Anyone else experience this? - ZR-1 Net Registry Forums

Dds1990 · 03-09-2017

Being a nice day yesterday I decided take 90 #0106 out for a drive. I live in a rural setting and it ran great. After about 30 minutes I ended up in town and stopped by fast food drive thru. While sitting line the idle started moving from 800 rpm to about 1200 rpm then back to 800 rpm about 4 or 5 times After leaving the drive thru stopped at Shell to top off the tank and drove home without the issue happening again. I did put some stabil in the tank in November, don't know if that could have anything to do with it. It ran great and no SES light.

BigJohn · 03-09-2017

If your car uses premium fuel and you're storing it for only a few months; you really don't need to add stable.
Premium fuel does not break down as quickly as regular.

DRM500RUBYZR-1 · 03-09-2017

I seem to recall that early production 90's were known to have the "hunting idle".
I also recall that there was an update to the prom that resolved or minimized this.
Lastly, I knew many owners of 90's cars that encountered this, and elected to leave it be, except for 1 or 2 where the idle hunted up much higher than 1200, more like 1900.
Sometimes the "cure" is not worth it, if the problem is minor and infrequent.
My 93 has an occasional bout of high or hunting idle, but so transient and rare that I just never bothered to pursue it.
If it begins to happen more often than not, then it should be diagnosed.
Otherwise, let the ghost have his way with your accelerator.

Marty

Dds1990 · 03-09-2017

Thanks, I agree with the ghost thing I have had the car since July and it was the first time,.I can live with that.

Dynomite · 03-09-2017

I think if you were in line and even slightly moving the idle will hang at 1200. If you completely stop for a few seconds then the idle will drop to 800 but if you creep forward may be back to 1200.

Dds1990 · 03-09-2017

That makes sense didn't think of that..Thanks Dyno

lfalzarano · 03-09-2017

You should upgrade you chip to GM release AYBKG for your 1990.
Http://www.zr1specialist.com/HAT%20W...on%20AYBKG.htm

Marc Haibec sells the chip and it addresses problems with idle fluctuation. It solved my 1990 issue also.on

Sent from my iPhone using ZR-1 Net Registry

Dds1990 · 03-09-2017

Thanks for the chip info. I have been wanting to do that, now I have a reason....

billschroeder5842 · 03-09-2017

Quote:

Originally Posted by Dds1990

Thanks for the chip info. I have been wanting to do that, now I have a reason....

I did a Haibeck chip in my 91 and it smoothed out much. It is the best 30 minute install you ever spent.

Racinfan83 · 03-09-2017

X2 on the Haibeck chip. Got rid of that pesky 1-4 shift deal too. That was worth the price on it's own...

03-09-2017	#1
Dds1990 Join Date: Jul 2016 Location: INDIANA Posts: 86	Anyone else experience this? Being a nice day yesterday I decided take 90 #0106 out for a drive. I live in a rural setting and it ran great. After about 30 minutes I ended up in town and stopped by fast food drive thru. While sitting line the idle started moving from 800 rpm to about 1200 rpm then back to 800 rpm about 4 or 5 times After leaving the drive thru stopped at Shell to top off the tank and drove home without the issue happening again. I did put some stabil in the tank in November, don't know if that could have anything to do with it. It ran great and no SES light.

03-09-2017	#2
BigJohn Join Date: Feb 2012 Location: Ledyard,CT Posts: 8,244	Re: Anyone else experience this? If your car uses premium fuel and you're storing it for only a few months; you really don't need to add stable. Premium fuel does not break down as quickly as regular.

03-09-2017	#3
DRM500RUBYZR-1 Join Date: Sep 2008 Location: Mullica Hill, New Jersey Posts: 2,593	Re: Anyone else experience this? I seem to recall that early production 90's were known to have the "hunting idle". I also recall that there was an update to the prom that resolved or minimized this. Lastly, I knew many owners of 90's cars that encountered this, and elected to leave it be, except for 1 or 2 where the idle hunted up much higher than 1200, more like 1900. Sometimes the "cure" is not worth it, if the problem is minor and infrequent. My 93 has an occasional bout of high or hunting idle, but so transient and rare that I just never bothered to pursue it. If it begins to happen more often than not, then it should be diagnosed. Otherwise, let the ghost have his way with your accelerator. Marty

03-09-2017	#4
Dds1990 Join Date: Jul 2016 Location: INDIANA Posts: 86	Re: Anyone else experience this? Thanks, I agree with the ghost thing I have had the car since July and it was the first time,.I can live with that.

03-09-2017	#5
Dynomite Join Date: Aug 2009 Location: South Dakota/California Posts: 3,797	Re: Anyone else experience this? I think if you were in line and even slightly moving the idle will hang at 1200. If you completely stop for a few seconds then the idle will drop to 800 but if you creep forward may be back to 1200. __________________ Left Clickable links -Solutions- LT5 Modifications/Rebuild Tricks Low Mileage ZR-1 Restoration 1990 Corvette (L98) Modifications LT5 Eliminated Systems LT5 Added Systems LT5/ZR-1 Fluids 1995 LT5 SPECIFIC TOP END REBUILD TRICKS

03-09-2017	#7
lfalzarano Join Date: Feb 2011 Location: Clayton, North Carolina Posts: 1,133	Re: Anyone else experience this? You should upgrade you chip to GM release AYBKG for your 1990. Http://www.zr1specialist.com/HAT%20W...on%20AYBKG.htm Marc Haibec sells the chip and it addresses problems with idle fluctuation. It solved my 1990 issue also.on Sent from my iPhone using ZR-1 Net Registry __________________ Lou[COLOR="Red"][B][SIZE="4"][/SIZE][/B][/COLOR]

03-09-2017	#10
Racinfan83 Join Date: Apr 2013 Location: Eastern Missouri Posts: 773	Re: Anyone else experience this? X2 on the Haibeck chip. Got rid of that pesky 1-4 shift deal too. That was worth the price on it's own... __________________ [LEFT][SIGPIC][/SIGPIC][/LEFT] [CENTER][COLOR=Indigo][SIZE=4][I][B] Now Sold 1990 ZR-1 #2093, Black on Black..[/B][/I][/SIZE][/COLOR][/CENTER]