Intermittent hesitation at light throttle - ZR-1 Net Registry Forums

tiegsd · 08-18-2019

It feels like I'm bouncing my foot lightly on the throttle, but I'm actually holding it steady. Then after 30 sec or so it'll stop and the service engine light will come on at the same time. Everything is fine when the service engine light is on. After a minute or two the svc eng light will go out, then the intermittent hesitation may or may not come back. When it does, it's the same process.

Anyone seen this before? Injectors are new, only 1 year old. Seems to be fine when I open the throttle more. Thought at first dead spot on throttle position sensor, but then it's smooth with the svc eng light on?

Doesn't keep me from driving the car, just a minor annoyance at the moment. Would like to track it down before it's not minor anymore though.

Any input appreciated.

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Hib Halverson · 08-18-2019

What fault code is stored?

XfireZ51 · 08-18-2019

It may be going momentarily lean.

Paul Workman · 08-19-2019

Hib beat me toit. See what code(s) it may have stored...is the FIRST step to see what is going on. The ZR-1 is OBD-1, which most auto parts stores can read, as long as they can read OBD-1.

Ccmano · 08-19-2019

Agreed, codes first. If you don’t have equipment to read the codes (Tech1 or such) here’s instructions on how to do it with a paper clip.
H

http://www.zr1specialist.com/HAT%20W...0Info/aldl.htm

lfalzarano · 08-19-2019

If your eyes can see close up as you squeeze under the driver’s side under the dash in The footwell...

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tiegsd · 08-24-2019

Okay, makes sense. Never done the code reading thing on the ZR-1 before, but I have the service manual. I'll do that and see what pops up.

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08-18-2019	#1
tiegsd Join Date: Jul 2017 Location: West Chester, PA Posts: 380	Intermittent hesitation at light throttle It feels like I'm bouncing my foot lightly on the throttle, but I'm actually holding it steady. Then after 30 sec or so it'll stop and the service engine light will come on at the same time. Everything is fine when the service engine light is on. After a minute or two the svc eng light will go out, then the intermittent hesitation may or may not come back. When it does, it's the same process. Anyone seen this before? Injectors are new, only 1 year old. Seems to be fine when I open the throttle more. Thought at first dead spot on throttle position sensor, but then it's smooth with the svc eng light on? Doesn't keep me from driving the car, just a minor annoyance at the moment. Would like to track it down before it's not minor anymore though. Any input appreciated. Sent from my SM-N920V using ZR-1 Net Registry mobile app __________________ 1990 Black/Black ZR-1 #1155 1993 White/Red coupe (Regrettably sold)

08-18-2019	#2
Hib Halverson Join Date: Jun 2005 Location: CenCoast California Posts: 899	Re: Intermittent hesitation at light throttle What fault code is stored? __________________ Hib Halverson Technical Writer former owner 95 VIN 0140 current owner 19 VIN 1878

08-18-2019	#3
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,711	Re: Intermittent hesitation at light throttle It may be going momentarily lean. __________________ [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

08-19-2019	#4
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,493	Re: Intermittent hesitation at light throttle Hib beat me toit. See what code(s) it may have stored...is the FIRST step to see what is going on. The ZR-1 is OBD-1, which most auto parts stores can read, as long as they can read OBD-1. __________________ 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

08-19-2019	#5
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: Intermittent hesitation at light throttle Agreed, codes first. If you don’t have equipment to read the codes (Tech1 or such) here’s instructions on how to do it with a paper clip. H http://www.zr1specialist.com/HAT%20W...0Info/aldl.htm __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold.

08-19-2019	#6
lfalzarano Join Date: Feb 2011 Location: Clayton, North Carolina Posts: 1,133	Re: Intermittent hesitation at light throttle If your eyes can see close up as you squeeze under the driver’s side under the dash in The footwell... Sent from my iPhone using ZR-1 Net Registry __________________ Lou[COLOR="Red"][B][SIZE="4"][/SIZE][/B][/COLOR]

08-24-2019	#7
tiegsd Join Date: Jul 2017 Location: West Chester, PA Posts: 380	Re: Intermittent hesitation at light throttle Okay, makes sense. Never done the code reading thing on the ZR-1 before, but I have the service manual. I'll do that and see what pops up. Sent from my SM-N920V using ZR-1 Net Registry mobile app __________________ 1990 Black/Black ZR-1 #1155 1993 White/Red coupe (Regrettably sold)