Electric Choke On Quadrajet Carburetor

[c3po]

I have a 1983 Chevrolet El Camino that when the car is warmed up she runs great.

I have adjusted the choke as well as had it adjusted when the car was cold by my mechanic buddy.

I have sprayed the choke and everything on the carburetor.

I am wondering if the wound up spring inside the choke housing could be bad and need to be replaced, as it seems you are not supposed to spray this item with carb cleaner.

The car starts up fine, but she is running rough until the car warms up, if I hit the gas to move fast when she is cold she backfires. I pretty much just start the car up and let it idle for 2 minutes and then drive around the development slow until the car warms up, any advice would be appreciated.

 

[refuse2]

Is the timing correct for it?

 

[punisher]

If I remember, you adjust the choke hot.

Pull it apart, the 3 screws and the choke coil, see if the bimetallic strip is broken. Usually a bad heat coil or no voltage condition at that heater coil will cause rich running when warm, the opposite of your condition (lean when cold). You can also use a hair dryer to blow hot air across the bimetallic strip and watch it operate.

When the car is cold, pull off the air cleaner housing, cycle the throttle and see if the coil closes the choke. It should be evident if there is any binding by playing with the choke link on the pass side of the carb from the choke coil. It is a simple setup, not too many things can cause your problem.(assuming it is carb related)

 

[c3po]

The timing is correct, I will take the 3 screws off and check it, because when this car is warm or hot she runs fantastic.

 

[ChiTDI]

That element is a wear item on the Q-jet if I remember correctly.

 

[demarpaint]

I always adjusted the choke cold especially if there was an issue with cold starting. Those springs do get messed up and need to be replaced if adjustments don't work. You can also change it over to a manual choke if all else fails. The older automatic chokes can be a real PIA.

 

[punisher]

Something to consider, not all of the chokes are adjustable, especially on later model C3 control setups like this. There is a notch on the housing that mates to the bakelite coil holder and pretty much locks it in place. They don't have the markings on the side. A lot of '81 and up had that setup depending on where it was sold and what emission regs it had to meet.

 

[demarpaint]

Yes his might or might not be adjustable. If his is set up with the notch, then the spring could be bad. I'd consider a hand choke if that's the case.

 

[oilboy123]

Hand chokes are pretty fool proof.

If you are staying with the auto choke make sure the choke pull off diaphram is working properly. If the choke plate does not crack open just as the engine is starting to run it might have a hole in the rubber. If it is bad it could cause a back fire.

The choke coil and the diaphram work together.

 

[c3po]

The original carburetor's choke could not be adjusted, but I have a different carburetor on there now since I do not go through emissions anymore.

I have played with this adjustment and from what I have gathered here and elsewhere on the net that wound up coil inside the choke housing could be bad, since if it is not working properly the car acts like it does not have a choke until fully warmed up.

I will get a handle on this, I am going back to my mechanic buddy tommorow since I have a few others things he needs to take care of. With things being slow up at the chevy dealership, now is the perfect time to go up there.

 

[Rock_Hudstone]

Originally Posted By: c3po

The car starts up fine, but she is running rough until the car warms up, if I hit the gas to move fast when she is cold she backfires. I pretty much just start the car up and let it idle for 2 minutes and then drive around the development slow until the car warms up, any advice would be appreciated.
Try a new primary choke pull off. A common problem on older Q-jets and the symptoms become more pronouced in colder weather.

However, now that you fiddled around with the choke adjustment you may have created another issue even if the choke pulloff was the culprit to begin with.

I wouldn't put too much faith in a dealer mechanic, those guys problably haven't touched a carburator in over 15 years.

 

[c3po]

I understand, but the mechanic I know is 62 years old, but if he cannot do this then I will have to figure this 1 out myself.

I am not too worried since after I get my tailights fixed this car is going in for the rest of the winter and I am only going to be using this car in the warm weather, meaning late spring through early fall.

What other issues could I have created, does a new choke pulloff come with the wound spring. This choke issue started in the early fall and with the weather being colder it is more pronounced.

 

[Rock_Hudstone]

Originally Posted By: c3po
I understand, but the mechanic I know is 62 years old, but if he cannot do this then I will have to figure this 1 out myself.

What other issues could I have created, does a new choke pulloff come with the wound spring. This choke issue started in the early fall and with the weather being colder it is more pronounced.

I would eliminate the choke pull before going any further, the pull-off fails far more often than the choke spring. Buy a new one from Advance, Autozone, or some other place where returns are easy. Throw it on and see if things improve.

Its simple to replace, its the metal diaphram at the front right corner of the carb, two torx screws hold it on.

You may, or may not, have upset the choke adjustment buy moving the plastic cover, hopefully you marked where it was originally.

In general electric chokes don't work as well as the hot air chokes.

 

[tom slick]

Does it fast idle when cold?

 

[RH+G]

Could u take a picture of which carb u have? Also what kind of choke is it? Electric, Divorced Choke, Manual..

 

[c3po]

Originally Posted By: tom slick
Does it fast idle when cold?


It does not fast idle when it is cold. I have a CarQuest right up the street so I will stop in and see what they have, and again it is an ELECTRIC CHOKE.

 

[LeftyLefty]

83 El Camino.
I have one that seemed hard to come off the fast running
after it warmed up. My mechanic finally found the secondary
was hanging up and causing the high speed .
It runs good now with that cleared up.
Mine has a second engine in it and only 120K on
the new Mr Goodwrench.

 

[c3po]

Originally Posted By: LeftyLefty
83 El Camino.
I have one that seemed hard to come off the fast running
after it warmed up. My mechanic finally found the secondary
was hanging up and causing the high speed .
It runs good now with that cleared up.
Mine has a second engine in it and only 120K on
the new Mr Goodwrench.


I once had that problem, but after cleaning all of the linkages it stopped.

I did move the choke the other day but it was revving to high so I put it back to where it was. My problem is that I play with this choke once a year and then forget what I did when it comes time the next year to play with it again.

 

[demarpaint]

Finding a guy that's good with a carb these days is pretty tough. They pretty much when the way of the T-Rex back in the mid 80's IIRC, some cars had FI even sooner.

It will be trial and error. Good luck finding a good re-builder if needed, I think your 62 year old friend is the ticket. No disrespect intended for any of the younger mechanics in the group.

Keep us posted!

 

[c3po]

I think that 1987 was the last year that General Motors had carburetors on there cars, they were pretty much coming out with fuel injection in the early 1980's

If I ever get another engine for this car you can bet that it is going to be fuel injected. The guys that can work on carburetors is a dying breed.