Intermittant Miss at Idle only. No Codes.
Thread Starter
Advanced
Joined: Dec 2001
Posts: 95
Likes: 0
From: Allen Texas
Intermittant Miss at Idle only. No Codes.
2000 Coupe AT 150K, mostly stock, stock tune.
Car misses at idle only intermittantly. Just replaced plugs and wires. Checked and double checked. If you hold the RPM's up a little it never misses. APP or TAC ? How to check ? Other ideas. Engine performs fine at all other conditions. Only can detect miss at idle and it does not always do it.
Car misses at idle only intermittantly. Just replaced plugs and wires. Checked and double checked. If you hold the RPM's up a little it never misses. APP or TAC ? How to check ? Other ideas. Engine performs fine at all other conditions. Only can detect miss at idle and it does not always do it.
Team Owner
Joined: May 2001
Posts: 36,836
Likes: 244
From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
Not a "miss" or the pcm would be kicking codes. It's more a function of the camshaft duration/lift, etc than anything else. Not uncommon to see slight rpm variations and "feel" a slight, occasional SOTP vibration.
Racer
Joined: Mar 2010
Posts: 252
Likes: 0
From: Clarkesville GA
Oldtimer
When I bought my '98 it did that...Just at idle and not all the time.
Found that it had a set of E3 plugs in it and when I replaced them with NKG-55s the problem went away never to return..
Julian
Found that it had a set of E3 plugs in it and when I replaced them with NKG-55s the problem went away never to return..
Julian
Thread Starter
Advanced
Joined: Dec 2001
Posts: 95
Likes: 0
From: Allen Texas
Definetly a miss. You can feel the engine jerk it is very obvious. Not a rpm fluctuation. I have replaced the PVC and been thru all the vaccum lines and fittings. Before was throwing codes for too lean on both banks. Found the little rubber boot to the thottle body had a hole in it. MAF has been cleaned also. Will focus on the injectors now. Plan to pull clean all connections and run injector cleaner thru them. I had a similar problem on another car some time back and found a leaking injector. Is there an easy way to check without pulling each injector ? Pressurize the fuel rail ?
Team Owner
Joined: May 2001
Posts: 36,836
Likes: 244
From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
Definetly a miss. You can feel the engine jerk it is very obvious. Not a rpm fluctuation. I have replaced the PVC and been thru all the vaccum lines and fittings. Before was throwing codes for too lean on both banks. Found the little rubber boot to the thottle body had a hole in it. MAF has been cleaned also. Will focus on the injectors now. Plan to pull clean all connections and run injector cleaner thru them. I had a similar problem on another car some time back and found a leaking injector. Is there an easy way to check without pulling each injector ? Pressurize the fuel rail ?
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its 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
Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 328
From: CA.
St. Jude Donor '13-'14-'15
What brand and part # of plug and which wires did you get ??
what did you gap them at ??
TR5 or TR55 gapped at .040 seems to work the best---Also on some wires the boots on the colis are soo thick they don't snap on--Make sure you feel a click or snap when you intall them--On some boots they seal so well to the coil towers that whn installed the air can't escape insde the boot-- (MSD wire known for this) To fix just lay a small wire or zip tie on the inside of the boot while installing--then pull it out after you hear the click--this will let the air escape
ALSO a bank running LEAN means that the ECM is ADDING fuel----It could be adding so much that breifly it becomes too rich fouls and misfires-
Best way to clean injectors and intake is to use Seafoam--follow instructions on can--
what did you gap them at ??
TR5 or TR55 gapped at .040 seems to work the best---Also on some wires the boots on the colis are soo thick they don't snap on--Make sure you feel a click or snap when you intall them--On some boots they seal so well to the coil towers that whn installed the air can't escape insde the boot-- (MSD wire known for this) To fix just lay a small wire or zip tie on the inside of the boot while installing--then pull it out after you hear the click--this will let the air escape
ALSO a bank running LEAN means that the ECM is ADDING fuel----It could be adding so much that breifly it becomes too rich fouls and misfires-
Best way to clean injectors and intake is to use Seafoam--follow instructions on can--
Thread Starter
Advanced
Joined: Dec 2001
Posts: 95
Likes: 0
From: Allen Texas
Removed all injector connectors and cleaned with electrical contact cleaner. Same for TPS connector.
With Engine running rotated and sprayed each injector seal with WD 40 to check for leaks. Nothing found.
Put some concentrated injector cleaner in about 3/4 a tank of fuel. Drove on HWY with a little WOT time.
So far smooth as ever. Will repost if it starts acting up again.
Thanks for the replies.
With Engine running rotated and sprayed each injector seal with WD 40 to check for leaks. Nothing found.
Put some concentrated injector cleaner in about 3/4 a tank of fuel. Drove on HWY with a little WOT time.
So far smooth as ever. Will repost if it starts acting up again.
Thanks for the replies.
