 4:15 pm
by JordanK
yes, it sounds like you are very rich when you go to start it. by flooring it you are probably draining the carb bowl, which lets it start. is there a puff of whitish smoke when it finally does fire? that would indicate the vapor lock/too rich problem. will it fire, or even attempt to fire if you dont' touch the gas at all? i had a similiar problem w/ my 73, if i gave it gas it would never fire, but if i stayed off the pedal it would, eventually. that turned out to be a carb adjustment issue, it was way too rich. also, if your timing is off, (either way) it will make the car hard to start when it's hot. Good Luck

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Jordan
1963 Beetle, 5 spokes, 1776, dropped spindles, etc...
1973 Standard Beetle, stock.

Adjusting the choke on 34 PICT 3

Posted: Wed Jun 06, 2001 6:57 am
by 74EMPI
Thanks for the tips on adjusting the choke. That worked perfectly. I believe you are right that the carb is too rich. I adjusted the mixture which seems to have improved the warm start issue. Besides the hard start is there a way to know if you are too rich or too lean? The car has a bit of a flat spot when accelerating and shifting from 1st to 2 nd. Any ideas?

Adjusting the choke on 34 PICT 3

Posted: Wed Jun 06, 2001 3:00 pm
by JordanK
The quick and dirty way is to wipe out your tail pipe really well, then drive the car for 100 miles or so, and see what color it is. if it's jet black you're running too rich. ideally, it should be rich grey, but w/ today's gas that's getting harder and harder. check for the grey right after you've run the car, when it's warm. Not really precise, but it will give you a general idea. the 1st/2nd stumble could indicate richness, but there are LOTS of other causes too, so don't suspect the carb right away. what distributor do you have? Also, you may find that the "all the way closed" choke setting is too much for your area, in that case set it so the set screw rests on the 2nd or 3rd tooth of the fast idle cam. but if it's running ok now, it's up to you. Good Luck

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Jordan
1963 Beetle, 5 spokes, 1776, dropped spindles, etc...
1973 Standard Beetle, stock.