low idle?? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

jmitch333 · 03-18-2010, 06:44 PM

Once again, Ive run into another problem with my 76 c10. I thought replacing the fuel filter would fix this problem but it didnt. The truck doesnt want to idle right. Itll idle low and then stall. This happens in gear and in neutral. It runs fine on the road its just when its at a complete stop and I let off the gas. It idles fine if I barely give it gas. I looked for an idle adjusting screw but couldnt find one. My truck has a 250 straight six one barrel carb 3 speed on the floor setup. Any suggestions?? Thanks in advance.

-Jeff

Hoods69BadBowTie · 03-18-2010, 07:21 PM

Did you try looking for any major vacuum leaks yet? That's weird you should have an idle screw as well maybe not lol.

1LowToy · 03-18-2010, 08:37 PM

There is an electric idle solinoid that holds the idle speed until the motor is shut off. There is also an idle enrichment screw that can be adjusted. They come from the factory sealed off so you cannot touch it. Chances are it has been open up and should be exposed by now. It may be due for a rebuild, I know mine is.

jmitch333 · 03-19-2010, 03:57 PM

Quote:

Originally Posted by 1LowToy

There is an electric idle solinoid that holds the idle speed until the motor is shut off. There is also an idle enrichment screw that can be adjusted. They come from the factory sealed off so you cannot touch it. Chances are it has been open up and should be exposed by now. It may be due for a rebuild, I know mine is.

Where might that screw be hiding?? Several people told me just to rebuild the carb. So Im trying to find a price for a rebuild kit, unless I can find the hidden screw. lol.

jay55jay · 03-19-2010, 05:03 PM

You know what else I had this happen on my GMC pickup. The carburetor gasket was rotted messing up the air to fuel mixture at low idle and Load. I sprayed carb and choke cleaner around the base and it idled up. It may be that worth a shot can't hurt.

jmitch333 · 03-19-2010, 06:15 PM

I found a hex screw at the end of the idle solenoid and found out it was for adjusting "curb idle". I screwed it in some and started the truck and noticed gas leaking from the carb so I unscrewed it and the leak stopped. The truck seemed to be fine with it screwed in so Im wondering if that was it and if so why the heck is the carb leaking gas when that screw is adjusted??

jmitch333 · 03-22-2010, 11:32 AM

Well guys, went ahead and rebuilt the carburetor so hopefully that fixed the issue. Anybody know where I can get the clip that holds the choke lever in place??

jmitch333 · 03-22-2010, 06:04 PM

Well I dont know what to do now.. Replaced the carburetor, truck sounds fine when on the gas but stalls when you let off.. Sometimes when it starts to stall and you pump the gas the carb will pop and the choke snaps to full open.. I think I see a small leak between the bowl and the bottom portion of the carb but its hard to tell. No vacuum leaks as far as I know and the fuel pump is in great shape. I dont know what else to do..

billnorman · 03-23-2010, 06:32 AM

Wish I was there to assist but I'm not. These fuel leaks are important. Get them fixed, before you have a rolling toaster or carry a lot of fire extinguishers and gloves to open a hot hood with. You may have a float issue, either sinking or not adjusted properly which will cause fuel leaks and slow idle. Also, ignition timing too late will slow idle. I never owned a six of that vintage, but if the air flow at idle cannot be adjusted, you must have proper air/fuel mix and timing and no vacuum or fuel leaks to idle at the proper speed. Is your air cleaner dirty?

jmitch333 · 03-23-2010, 09:19 PM

We managed to get it idling but the exhaust spits and sputters and takes easing on the gas to get up to speed but nothing too bad. It gets back and forth.. Would the timing or something of that nature be causing the sputtering?

