Holley Carb Question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

MDC · 02-08-2006, 02:31 AM

I have a 600 Holley w/ manual choke that was running fine until today. I sprayed the engine with degreaser (air cleaner was on) let it sit for about ten minutes then rinsed it off with just a hose. Drove around the block and it acted like the throttle was stuck open. Got home and checked it out. The return spring is still attached and I even tried to push the linkage forward, but it's all the way down. I backed off the idle speed adj screw (all the way)which made very little difference. It has a mech choke that has never been connected since I have owned it. I flipped the linkage to close the choke and after a few seconds it died. Started it back up and tried to adjust the idle mixture which didn't seem to make any difference. I was able to close it all the way and it never shut it off, but I can adjust it out to make it run richer.
Is my carb fried? Or is there something that would make this thing run at a high idle all of a sudden?

CST*TEN in Katy · 02-08-2006, 12:16 PM

I would start by looking to make sure you did not knock loose a vacuum line or vacuum port plug.

MrC1 · 02-08-2006, 12:23 PM

Sounds like you knocked a vacuum line off when you were cleaning. Check really carefully - it may have actually fallen off the back of the engine, so you wouldn't notice it hanging there.

Either that or the grease was sealing upa vacuum leak!

Okay, not funny or very likely.

MDC · 02-08-2006, 12:32 PM

Quote:

Originally Posted by MrC1

Sounds like you knocked a vacuum line off when you were cleaning. Check really carefully - it may have actually fallen off the back of the engine, so you wouldn't notice it hanging there.

Either that or the grease was sealing upa vacuum leak!

Okay, not funny or very likely.

I swear that's what I thought too (the grease seal). If the intake is leaking a little will that cause it? Maybe it's leaking more than I think. It only has vac line from vac advance (converted to HEI) and the brake booster, which are both still connected.

cdowns · 02-08-2006, 05:02 PM

make sure your carb to manifold bolts are still tight/ do you have a th350 tranny?? there's a vaccume line that runs to the modulator also

MDC · 02-08-2006, 06:16 PM

Just a 3 speed manual

MrC1 · 02-08-2006, 06:52 PM

check all the vacuum ports on the carb. If you're not using them all, they should be plugged. Wonder if the plugs could be leaking? Missing?

02-08-2006, 02:31 AM	#1
MDC Registered User Join Date: Oct 2005 Location: N Texas Posts: 727	Holley Carb Question I have a 600 Holley w/ manual choke that was running fine until today. I sprayed the engine with degreaser (air cleaner was on) let it sit for about ten minutes then rinsed it off with just a hose. Drove around the block and it acted like the throttle was stuck open. Got home and checked it out. The return spring is still attached and I even tried to push the linkage forward, but it's all the way down. I backed off the idle speed adj screw (all the way)which made very little difference. It has a mech choke that has never been connected since I have owned it. I flipped the linkage to close the choke and after a few seconds it died. Started it back up and tried to adjust the idle mixture which didn't seem to make any difference. I was able to close it all the way and it never shut it off, but I can adjust it out to make it run richer. Is my carb fried? Or is there something that would make this thing run at a high idle all of a sudden? __________________ 67 C10 Shortbed 327 05 F150 4x4 NO APPOLOGIES 's 02 Xpress X19 02 Yamaha VMax 150 www.xpressboats.com Nothing says 'poor craftmanship' like wrinkles in your duct tape

02-08-2006, 12:16 PM	#2
CST*TEN in Katy Registered User Join Date: Jul 2005 Location: Katy, TX Posts: 48	Re: Holley Carb Question I would start by looking to make sure you did not knock loose a vacuum line or vacuum port plug. __________________ 1970 CST-10 owned it 26 years, finally back on the road after a 10 year rest. 1989 Suburban 1971 Sleekcraft 455Olds Berkeley 1992 SC400 pimp ricer

02-08-2006, 12:23 PM	#3
MrC1 Dork For Days Join Date: Aug 2005 Location: Dallas Posts: 407	Re: Holley Carb Question Sounds like you knocked a vacuum line off when you were cleaning. Check really carefully - it may have actually fallen off the back of the engine, so you wouldn't notice it hanging there. Either that or the grease was sealing upa vacuum leak! Okay, not funny or very likely. __________________ 1972 C20, 402/700R4 - My first classic truck, bought in September 2005. 85% transformed from "Farm" to "Cool" status! 1970 Dodge Challenger 440, 4sp (my other toy) 12.67 @ 117 MPH, with a pathetic 2.022 60' 2007 Dodge Charger SRT-8 2008 Cadillac CTS All-American garage, baby!

02-08-2006, 05:02 PM	#5
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Holley Carb Question make sure your carb to manifold bolts are still tight/ do you have a th350 tranny?? there's a vaccume line that runs to the modulator also __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY Last edited by cdowns; 02-08-2006 at 05:03 PM.

02-08-2006, 06:16 PM	#6
MDC Registered User Join Date: Oct 2005 Location: N Texas Posts: 727	Re: Holley Carb Question Just a 3 speed manual __________________ 67 C10 Shortbed 327 05 F150 4x4 NO APPOLOGIES 's 02 Xpress X19 02 Yamaha VMax 150 www.xpressboats.com Nothing says 'poor craftmanship' like wrinkles in your duct tape

02-08-2006, 06:52 PM	#7
MrC1 Dork For Days Join Date: Aug 2005 Location: Dallas Posts: 407	Re: Holley Carb Question check all the vacuum ports on the carb. If you're not using them all, they should be plugged. Wonder if the plugs could be leaking? Missing? __________________ 1972 C20, 402/700R4 - My first classic truck, bought in September 2005. 85% transformed from "Farm" to "Cool" status! 1970 Dodge Challenger 440, 4sp (my other toy) 12.67 @ 117 MPH, with a pathetic 2.022 60' 2007 Dodge Charger SRT-8 2008 Cadillac CTS All-American garage, baby!



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