08-18-2016 | #1 |
Join Date: Jul 2016
Location: INDIANA
Posts: 86
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High Idle
Just recently got the secondarys working on my 1990. I replaced the rubber PCV connector and the secondarys began working and are still working. I am have a high idle ..about 1500 rpm then it will drop to 900 rpm after being stopped for about 5-10 seconds or so. After replacing the PCV connector and first start up I did have a backfire and I did check the MAP sensor vacuum connection and it was fine. Im clear it could be a vacuum leak but where since the secondarys are working?? Could it be a O2 sensor?? As always any and all help will be greatly appreciated....
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08-18-2016 | #2 |
Join Date: Feb 2016
Location: Carterville Illinois
Posts: 849
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Re: High Idle
It sounds like a vacuum leak, maybe under the plenum. And are your injectors original?
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08-18-2016 | #3 |
Join Date: May 2007
Location: Peoria, AZ
Posts: 9,154
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Re: High Idle
If you have checked the MAP hose that's is connected to the MAP Sensor on the rear of the plenum as stated it sounds like the PVC hose or another vacuum hose under the Plenum blew off with that backfire. You will need to pull the plenum to get to it. GC
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GOLDCYLON - 91 ZR-1 #2014 GOLDCYLON - 90 ZR-1 #2794, 4L60e (Formerly Schrade's) GOLDCYLON - 11 CTS-V Arizona State Director 91 WHITE/BLACK #2014. 380 P&P&PCed,Ported Heads, Jeal Long tubes, Corsa Exhaust/FIKSE FM-5s /LED TLs, LED Headlights, Front Wilwood 6 piston narrowlite calipers and rear Wilwood caliper street shop mod,CNCed Coolant Pipes,TPI Cvr,Filter cover,Stainless Bolts, DRM/DOM PROM /ZFDOC mod build #102,DRLs,BMAD with stainless Debris Screen,Coplan Air Blaster, Pioneer APP Radio 4,Brey-Krause HB,Sub Bar,Fire extinguisher seat mount,DRM Coilovers,LEDs everywhere,Compass mirror (orange),V1 DIC hidden display, Homelink sun visor, Carbon Fiber top x3 and APSIS Carbon Fiber interior, APSIS CF Steering Wheel/NAPA Leather, Banski trailing arms, Guldstrand front suspension,urethane bushings from Prothane (total suspension) ZFDoc drive shaft safety loop, raptor shift light (orange),AO engineering louver front plate, Console seat cushion, 96CE seats with black custom Sheepskins, ss billet catch can,Viper remote entry/alarm,Cragar Rear Louvers,LED side louver lights, Dewitts Radiator with SPAL fans and a Woods 160 T-Stat 90 RED/BLACK #2794. 4L60e Automatic Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless Headers, Corsa Exhaust, SAN Secondaries and Haibeck PROM, Exotic Muscle Coil overs, LED Interior Lights, LED Tail Lights, LED Headlights, 94 Sport seats with black custom Sheepskins , Cragar rear louvers, GS Front calipers, Banski Trailing arms, APSIS Carbon Fiber steering wheel, Front and Rear Baer Eradispeeds, DRLs, Guldstrand front suspension,urethane bushings from Prothane (total suspension), Dewitt's Raditor with Dual SPAL fans and a Haibeck 170 T-Stat 11 RED/GREY CTS-V |
08-18-2016 | #4 |
Join Date: Jul 2016
Location: INDIANA
Posts: 86
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Re: High Idle
No they were replaced in June.....There was a vacuum leak at the PCV connection that would not allow the secondarys to work which was fixed. I was under the assumption if the was a vacuum leak under the plenum the secondarys would again not be working...?????
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08-18-2016 | #5 |
Join Date: Jul 2016
Location: INDIANA
Posts: 86
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Re: High Idle
I guess a better question would be where would a vacuum leak causing high idle be at that would not effect the secondarys working properly? The car runs great just when I come to a stop it idles at 1500 rpms then drops to 900 rpms...
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08-18-2016 | #6 | |
Join Date: May 2007
Location: Peoria, AZ
Posts: 9,154
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Re: High Idle
Quote:
Does the idle swing from high to low. Or is it high and then the drops to low and remains.
