High Idle. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

IOWNATRUCK · 10-23-2011, 11:51 PM

I started my truck today after not starting it for around 1 month, and while in park it was idling very high, but dramatically reduced when put in drive, could not starting it in a while have caused this? I gave it some gas and i believe it slowed down a good bit, so is this something i should be concerned about?

85Bowtie · 10-24-2011, 12:00 AM

Quote:

Originally Posted by IOWNATRUCK

I started my truck today after not starting it for around 1 month, and while in park it was idling very high, but dramatically reduced when put in drive, could not starting it in a while have caused this? I gave it some gas and i believe it slowed down a good bit, so is this something i should be concerned about?

You do know there is a "fast idle" on carbs right? You can set them higher or lower while tuning the carb. When you stab the throttle it usually kicks it off.

379redneck · 10-24-2011, 12:02 AM

Is it tbi or carb? If its tbi and it only does it when you first started it its normal, especialy if its cold out. If you let it run for a little does slow back down?

IOWNATRUCK · 10-24-2011, 12:07 AM

its carb, and it only idles high in park, slows down in every other gear, and after i gave it gas some in park it slowed down a bit.

379redneck · 10-24-2011, 12:15 AM

Did it do it before it sat for a month? Higher idle in park is normal. Is it running rich?

flamingbig10 · 10-24-2011, 12:16 AM

does it Idle high only on cold start ups or all the time

IOWNATRUCK · 10-24-2011, 12:25 AM

No it didnt do it before it sat i dont think, and yeah as the engine warms up or i give it gas, the idle gets a little quieter.

cjlinkster · 10-24-2011, 09:10 PM

Sounds like your fast idle cam is working just fine.

That's normal behavior with a carb. Upon starting up, the fast idle cam bumps up the idle (1800 to 2000 rpm) until the choke has done it's job (then idle drops to spec on the engine sticker).

There might be a chance that your choke pull off is no longer working in spec. It's vacuum operated, so make sure that all of your vacuum lines are in good shape.

IOWNATRUCK · 10-24-2011, 09:33 PM

Okay, will do, thanks to all.

jasonroman · 10-25-2011, 12:44 PM

to not start new thread, ill ask here.

i had the same issue, which i new was normal. but seemed too high for my liking, this past weekend i tuned the truck up. and then messed with carb a bit.....not sure what i did, turned 2 screws a bit....

now, truck starts right up. but quiet as can be, lost the choke action.
just starts and stays around 600
should i turn it again, and try to get the choke action back??

305. think im burning too much gas. or wasting i should say.
3 trips from sayreville to metuchon and empty.

10-23-2011, 11:51 PM	#1
IOWNATRUCK Registered User Join Date: Oct 2011 Location: Matthews, NC Posts: 129	High Idle. I started my truck today after not starting it for around 1 month, and while in park it was idling very high, but dramatically reduced when put in drive, could not starting it in a while have caused this? I gave it some gas and i believe it slowed down a good bit, so is this something i should be concerned about?

10-24-2011, 12:02 AM	#3
379redneck Registered User Join Date: Sep 2010 Location: Kingston, PA Posts: 394	Re: High Idle. Is it tbi or carb? If its tbi and it only does it when you first started it its normal, especialy if its cold out. If you let it run for a little does slow back down? __________________ 87 GMC Sierra 2500 4x4 350/TH350/NP203 Flow Tech long tube headers, throttle body spacer, Edelbrock Performer cam, true dual Flowmaster 40s, 6 inch Superlift suspension lift 2000 silverado extended cab stepside 5.3l. Stock for now

10-24-2011, 12:07 AM	#4
IOWNATRUCK Registered User Join Date: Oct 2011 Location: Matthews, NC Posts: 129	Re: High Idle. its carb, and it only idles high in park, slows down in every other gear, and after i gave it gas some in park it slowed down a bit.

10-24-2011, 12:15 AM	#5
379redneck Registered User Join Date: Sep 2010 Location: Kingston, PA Posts: 394	Re: High Idle. Did it do it before it sat for a month? Higher idle in park is normal. Is it running rich? __________________ 87 GMC Sierra 2500 4x4 350/TH350/NP203 Flow Tech long tube headers, throttle body spacer, Edelbrock Performer cam, true dual Flowmaster 40s, 6 inch Superlift suspension lift 2000 silverado extended cab stepside 5.3l. Stock for now

10-24-2011, 12:16 AM	#6
flamingbig10 6.0 powered square Join Date: Feb 2008 Location: Mesquite texas Posts: 3,459	Re: High Idle. does it Idle high only on cold start ups or all the time __________________ Aaron 1980 c-10 short bed lowered, cammed 6.0, 4l80e 3600 stall, smp tune, wilwoods, and flames best time so far best et 7.86 @87 on motor 7.57 90 on a 75 shot Build http://67-72chevytrucks.com/vboard/s...d.php?t=283326

10-24-2011, 12:25 AM	#7
IOWNATRUCK Registered User Join Date: Oct 2011 Location: Matthews, NC Posts: 129	Re: High Idle. No it didnt do it before it sat i dont think, and yeah as the engine warms up or i give it gas, the idle gets a little quieter.

10-24-2011, 09:10 PM	#8
cjlinkster Registered User Join Date: Jun 2011 Location: Atlanta ga Posts: 150	Re: High Idle. Sounds like your fast idle cam is working just fine. That's normal behavior with a carb. Upon starting up, the fast idle cam bumps up the idle (1800 to 2000 rpm) until the choke has done it's job (then idle drops to spec on the engine sticker). There might be a chance that your choke pull off is no longer working in spec. It's vacuum operated, so make sure that all of your vacuum lines are in good shape. __________________ 1984 C20, 454, 4 speed named "Gold Member"

10-24-2011, 09:33 PM	#9
IOWNATRUCK Registered User Join Date: Oct 2011 Location: Matthews, NC Posts: 129	Re: High Idle. Okay, will do, thanks to all.

10-25-2011, 12:44 PM	#10
jasonroman Registered User Join Date: Jul 2008 Location: sayreville nj Posts: 1,072	Re: High Idle. to not start new thread, ill ask here. i had the same issue, which i new was normal. but seemed too high for my liking, this past weekend i tuned the truck up. and then messed with carb a bit.....not sure what i did, turned 2 screws a bit.... now, truck starts right up. but quiet as can be, lost the choke action. just starts and stays around 600 should i turn it again, and try to get the choke action back?? 305. think im burning too much gas. or wasting i should say. 3 trips from sayreville to metuchon and empty.



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.