85 Chevy C10 idling way too high ... help! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

roblando · 04-09-2002, 07:24 AM

Hello all, I'm very green with mechanics and new to the forum. I have an 85 Chevy C10 6cyl 4.3 auto 2wd. I used foam gunk to clean engine. Stupid me did not cover anything. After I was done, I turn engine, but at very high idle. I turn off, took off cover and air filter, sprayed gumout carb cleaner and wd40 to outer linkages ... still too high, dangerous to drive (hard to brake). I ran out of options ... someone help with ideas please!!!

**MJN** · 04-09-2002, 09:59 AM

If the engine is carbureted then the throttle may be sticky or the idle screw is in too far. Also check to see if the choke is holding at high idle. IF it is electric it may have been damaged from the cleaner. Hope this helps a little.

roblando · 04-09-2002, 12:11 PM

Thanks, you were right about it sticking. It was the (cold engine) high idle. When I cleaned engine yesterday, I must have removed the little lube it had or some debris made it stick. I do have a vacuum loose ... no idea where it goes ... (the other two next to it are connected). How do I adjust the idle screw? It's not slotted. At least the idle went down ... whew, what a relief! thanks again

**MJN** · 04-09-2002, 07:58 PM

The idle screw is by the throttle linkage and should just be a regular old machine screw. Just turn it in to open the throttle or out to close it. The choke idle may need adjustment afterwards but maybe not. Glad I was of some help to you.

roblando · 04-10-2002, 06:42 AM

Thanks guys ... yes, you were a big help. I found out where the "runaway" vacuum goes ... right under the air filter cover ... duh! Just goes to show how green I am. I'll adjust the the idle today. She's running at a tad low idle, but, I'll take that rather the high idle it was at!!! thanks again for all your help.
robster.

04-09-2002, 07:24 AM	#1
roblando Registered User Join Date: Apr 2002 Location: Apopka, FL, USA Posts: 4	85 Chevy C10 idling way too high ... help! Hello all, I'm very green with mechanics and new to the forum. I have an 85 Chevy C10 6cyl 4.3 auto 2wd. I used foam gunk to clean engine. Stupid me did not cover anything. After I was done, I turn engine, but at very high idle. I turn off, took off cover and air filter, sprayed gumout carb cleaner and wd40 to outer linkages ... still too high, dangerous to drive (hard to brake). I ran out of options ... someone help with ideas please!!!

04-09-2002, 09:59 AM	#2
MJN Registered User Join Date: Feb 2000 Location: Maquoketa, Ia/ Orr, Mn Posts: 2,983	If the engine is carbureted then the throttle may be sticky or the idle screw is in too far. Also check to see if the choke is holding at high idle. IF it is electric it may have been damaged from the cleaner. Hope this helps a little. __________________ '51 South Bend Model "9A" '56 Chevy 3600 NAPCO '74 Chevy Cheyenne Super K20-restored on 37's '72 GMC Sierra Custom K2500- in progress '08 GMC Envoy Denali '12 GMC Sierra 2500HD Denali '17 GMC Yukon XL VCCA member #58596 http://www.nohrco.com

04-09-2002, 07:58 PM	#4
MJN Registered User Join Date: Feb 2000 Location: Maquoketa, Ia/ Orr, Mn Posts: 2,983	The idle screw is by the throttle linkage and should just be a regular old machine screw. Just turn it in to open the throttle or out to close it. The choke idle may need adjustment afterwards but maybe not. Glad I was of some help to you. __________________ '51 South Bend Model "9A" '56 Chevy 3600 NAPCO '74 Chevy Cheyenne Super K20-restored on 37's '72 GMC Sierra Custom K2500- in progress '08 GMC Envoy Denali '12 GMC Sierra 2500HD Denali '17 GMC Yukon XL VCCA member #58596 http://www.nohrco.com

04-09-2002, 12:11 PM	#3
roblando Registered User Join Date: Apr 2002 Location: Apopka, FL, USA Posts: 4	Thanks, you were right about it sticking. It was the (cold engine) high idle. When I cleaned engine yesterday, I must have removed the little lube it had or some debris made it stick. I do have a vacuum loose ... no idea where it goes ... (the other two next to it are connected). How do I adjust the idle screw? It's not slotted. At least the idle went down ... whew, what a relief! thanks again

04-10-2002, 06:42 AM	#5
roblando Registered User Join Date: Apr 2002 Location: Apopka, FL, USA Posts: 4	Thanks guys ... yes, you were a big help. I found out where the "runaway" vacuum goes ... right under the air filter cover ... duh! Just goes to show how green I am. I'll adjust the the idle today. She's running at a tad low idle, but, I'll take that rather the high idle it was at!!! thanks again for all your help. robster.



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