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GOLDCYLON - 91 ZR-1 #2014 GOLDCYLON - 90 ZR-1 #2794, 4L60e (Formerly Schrade's) GOLDCYLON - 11 CTS-V Arizona State Director 91 WHITE/BLACK #2014. 380 P&P&PCed,Ported Heads, Jeal Long tubes, Corsa Exhaust/FIKSE FM-5s /LED TLs, LED Headlights, Front Wilwood 6 piston narrowlite calipers and rear Wilwood caliper street shop mod,CNCed Coolant Pipes,TPI Cvr,Filter cover,Stainless Bolts, DRM/DOM PROM /ZFDOC mod build #102,DRLs,BMAD with stainless Debris Screen,Coplan Air Blaster, Pioneer APP Radio 4,Brey-Krause HB,Sub Bar,Fire extinguisher seat mount,DRM Coilovers,LEDs everywhere,Compass mirror (orange),V1 DIC hidden display, Homelink sun visor, Carbon Fiber top x3 and APSIS Carbon Fiber interior, APSIS CF Steering Wheel/NAPA Leather, Banski trailing arms, Guldstrand front suspension,urethane bushings from Prothane (total suspension) ZFDoc drive shaft safety loop, raptor shift light (orange),AO engineering louver front plate, Console seat cushion, 96CE seats with black custom Sheepskins, ss billet catch can,Viper remote entry/alarm,Cragar Rear Louvers,LED side louver lights, Dewitts Radiator with SPAL fans and a Woods 160 T-Stat 90 RED/BLACK #2794. 4L60e Automatic Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless Headers, Corsa Exhaust, SAN Secondaries and Haibeck PROM, Exotic Muscle Coil overs, LED Interior Lights, LED Tail Lights, LED Headlights, 94 Sport seats with black custom Sheepskins , Cragar rear louvers, GS Front calipers, Banski Trailing arms, APSIS Carbon Fiber steering wheel, Front and Rear Baer Eradispeeds, DRLs, Guldstrand front suspension,urethane bushings from Prothane (total suspension), Dewitt's Raditor with Dual SPAL fans and a Haibeck 170 T-Stat 11 RED/GREY CTS-V Last edited by GOLDCYLON; 08-18-2016 at 10:07 AM. |
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08-18-2016 | #7 |
Join Date: May 2007
Location: Chicagoland, IL
Posts: 9,699
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Re: High Idle
If the idle drops, it may not be a vacuum leak. I see u have a 90 which has a mod to the calibration addressing the Decel Fuel Cutoff routine that does what u are describing.
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[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 |
08-18-2016 | #8 | |
Join Date: Nov 2007
Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri
Posts: 6,493
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Re: High Idle
Quote:
Someone (Marc?) correct me if I'm wrong, but I believe that is SOP for a 1990 car. Mine has always done that when coming ro a stop fron hwy speeds, as well as a high idle immediately upon starting that lasts 3-5 seconds before settling down to 850ish. I read somewhere that this "charming" little feature was adderessed in the 91+ calibrations - Ami's 91 does not do it (tuned by Pete, if that matters). I've learned to live with it. Nothing to do on startup but wait a few seconds. It gets the oil circulating I guess (and my Ford F150 does the exact same thing on startup). The high idle, coming down to a stop from hwy speed, does not happen IF I down-shift and engine brake just a little. But, foot off the gas, clutch depressed, and come to a quick stop - I get a high idle for 2-3 seconds. Initial startup 3-5 seconds @ 2000 rpm; quick stop from speed = 1500 rpm for 2-3 seconds is typical for my 1990 since 2007 when I bought it...
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Good carz, good food, good friendz = the best of timez! 90 #1202 "FBI" top end ported & relieved Cam timing by "Pete the Greek" Sans secondaries Chip & dyno tuning by Haibeck Automotive SW headers, X-pipe, MF muffs Former Secretary, ZR-1 Net Registry |
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08-18-2016 | #9 |
Join Date: Jul 2016
Location: INDIANA
Posts: 86
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Re: High Idle
Swings from high to low the stays. Sounds exactly like Pauls 1990...If I downshift it does not do it. Secondarys are working fine. Sounds like its just a 1990 thing...I can live with it...love the car...
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08-18-2016 | #10 |
Join Date: May 2007
Location: Peoria, AZ
Posts: 9,154
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Re: High Idle
Yep that's normal the way I read it the cars idle was swinging high to low. Mostly high
__________________
GOLDCYLON - 91 ZR-1 #2014 GOLDCYLON - 90 ZR-1 #2794, 4L60e (Formerly Schrade's) GOLDCYLON - 11 CTS-V Arizona State Director 91 WHITE/BLACK #2014. 380 P&P&PCed,Ported Heads, Jeal Long tubes, Corsa Exhaust/FIKSE FM-5s /LED TLs, LED Headlights, Front Wilwood 6 piston narrowlite calipers and rear Wilwood caliper street shop mod,CNCed Coolant Pipes,TPI Cvr,Filter cover,Stainless Bolts, DRM/DOM PROM /ZFDOC mod build #102,DRLs,BMAD with stainless Debris Screen,Coplan Air Blaster, Pioneer APP Radio 4,Brey-Krause HB,Sub Bar,Fire extinguisher seat mount,DRM Coilovers,LEDs everywhere,Compass mirror (orange),V1 DIC hidden display, Homelink sun visor, Carbon Fiber top x3 and APSIS Carbon Fiber interior, APSIS CF Steering Wheel/NAPA Leather, Banski trailing arms, Guldstrand front suspension,urethane bushings from Prothane (total suspension) ZFDoc drive shaft safety loop, raptor shift light (orange),AO engineering louver front plate, Console seat cushion, 96CE seats with black custom Sheepskins, ss billet catch can,Viper remote entry/alarm,Cragar Rear Louvers,LED side louver lights, Dewitts Radiator with SPAL fans and a Woods 160 T-Stat 90 RED/BLACK #2794. 4L60e Automatic Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless Headers, Corsa Exhaust, SAN Secondaries and Haibeck PROM, Exotic Muscle Coil overs, LED Interior Lights, LED Tail Lights, LED Headlights, 94 Sport seats with black custom Sheepskins , Cragar rear louvers, GS Front calipers, Banski Trailing arms, APSIS Carbon Fiber steering wheel, Front and Rear Baer Eradispeeds, DRLs, Guldstrand front suspension,urethane bushings from Prothane (total suspension), Dewitt's Raditor with Dual SPAL fans and a Haibeck 170 T-Stat 11 RED/GREY CTS-V |
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