Qjet won't kick down - The 1947 - Present Chevrolet & GMC Truck Message Board Network

57larry · 12-12-2008, 07:23 PM

when it was warm, my 84 C10 with a 350 and Q jet carb ran fine. Now it's cold and it idles high and I can't get it to kick down. it has power going to the electric choke. what should I check? thanks

Restrorob · 12-12-2008, 09:28 PM

Larry,

I would test the choke with a multimeter to make sure it has a closed circuit, It could be blown. Also check your high idle cam and linkage on the carb for any binding/stiffness.

Good Luck

57larry · 12-12-2008, 09:57 PM

ok, thanks, I'll check the ground

Restrorob · 12-12-2008, 11:15 PM

It's not really a 'ground' your checking, Un-plug the wire and set your meter on ohm's scale. Touch one test lead to the wire connector and the other to any part of the carb, You should get a closed circuit reading if not the heater windings are blown.....

57larry · 12-13-2008, 11:43 AM

are the choke windings able to be replaced?

Restrorob · 12-13-2008, 04:41 PM

No, Just replace the choke assembly then adjust while the engine is cold.

84 400 · 12-13-2008, 05:40 PM

I also have a Q- jet question. On my 77 with a 350 if i tap the pedal it kicks down but when I place it back into park after driving it idles high again. Any ideas what could be causing this.

thanks

73chevyman · 12-13-2008, 06:44 PM

its a QJET thats why i got a eldy

84 400 · 12-13-2008, 08:43 PM

Quote:

Originally Posted by 73chevyman

its a QJET thats why i got a eldy

I have an eddy on my 84 and love it. easy to tune and runs dead on all the time. But I am not switching to an eddy on my 77. If anything I will rebuild th e Q jet 25.00 for a rebuild kit and a half hours worth of work..

Anyone have ideas on mine kicking down but idling back up when placed in park?

Thanks

Restrorob · 12-13-2008, 10:20 PM

Quote:

Originally Posted by 84 400

Anyone have ideas on mine kicking down but idling back up when placed in park?

Could be a couple things, When it idles high in park after driving can you tap the gas and have it idle back down ?

**Corts60** · 12-14-2008, 05:26 PM

OK, More than likely your fast idle cam is sticking on the first cam step. One reason could be that your choke pull-off is not operating properly. That cost's about 15 bucks and is a pretty important component that most people overlook during a rebuild. What style choke do you have? Electric, divorced?

Quote:

Originally Posted by 84 400

I have an eddy on my 84 and love it. easy to tune and runs dead on all the time. But I am not switching to an eddy on my 77. If anything I will rebuild th e Q jet 25.00 for a rebuild kit and a half hours worth of work..

Anyone have ideas on mine kicking down but idling back up when placed in park?

Thanks

84 400 · 12-14-2008, 09:24 PM

yes when placed back into park it idles high but will kick down with a tap of the gas. I am not sure what style choke it is . I will have to take a closer look on friday and get back to you.

Albatrossian · 12-15-2008, 07:42 AM

Quote:

Originally Posted by 84 400

yes when placed back into park it idles high but will kick down with a tap of the gas. I am not sure what style choke it is . I will have to take a closer look on friday and get back to you.

More than likely it's the pull off.. I've seen that happen alot.. and a sticking linkage. WD40 it. QJets are awesome carbs.. I have a 780cfm version that I had professionally built. Crisp, clean response that's like a lightswitch. I get good mileage and equal or better performance than any Edelbrock or Holley.

12-12-2008, 07:23 PM	#1
57larry Registered User Join Date: Nov 2007 Location: Indianapolis Posts: 1,161	Qjet won't kick down when it was warm, my 84 C10 with a 350 and Q jet carb ran fine. Now it's cold and it idles high and I can't get it to kick down. it has power going to the electric choke. what should I check? thanks

12-12-2008, 09:28 PM	#2
Restrorob The One And Only !!! Join Date: Jan 2007 Location: Hole in the woods Florida Posts: 4,567	Re: Qjet won't kick down Larry, I would test the choke with a multimeter to make sure it has a closed circuit, It could be blown. Also check your high idle cam and linkage on the carb for any binding/stiffness. Good Luck __________________ 93 Jeep XJ 88 Buick La Sabra Toys; 88 TA-GTA in the works.... 97 GMC Ext. Cab 502 Crate 5 Spd......Sucks Gas But Haulz Azz ! The primary function of an Engineer is to make it difficult for the Fabricator and impossible for the Mechanic. *"Why go out preserved when you can go out beat up, worn out, sliding in sideways screaming, Holy Sh!t What A Ride" !!!*

