Idle problem when stopped
Thread Starter
Pro
Joined: Nov 2001
Posts: 655
Likes: 0
From: San Diego California
Idle problem when stopped
when the vette is cold it seem to idle fine.
when it warms up or maybe just after it's been running a while it starts acting funny.
when i stop the idle is fine for about 20 seconds the it seems to drop a few hundred rpms almost to a stall.
i have a code reader and no codes came up.
does anyone have an idea?
'90 L98 coupe
when it warms up or maybe just after it's been running a while it starts acting funny.
when i stop the idle is fine for about 20 seconds the it seems to drop a few hundred rpms almost to a stall.
i have a code reader and no codes came up.
does anyone have an idea?
'90 L98 coupe
Melting Slicks
Joined: Jun 2004
Posts: 3,032
Likes: 4
Hmm... You should take a look at this thread...
http://forums.corvetteforum.com/showthread.php?t=922612
http://forums.corvetteforum.com/showthread.php?t=922612
Thread Starter
Pro
Joined: Nov 2001
Posts: 655
Likes: 0
From: San Diego California
thanks guys i'll check it out. it shouldn't be the O2 sensor I replaced it a few months ago. IAC on the other hand has been with the car for 7yrs now...oops
sorry Mickey but i'm in the middle of moving no DSL and dial-up is way to slow to do a search. thanks !!!
sorry Mickey but i'm in the middle of moving no DSL and dial-up is way to slow to do a search. thanks !!!
Team Owner
Joined: Oct 2000
Posts: 96,443
Likes: 9
From: Fort Knox, KY
Cruise-In IV Veteran
Cruise-In VI Veteran
Cruise-In VII Veteran
Cruise-In VIII Veteran
Check your PCV valve, too. I replaced mine about three weeks ago and it was either O.E.M. or seriously way past it's service life. It was embarrassingly discolored and partially clogged up.
My base idle's much better now. It's just one of those things that's easy to overlook...and even easier to replace.
My base idle's much better now. It's just one of those things that's easy to overlook...and even easier to replace.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
2027 Corvette vs The World: Every Model vs Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)
Joe Kucinski
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!
Michael S. Palmer
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!
Joe Kucinski
Thread Starter
Pro
Joined: Nov 2001
Posts: 655
Likes: 0
From: San Diego California
how do you reset base idle? i can't see where you tighten the screw by the throttle. I replaced the IAC and am still getting the problem. will try the pvc next and a can of cleaner
Melting Slicks
Joined: Jun 2004
Posts: 3,032
Likes: 4
Originally Posted by eddieL98
how do you reset base idle? i can't see where you tighten the screw by the throttle. I replaced the IAC and am still getting the problem. will try the pvc next and a can of cleaner
Thread Starter
Pro
Joined: Nov 2001
Posts: 655
Likes: 0
From: San Diego California
ok just rest the IAC. found it in the service manual. still having problem.
car starts fine idles at about 900rpm
warms up and drops to about 700
i place it in drive it drops to 650 or so
when I give it gas no problem no hesitation
when I let it idle it surges low
I trun the a/c @ idles car dies too much load.
oil pressure low ar idle but i guess that's due to low idle
runs normal at speed.
car starts fine idles at about 900rpm
warms up and drops to about 700
i place it in drive it drops to 650 or so
when I give it gas no problem no hesitation
when I let it idle it surges low
I trun the a/c @ idles car dies too much load.
oil pressure low ar idle but i guess that's due to low idle
runs normal at speed.
Melting Slicks
Joined: Jun 2004
Posts: 3,032
Likes: 4
Originally Posted by eddieL98
when I let it idle it surges low
and you're right- low idle will cause low oil pressure...
Pro
Joined: Sep 2002
Posts: 609
Likes: 0
From: Buford Georgia
I have idle problems with my 89'. Runs fine when cold them once it warms up I get surges and rough running at idle. Used an Ohm meter on the injectors and found 3 that were reading bad. 5 of the injectors were reading 17.4 ohms but 1 reading 3.4, another reading 10.2 and the 3rd reading 14.1....gonna replace injectors now.
Worth a shot.
Worth a shot.
Thread Starter
Pro
Joined: Nov 2001
Posts: 655
Likes: 0
From: San Diego California
took car to the shop to test. they said it could be the EGR since it's not holding pressure or the injectors. the car is running rich making it stall at idle.
I have accell injector not sure what the specs as in ohm goes but they are at 15ohm. will have to go to the site or call them to check.
going to pull the egr since I already have one.
actually I have a new intake setup in storage I never got around to installing. since i have to pull them might as well replace it.
high flow intake & runners/ plenum.
if the injectors turn out to be bad any recomendations??
I have accell injector not sure what the specs as in ohm goes but they are at 15ohm. will have to go to the site or call them to check.
going to pull the egr since I already have one.
actually I have a new intake setup in storage I never got around to installing. since i have to pull them might as well replace it.
high flow intake & runners/ plenum.
if the injectors turn out to be bad any recomendations??
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
The injectors look ok - unless one is leaking - at least the resistance is normal. The fact that it stalls when you turn on the a/c may be an ECM problem. You need to hook up a scanner and monitor the a/c request signal and IAC counts. The scan should show a "Yes" when the compressor clicks on and the IAC counts should increase. If not, the ECM or the wiring is funky, particularly if you've cleaned or replaced the IAC. You should also check fuel pressure and vacuum. I'm surprised that the mechanic didn't do this to narrow down what's going on. Did he explain what he meant by the EGR not holding pressure? Manifold pressure or vacuum should keep it closed at idle but without taking it off to inspect the pintle and the manifold seat, it's difficult to tell.
Racer
Joined: May 2001
Posts: 472
Likes: 0
From: Tampa Bay Area
How does the computer know if the A/C is on? Does the wiring harness connect to the compressor or something? Can you buy that piece? My compressor is from an 80 Vette so it doesn't have anything to connect to the computer.
thanks
thanks
