VERY high idle - ZR-1 Net Registry Forums

orthodoct · 10-21-2016

Gentlemen:
New injectors, clutch, chip from Marc, plenum rebuild, headers, Corsa exhaust 18 months ago. Driving on country road today, passed a "turtle". Idle wouldn't drop below 4000. Had a heck of a time getting to destination! Checked everything roadside that I could, no change idle. Parked car for 1 1/2 hours, restarted, idle 2000 (normally 1100). Drove home, slow to return to idle with clutch in. Had similar problem when rebuilt and was IAC problem. Have a spare from Jerry. Before I tackle it, any other ideas of where to look? Cables are not stuck.
Thanks, my friends!
Ty
Crossville, TN

secondchance · 10-21-2016

I would look for vacuum leak.

orthodoct · 10-21-2016

Thanks, nothing obvious, but will check further.

XfireZ51 · 10-21-2016

Is the car stock? NORMAL idle is 1100????

orthodoct · 10-21-2016

Marc Haibeck chip, new injectors from Jerry, Stainless Works ceramic coated headers with cats, Corsa stainless exhaust; everything else stock. 1992; have owned since new, stock idle has always been 1000 or so.
Thanks!

XfireZ51 · 10-21-2016

Quote:

Originally Posted by orthodoct

Marc Haibeck chip, new injectors from Jerry, Stainless Works ceramic coated headers with cats, Corsa stainless exhaust; everything else stock. 1992; have owned since new, stock idle has always been 1000 or so.
Thanks!

Stock idle is set to 650.

secondchance · 10-21-2016

Stock motor with exhaust headers should idle between 650 to 700. I think you have a leak somewhere or IAC is hanging up. Or, could be TB binding somehow.

orthodoct · 10-21-2016

Will swap IAC tomorrow AM. Just looked for vacuum leaks and no obvious suspects. TB operating smoothly throughout range. Replaced all hoses and meticulously rebuilt just about everything when I had the plenum off. Had it so clean that you could eat under there. IAC swap should drop idle. Will advise. IAC was problem previously. Got new replacement from Jerry and it fixed problem. Swapped old one back in and it worked so I left it in. Hindsight 20/20. Should have left replacement from Jerry in! Was a helluva ride today! Had to drive 20 miles in second gear with 4000 rpm idle to keep it below 70 and got behind every stinking log truck in Cumberland County! Go figure. Sitting in town traffic at red lights idling at 4000 rpm with that exhaust system was an experience. One of the red lights was 50 feet from the county courthouse! Good thing that I have operated on half the cops in the county! Was 30 miles from home, so had no choice. Thanks for your help!
Ty

Blue Flame Restorations · 10-22-2016

Sounds like you got it fixed. My in-laws are in Clinton County, KY. Byrdstown TN.

orthodoct · 10-22-2016

Thanks, Brett. Very frustrating, thanks for your help. I have several patients from Byrdstown. I think that I will leave the password where we left it!
You are THE MAN!
Ty

10-21-2016	#1
orthodoct Join Date: Aug 2014 Location: Crossville, TN Posts: 88	VERY high idle Gentlemen: New injectors, clutch, chip from Marc, plenum rebuild, headers, Corsa exhaust 18 months ago. Driving on country road today, passed a "turtle". Idle wouldn't drop below 4000. Had a heck of a time getting to destination! Checked everything roadside that I could, no change idle. Parked car for 1 1/2 hours, restarted, idle 2000 (normally 1100). Drove home, slow to return to idle with clutch in. Had similar problem when rebuilt and was IAC problem. Have a spare from Jerry. Before I tackle it, any other ideas of where to look? Cables are not stuck. Thanks, my friends! Ty Crossville, TN

10-21-2016	#2
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,727	Re: VERY high idle I would look for vacuum leak.

10-21-2016	#3
orthodoct Join Date: Aug 2014 Location: Crossville, TN Posts: 88	Re: VERY high idle Thanks, nothing obvious, but will check further.

10-21-2016	#4
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,711	Re: VERY high idle Is the car stock? NORMAL idle is 1100???? __________________ [SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX

10-21-2016	#5
orthodoct Join Date: Aug 2014 Location: Crossville, TN Posts: 88	Re: VERY high idle Marc Haibeck chip, new injectors from Jerry, Stainless Works ceramic coated headers with cats, Corsa stainless exhaust; everything else stock. 1992; have owned since new, stock idle has always been 1000 or so. Thanks!

10-21-2016	#7
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,727	Re: VERY high idle Stock motor with exhaust headers should idle between 650 to 700. I think you have a leak somewhere or IAC is hanging up. Or, could be TB binding somehow.

10-21-2016	#8
orthodoct Join Date: Aug 2014 Location: Crossville, TN Posts: 88	Re: VERY high idle Will swap IAC tomorrow AM. Just looked for vacuum leaks and no obvious suspects. TB operating smoothly throughout range. Replaced all hoses and meticulously rebuilt just about everything when I had the plenum off. Had it so clean that you could eat under there. IAC swap should drop idle. Will advise. IAC was problem previously. Got new replacement from Jerry and it fixed problem. Swapped old one back in and it worked so I left it in. Hindsight 20/20. Should have left replacement from Jerry in! Was a helluva ride today! Had to drive 20 miles in second gear with 4000 rpm idle to keep it below 70 and got behind every stinking log truck in Cumberland County! Go figure. Sitting in town traffic at red lights idling at 4000 rpm with that exhaust system was an experience. One of the red lights was 50 feet from the county courthouse! Good thing that I have operated on half the cops in the county! Was 30 miles from home, so had no choice. Thanks for your help! Ty

10-22-2016	#9
Blue Flame Restorations Join Date: Feb 2010 Location: Pendleton, IN Posts: 3,909	Re: VERY high idle Sounds like you got it fixed. My in-laws are in Clinton County, KY. Byrdstown TN. __________________ 1988 KOH Prototype EX5023 sold 1990 ZR-1 #444 Convertible 1990 ZR-1 Black #966 1991 ZR-1 Quazar Blue #296 1957 Duntov SS Project Last edited by Blue Flame Restorations; 10-22-2016 at 12:16 AM.

10-22-2016	#10
orthodoct Join Date: Aug 2014 Location: Crossville, TN Posts: 88	Re: VERY high idle Thanks, Brett. Very frustrating, thanks for your help. I have several patients from Byrdstown. I think that I will leave the password where we left it! You are THE MAN! Ty