Starting up after warm with carbs.., i'm confused Options

[Hammy]

My 1.7 has these carbs on it. They have an electric choke so starting it up cold for the first time is quick and good. But i'll go driving around town... Stop at some stores for 10 minutes, and when I come back to start it up, how do I do so? Depress the gas pedal like the first start up? I usually just turn the key and it'll turn over forever but not fire until I pump the gas a lot, then it'll catch and idle extremely low and pop and bitch at you, and you have to rev it for around 20 seconds before it'll idle right... This is embarassing sometimes as I have a lot of pride in my car (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/dry.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/unsure.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/sad.gif) So, How are you supposed to start up after it's warm? Is there a certain way or is something screwed? Also.. there are sometimes some small pops of backfire, not huge blasts but just a small series of pops. I am wondering if this is normal?

Any help would be great. (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

[Joe Bob]

Have you considered disconnecting the chokes?

[Hammy]

I really know little to nothing about mechanics.. So What would disconnecting them give me as a result?

[Joe Ricard]

Well, never fussed with those carbs. But I think the engine cools off enough for it not to run but the choke feels that the engine is warm enough and does not move the choke flaps. Is there a way to adjust the choke temp actuation threshold?
Ya ought to try it with 44IDF's. Actually things are better now that I bumped up to 55 idle jets and the Mallory ignition box. Plenty of gas and enough of a dual sparking fire ball to keep it lit.

[jwalters]

(IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) The methodology I used with my first car, a '73 super beetle, with very similar setup is:

No matter cold, hot, or warm, one full stomp on the pedal is what it took--

But another point--make sure the electric choke covers are adjusted to the proper tension--this should have come with the installation papers--if it is at least 70 degrees outside, they should be fully open and not close at all when you blip the throttle plate open to set them--just loosen up the cover screws and turn in the direction of desired tension very carefully.

Also make sure your idle jets and main jets are sized correctly--have you taken a plug out of both sides to see the burn color??? This simple truth tells all on jetting--you want a light tan color on the insulator---a pure white insulator is too lean, go to bigger jets. A dark to black insulator is too rich, go to smaller jets.

start from new, warm the car then replace the plugs, start and let IDLE for at least 15 min--take a plug out of both sides and refer to color sequence for your idle jet sizes.

A slight color change from light tan means go to only the next available size, up or down, and try it again. A large color differance means go at least two full sizes and try again, keep using the same plugs, just clean them very well.


Make sure your timing is set to spec

Also make sure the mixture screws are adjusted properly---turn in until the engine is about to die, then turn out until it just smoothes out, then keep turning very slowly until the highest idle is reached and then lessens by 50 rpm, do it by ear, the slightest change in engine sound is what you are shooting for, do this three times to each side, one side per time per set. This is a good setting so the engine does not want to overheat at idle for long periods.

Then make sure the sync is still set, if not u should do the whole process over after it is sync'd, I had to do the whole operation, start to finish 4 times before I got both sides of the engine to co-operate and run properly--those carbs have not changed from the same design for over 30 years

[Joe Bob]

Since dual throat carbs usually don't have chokes...electric or otherwise....they are a little harder to start when cold....but they will start with a three or four pumps of the pedal PRIOR to starting....

A LIGHT feathering of the throttle during the use of the starter will generally get a carbed motor going.

Once warm all it needs is a leght feathering again to restart. Chokes are mostly for cold starts...

As mentioned above...you could get the Solex book and look into adjusting them....but it wil be compromise.

Chokes are mandantory to REAL cold weather.

Early 911s with Weber three barrels had a hand throttle for use during starts....they were actually manual chokes and could also be used as a poor man's crusie control.

[Hammy]

I see.... (IMG:http://www.914world.com/bbs2/html/emoticons/blink.gif)

Thank you for the information everyone. So I'm guessing this is basically a trip to my mechanic for an uneducated person like myself? (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

[nebreitling]

QUOTE (Hammy @ Mar 9 2005, 05:39 PM)

I see.... (IMG:http://www.914world.com/bbs2/html/emoticons/blink.gif) Thank you for the information everyone. So I'm guessing this is basically a trip to my mechanic for an uneducated person like myself? (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

nope. dig in and save yourself some money.

[rhodyguy]

take the filters off, get it warm enough for the chokes to open, shut it down for a bit and see if the chokes are reclosing. part of the problem(i think) is the when the engine is hot and then you shut it down for a bit the engine compartment stays pretty warm. the fuel in the carb bowls and lines gets pretty warm. less dense so less charge? my 40 idfs will do the same thing on warm days when it sits for just a few minutes. after 30 mintures or so it will start right up without touching the gas pedle and enough cranking to start drawing fuel. another of the minor carb curses. the cooler fuel will get into the bowls in just a matter of 30 seconds or so. be patient and live with it.

k

[7391420]

I'm all for doing it your self, and like most of us, I do nearly all of the work on my car, but I'll admit that the first time I set my carbs, I had a mechanic I've known for a while do it. He showed me how, charged me accordingly (2 or 3 hrs labor) and now I can do most of it my self.. I'm too young to have ever had a carbed car before this one and I'd never worked with them before so it was totally foreign to me at first. and besides I was scared that I'd F something up and start a fire or something..

-If you've never fiddled with carbs, and you have a mechanic you could ask to show you or let you watch, I dont think it's a bad option..at the very least, you'll be up and running faster!-and unless there is something else going on with the car, you should only be a few hundred poorer...

[Rand]

My $.01 (not quite worth 2 cents)... experiment with different gas pedal positions. Hold the gas pedal half way until it starts. Better or worse? Next time, try full pedal. Don't pump or change the pedal while cranking during this testing phase... just crank until it starts and note the behavior. My bet is you'll find that a certain steady gas pedal position will work quickest.

Mine needs full pedal when cold, half pedal when warm. But it's fuel injected, so it will probably be different. Once you find your nitch though, it should be consistent.