03-18-2010, 06:44 PM	#1
jmitch333 Registered User Join Date: Mar 2010 Location: Ball, Louisiana Posts: 9	low idle?? Once again, Ive run into another problem with my 76 c10. I thought replacing the fuel filter would fix this problem but it didnt. The truck doesnt want to idle right. Itll idle low and then stall. This happens in gear and in neutral. It runs fine on the road its just when its at a complete stop and I let off the gas. It idles fine if I barely give it gas. I looked for an idle adjusting screw but couldnt find one. My truck has a 250 straight six one barrel carb 3 speed on the floor setup. Any suggestions?? Thanks in advance. -Jeff

03-18-2010, 07:21 PM	#2
Hoods69BadBowTie Chevys Kick A$$ Join Date: Jan 2005 Location: Zootown, MT Posts: 12,699	Re: low idle?? Did you try looking for any major vacuum leaks yet? That's weird you should have an idle screw as well maybe not lol. __________________ HOODS is what I answer too -'79, '77, '88 Pickup Sold, '85 Camaro, '83 T/A, '81,'83,'90 K5 Blazer All Sold -'79 3/4 ton "Big Yellow Bananna" Lifted 4spd. 39.5 TSL Swampers, The money Pit -'86 K5 Blazer Silverado 6.2 4" lift 35"s -'95 Ext. Cab Shorty 4" Tuff Country rolling 35" M/T's -'83 Monte Carlo T-Tops. 126,500 Original Miles -LATER I would rather push a Chevy then drive a ford!!

03-18-2010, 08:37 PM	#3
1LowToy Registered User Join Date: Nov 2009 Location: Sonora California Posts: 860	Re: low idle?? There is an electric idle solinoid that holds the idle speed until the motor is shut off. There is also an idle enrichment screw that can be adjusted. They come from the factory sealed off so you cannot touch it. Chances are it has been open up and should be exposed by now. It may be due for a rebuild, I know mine is. Last edited by 1LowToy; 03-18-2010 at 08:38 PM.

03-19-2010, 05:03 PM	#5
jay55jay Registered User Join Date: Mar 2010 Location: bayville,nj Posts: 165	Re: low idle?? You know what else I had this happen on my GMC pickup. The carburetor gasket was rotted messing up the air to fuel mixture at low idle and Load. I sprayed carb and choke cleaner around the base and it idled up. It may be that worth a shot can't hurt.

03-19-2010, 06:15 PM	#6
jmitch333 Registered User Join Date: Mar 2010 Location: Ball, Louisiana Posts: 9	Re: low idle?? I found a hex screw at the end of the idle solenoid and found out it was for adjusting "curb idle". I screwed it in some and started the truck and noticed gas leaking from the carb so I unscrewed it and the leak stopped. The truck seemed to be fine with it screwed in so Im wondering if that was it and if so why the heck is the carb leaking gas when that screw is adjusted??

03-22-2010, 11:32 AM	#7
jmitch333 Registered User Join Date: Mar 2010 Location: Ball, Louisiana Posts: 9	Re: low idle?? Well guys, went ahead and rebuilt the carburetor so hopefully that fixed the issue. Anybody know where I can get the clip that holds the choke lever in place??

03-22-2010, 06:04 PM	#8
jmitch333 Registered User Join Date: Mar 2010 Location: Ball, Louisiana Posts: 9	Re: low idle?? Well I dont know what to do now.. Replaced the carburetor, truck sounds fine when on the gas but stalls when you let off.. Sometimes when it starts to stall and you pump the gas the carb will pop and the choke snaps to full open.. I think I see a small leak between the bowl and the bottom portion of the carb but its hard to tell. No vacuum leaks as far as I know and the fuel pump is in great shape. I dont know what else to do..

03-23-2010, 06:32 AM	#9
billnorman Registered User Join Date: Mar 2009 Location: glen burnie md Posts: 174	Re: low idle?? Wish I was there to assist but I'm not. These fuel leaks are important. Get them fixed, before you have a rolling toaster or carry a lot of fire extinguishers and gloves to open a hot hood with. You may have a float issue, either sinking or not adjusted properly which will cause fuel leaks and slow idle. Also, ignition timing too late will slow idle. I never owned a six of that vintage, but if the air flow at idle cannot be adjusted, you must have proper air/fuel mix and timing and no vacuum or fuel leaks to idle at the proper speed. Is your air cleaner dirty?

03-23-2010, 09:19 PM	#10
jmitch333 Registered User Join Date: Mar 2010 Location: Ball, Louisiana Posts: 9	Re: low idle?? We managed to get it idling but the exhaust spits and sputters and takes easing on the gas to get up to speed but nothing too bad. It gets back and forth.. Would the timing or something of that nature be causing the sputtering?



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