jotto

The choke on my non original Qjet is not fully opening. It looks like the intermediate lever is hitting the vacuum break so I wondered if I should gently bend that lever or the rod that attaches to the choke plate to allow for full opening. I have voltage going to the choke and it appears to operate correctly off of the car but its the mechanical linkage that is causing it not to fully open ( I think! )

Can anyone post a picture of how the linkage should look on a fully warmed, open choke?

I assume when hot, the choke plate should be held quite firmly in the upright position due to the effect of the bimetal acting on it?

Cheers.

MelWff

did the carburetor choke work correctly in the past?
on a fully cold engine with an air temperature of about 72 degrees the choke should just fully close with no additional tension, is that how it is set?
do you have a copy of the Factory Service manual?

jotto

I think the choke has been failing slowly over a period of time. I have a new choke to fit but when I removed the old one I noticed by manually operating the lever in the choke housing on a hot engine that the choke flap was only opening about 70% and was quite loose. If I move the vacuum break out of the way it opens fully.
I have the factory manual at home but won't be back till the weekend. Just wanted to get a bit of a heads up so I could start wrenching and get her sorted asap.
Appreciate the reply.

jotto

So had a little time to look at the carb today and compare it with the original one I took off.
When manually operating the choke on the original carb, the choke plate is held firmly in the upright position. On the carb that is on the car, doing the same, the choke plate is loose and closes over when the engine runs thus causing the issue I am experiencing.
I could swap the choke rod from my original carb to see if that would make a difference but I want to keep that intact if at all possible.

Looking at the video, should I try bending the rod that operates the plate to try to shorten it a bit.

MelWff

did you look in the FSM section on adjusting the choke, dont want to tell you the wrong thing

jotto

I did have a look, obviously its for the original carb and not this one.

All the adjustments are for setting it up for cold starts, high idle etc and not for when warmed up to normal operating temps.

lars

Jotto -
Have you done the choke setup and adjustment as outlined in my Q-Jet paper? I have a complete setup guide for the choke in that paper. E-mail me if you need a copy.

Lars
V8FastCars@msn.com

Kid Vette

Not sure what model you have but here is mine.

Jeff_Keryk

The choke blade should be vertical.

lars

If the green "tang" on the lever is hitting the plastic bushing on the choke pulloff and preventing the lever from dropping all the way down (and thus limiting the choke opening), this is a very common problem with aftermarket replacement pulloffs. Bend the pulloff by prying against it using a screwdriver between the pulloff and the carb body to move the pulloff slightly away from the carb. This will allow the green tang to clear the pulloff.

Lars

jotto

Thanks for all of the replies.
Lars, I've sent you an email request.

I took the choke linkage apart to check for binding etc and even with the pulloff removed the choke plate is not held vertically and is loose.

lars

I'll get the info out to you as soon as I return to the workshop this evening. Sounds like a basic adjustment setup issue that you will be able to correct using the instructions that I'm sending you.

Lars

jotto

Thanks for the email Lars, I've read it through a few times and will go through the choke setup part step by step over the weekend.
One quick question, if I need to bend the choke rod, can I do it in situ or do I need to remove it so as not to damage anything?
TIA!

sunflower 1972

If yours is a divorced choke like mine, I removed it in order to bend it. With a divorced choke setup, I found that's the easiest way.

JayRay

Are the electric and hot air chokes interchangeable on these Qjets?

lars

The hot air choke carbs can be converted to electric as long as you remove the cover gasket to allow a ground path, and plug the vacuum vent system. If the vacuum vent system is allowed to operate, it will pull cold air into the choke housing and cause the electric choke to operate very slowly.

Lars

lars

As his photos and video show, his carb is an integral-choke M4M - not a 4MV. The choke setup procedures are different.