Electric Choke not Working??? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

*Zilverado* · 11-28-2002, 09:36 AM

So I've gone through the exercise of adjusting my electric choke on my Q-jet but have problems. I go to start the truck when it's cold (I mean cold - I'm in Canada). It starts and runs good and the choke is open about 1/8" as it should be, right? Idle speed is good.

Well, I can stand there and just watch the choke butterfly move. Within minutes - before anything has warmed up - the choke is completely open. Needless to say, the engine isn't ready for no choke, so she reacts accordingly.

So what's going on here?

Is my electric choke not working or what? Is it possible that there is too much voltage in the choke wire, causing it to warm up too fast?

Any suggestions?

*Zilverado* · 11-30-2002, 01:22 AM

Anyone???

Heavy_Steel · 12-05-2002, 11:38 PM

Zilverado, mine does the same thing. Opens right up way too soon, and the engine sputters like crazy. I can push it back shut, and the engine will run smooth again; it's times like this when I wish I had a manual choke!

After messing with it unsuccessfully, I finally dropped it off at my mechanic's today. I'll let you know what he finds.

*Piston* · 12-06-2002, 01:03 AM

The trick is Choke coil tension. If the marks are gone on the front of the coil try adding tension until you find that happy medium. Of course the colder the overall climate is, the more tension you'll need. If your coil is barely closing the choke from lack of tension it will release way too soon. It's also possible to have a shorted coil, one that heats to quickly and draws way to many amps (on the verge of blowing a fuse) but thats not very common. Usually its an adjustment problem.
Also, if the bi-metal spring inside the choke coil has lost its spring action, the choke can be adjusted all day long and never reach the tension needed to keep the choke closed.

Heavy_Steel · 12-07-2002, 08:51 PM

Thanks, Piston. I'll try fiddling with the choke tension screw then if I can find it. Waiting on the Chiltons to arrive (nobody stocks it in town).

My mechanic said the truck worked perfectly for him. Figures.

85 K5 · 12-08-2002, 08:36 AM

Mine is the opposite. Fully warmed up, if shut off for 5 - 10 minutes the choke is closed again.

I've been wondering - the tension adjuster on Q-jets is riveted in place. Is it not adjustable? What if I were to drill out the rivets and replace with screws? Or is that not the adjustment on the Q-jet?

*Piston* · 12-08-2002, 10:33 AM

The factory installes rivets (3), these are drilled out and replaced with either new rivets or screws during the rebuild process. These are self tapping machine screws that will cut through the aluminum housing, dont try to use a regular non tapping screw or you may break the housing.
85 K5, There are 3 possibilities on yours:
Choke heater coil is partially bad and not fully warming
Tubes for the convection heater are not attached (pipes going from carb to intake, from intake to choke).
Or its been adjusted too tightly at some point.

11-28-2002, 09:36 AM	#1
Zilverado Account Suspended Join Date: Nov 2002 Location: Winnipeg, Manitoba, Canada Posts: 798	Electric Choke not Working??? So I've gone through the exercise of adjusting my electric choke on my Q-jet but have problems. I go to start the truck when it's cold (I mean cold - I'm in Canada). It starts and runs good and the choke is open about 1/8" as it should be, right? Idle speed is good. Well, I can stand there and just watch the choke butterfly move. Within minutes - before anything has warmed up - the choke is completely open. Needless to say, the engine isn't ready for no choke, so she reacts accordingly. So what's going on here? Is my electric choke not working or what? Is it possible that there is too much voltage in the choke wire, causing it to warm up too fast? Any suggestions?

11-30-2002, 01:22 AM	#2
Zilverado Account Suspended Join Date: Nov 2002 Location: Winnipeg, Manitoba, Canada Posts: 798	No Suggestions??? Anyone???

12-06-2002, 01:03 AM	#4
Piston Account Suspended Join Date: Oct 2002 Location: Olathe, KS Posts: 2,300	The trick is Choke coil tension. If the marks are gone on the front of the coil try adding tension until you find that happy medium. Of course the colder the overall climate is, the more tension you'll need. If your coil is barely closing the choke from lack of tension it will release way too soon. It's also possible to have a shorted coil, one that heats to quickly and draws way to many amps (on the verge of blowing a fuse) but thats not very common. Usually its an adjustment problem. Also, if the bi-metal spring inside the choke coil has lost its spring action, the choke can be adjusted all day long and never reach the tension needed to keep the choke closed. Last edited by Piston; 12-06-2002 at 01:05 AM.

12-08-2002, 08:36 AM	#6
85 K5 Registered User Join Date: Nov 2002 Location: Spring TX Posts: 113	Mine is the opposite. Fully warmed up, if shut off for 5 - 10 minutes the choke is closed again. I've been wondering - the tension adjuster on Q-jets is riveted in place. Is it not adjustable? What if I were to drill out the rivets and replace with screws? Or is that not the adjustment on the Q-jet? __________________ 350 Crate 10 bolt 3.73 2.5 lift 32x11.50 1904 Edelbrock http://www.oplnk.net/~spirit/K5front.jpg

12-05-2002, 11:38 PM	#3
Heavy_Steel Registered User Join Date: Dec 2002 Location: North Carolina Posts: 8	Zilverado, mine does the same thing. Opens right up way too soon, and the engine sputters like crazy. I can push it back shut, and the engine will run smooth again; it's times like this when I wish I had a manual choke! After messing with it unsuccessfully, I finally dropped it off at my mechanic's today. I'll let you know what he finds.

12-07-2002, 08:51 PM	#5
Heavy_Steel Registered User Join Date: Dec 2002 Location: North Carolina Posts: 8	Thanks, Piston. I'll try fiddling with the choke tension screw then if I can find it. Waiting on the Chiltons to arrive (nobody stocks it in town). My mechanic said the truck worked perfectly for him. Figures.

12-08-2002, 10:33 AM	#7
Piston Account Suspended Join Date: Oct 2002 Location: Olathe, KS Posts: 2,300	The factory installes rivets (3), these are drilled out and replaced with either new rivets or screws during the rebuild process. These are self tapping machine screws that will cut through the aluminum housing, dont try to use a regular non tapping screw or you may break the housing. 85 K5, There are 3 possibilities on yours: Choke heater coil is partially bad and not fully warming Tubes for the convection heater are not attached (pipes going from carb to intake, from intake to choke). Or its been adjusted too tightly at some point.



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