12-12-2008, 09:57 PM	#3
57larry Registered User Join Date: Nov 2007 Location: Indianapolis Posts: 1,161	Re: Qjet won't kick down ok, thanks, I'll check the ground

12-12-2008, 11:15 PM	#4
Restrorob The One And Only !!! Join Date: Jan 2007 Location: Hole in the woods Florida Posts: 4,567	Re: Qjet won't kick down It's not really a 'ground' your checking, Un-plug the wire and set your meter on ohm's scale. Touch one test lead to the wire connector and the other to any part of the carb, You should get a closed circuit reading if not the heater windings are blown..... __________________ 93 Jeep XJ 88 Buick La Sabra Toys; 88 TA-GTA in the works.... 97 GMC Ext. Cab 502 Crate 5 Spd......Sucks Gas But Haulz Azz ! The primary function of an Engineer is to make it difficult for the Fabricator and impossible for the Mechanic. *"Why go out preserved when you can go out beat up, worn out, sliding in sideways screaming, Holy Sh!t What A Ride" !!!*

12-13-2008, 11:43 AM	#5
57larry Registered User Join Date: Nov 2007 Location: Indianapolis Posts: 1,161	Re: Qjet won't kick down are the choke windings able to be replaced?

12-13-2008, 04:41 PM	#6
Restrorob The One And Only !!! Join Date: Jan 2007 Location: Hole in the woods Florida Posts: 4,567	Re: Qjet won't kick down No, Just replace the choke assembly then adjust while the engine is cold. __________________ 93 Jeep XJ 88 Buick La Sabra Toys; 88 TA-GTA in the works.... 97 GMC Ext. Cab 502 Crate 5 Spd......Sucks Gas But Haulz Azz ! The primary function of an Engineer is to make it difficult for the Fabricator and impossible for the Mechanic. *"Why go out preserved when you can go out beat up, worn out, sliding in sideways screaming, Holy Sh!t What A Ride" !!!*

12-13-2008, 05:40 PM	#7
84 400 Sb 400 club Join Date: Nov 2005 Location: NH / MA Posts: 2,746	Re: Qjet won't kick down I also have a Q- jet question. On my 77 with a 350 if i tap the pedal it kicks down but when I place it back into park after driving it idles high again. Any ideas what could be causing this. thanks __________________ 1984 chevy c10, built 400sb,.(SOLD) 77 K10 Project / daily driver "The Grinch" http://67-72chevytrucks.com/vboard/s...d.php?t=318363 1956 Willys Wagon (327 chevy) Project (Now Buick 225) 1980 Corvette L-48 4 speed 1992 Mustang GT built 5.0 5 speed 1985 C10 LWB Sold 1982 K10 SWB plow truck Parted out 1986 D30 M1028 fire brush truck Parted out

12-13-2008, 06:44 PM	#8
73chevyman Registered User Join Date: Nov 2008 Location: Lusby, MD Posts: 563	Re: Qjet won't kick down its a QJET thats why i got a eldy __________________ http://67-72chevytrucks.com/vboard/group.php?groupid=37 73 C10 Fleetside If it ain't a Chevy it's foreign http://hotridesmag.com/

12-14-2008, 09:24 PM	#12
84 400 Sb 400 club Join Date: Nov 2005 Location: NH / MA Posts: 2,746	Re: Qjet won't kick down yes when placed back into park it idles high but will kick down with a tap of the gas. I am not sure what style choke it is . I will have to take a closer look on friday and get back to you. __________________ 1984 chevy c10, built 400sb,.(SOLD) 77 K10 Project / daily driver "The Grinch" http://67-72chevytrucks.com/vboard/s...d.php?t=318363 1956 Willys Wagon (327 chevy) Project (Now Buick 225) 1980 Corvette L-48 4 speed 1992 Mustang GT built 5.0 5 speed 1985 C10 LWB Sold 1982 K10 SWB plow truck Parted out 1986 D30 M1028 fire brush truck Parted out



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