99 FRC, misfire problems - please help!
Thread Starter
Drifting
Joined: Nov 2003
Posts: 1,898
Likes: 6
From: Sahuarita AZ
Originally Posted by zo6vetteman2003
You pulled the plug ground connectors apart and there wasn't any corrosion at all?
Melting Slicks
Joined: Mar 2005
Posts: 2,252
Likes: 181
From: NE OH
Matt, If you don't get it fixed by this weekend let me know. I've got a compression tester I can drop by. My car is a 99 also, I'm sure between the two of'em we should be able to figure this out.
Thread Starter
Drifting
Joined: Nov 2003
Posts: 1,898
Likes: 6
From: Sahuarita AZ
I'm having some out patient surgery today so I didn't get to test the swap. Muncie, that would be excellent. If you do end up heading down I'll let you take the headers home with you! 
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
Originally Posted by Dan_the_C5_Man
Swaping the coils / injectors on #2 seems reasonable.. Arrgh, wish you had a compression gauge, that would rule our any mechanical issues once and for all.
What does spark plug #2 look like?Robert
Thread Starter
Drifting
Joined: Nov 2003
Posts: 1,898
Likes: 6
From: Sahuarita AZ
Originally Posted by LoneStarFRC
A simple vacuum gauge would help too. What does spark plug #2 look like?
Robert
What does spark plug #2 look like?Robert
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
I'm surprised your not throwing a P0300 code and a flashing CEL too. Too much fuel, if not corrected quickly enough, is really bad for catalytic converters. Not to mention the whole cylinder "washdown" thing too.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Drifting
Joined: Nov 2003
Posts: 1,898
Likes: 6
From: Sahuarita AZ
Originally Posted by LoneStarFRC
I'm surprised your not throwing a P0300 code and a flashing CEL too. Too much fuel, if not corrected quickly enough, is really bad for catalytic converters. Not to mention the whole cylinder "washdown" thing too.
Melting Slicks
Joined: Mar 2005
Posts: 2,252
Likes: 181
From: NE OH
If you haven't already, you should take a second to read the troubleshooting tree for code P0300 here: http://www.gearchatter.com/viewtopic10049.php
Also, from what I can recall, if the PCM detects a specific cylinder is misfiring the code P0300 will increment based upon the cylinder. For example if cylinder #4 is misfiring you'll get code P0304, code P0307 for cylinder 7 etc.
Based upon this info, I'm inclinded to believe you have a single problem affecting all cylinders.
Also, from what I can recall, if the PCM detects a specific cylinder is misfiring the code P0300 will increment based upon the cylinder. For example if cylinder #4 is misfiring you'll get code P0304, code P0307 for cylinder 7 etc.
Based upon this info, I'm inclinded to believe you have a single problem affecting all cylinders.
Navigator
Joined: Aug 2005
Posts: 9
Likes: 0
From: El Paso TX
misfire
This sounds a little like a problem I had with my 03-Z06. This misfire came and went and also changed sides (banks). A member on this forum suggested that the wiring harness to the injectors might be damaged, that was his problem. After telling this to the warranty dealer, they dismissed my sugestion for 6 months. When all else failed, they tried replacing the harness and my Vette has run great since then.
Thread Starter
Drifting
Joined: Nov 2003
Posts: 1,898
Likes: 6
From: Sahuarita AZ
Originally Posted by muevet
This sounds a little like a problem I had with my 03-Z06. This misfire came and went and also changed sides (banks). A member on this forum suggested that the wiring harness to the injectors might be damaged, that was his problem. After telling this to the warranty dealer, they dismissed my sugestion for 6 months. When all else failed, they tried replacing the harness and my Vette has run great since then.
Navigator
Joined: Aug 2005
Posts: 9
Likes: 0
From: El Paso TX
wiring harness
Here is what they told me. They can check for the miss and charge the time, but they had to get factory approval to order and replace the part under warranty. The fix was quick once "they" found the problem.
Le Mans Master
Joined: Sep 2003
Posts: 6,276
Likes: 227
From: Farmington CT
Cruise-In VII Veteran
Originally Posted by torchredfrc
I've visually inspected the wires and will I don't believe they are bad I've still got my fingers crossed that they are not bad. Do you know what all was replaced when they redid your wiring? It would be quite a job if you had to replace the entire wire harness.
Thread Starter
Drifting
Joined: Nov 2003
Posts: 1,898
Likes: 6
From: Sahuarita AZ
Originally Posted by Dan_the_C5_Man
So what ever happened with the parts swapping exercise?
Next step... since muncie21 went home with my headers, I'm ordering another set of LG Pro LT's (with cats this time) on Monday and I'm going to see if they will weld in a extra O2 bung so I can run 2 stock narrow band sensors as well as my wideband w/o emulation. I will also be purchasing 2 new narrowband O2 sensors since my driver's side sensor now looks lazy and isn't switching very well.
Melting Slicks
Joined: Mar 2005
Posts: 2,252
Likes: 181
From: NE OH
BTW, we did a compression check on the suspect cylinder (#2) and it's adjacent brother, #4. Both were around 155 or so.
I will pose this question on the HPT forum, but I figure I'll start here first as I'm sure there are people here that are interested also. Here's the question:
What exactly does the cylinder balance test do/so?
When torchredfrc did this test, it showed cylinder #2 as being significantly different than the rest---~60 vs. ~90-100'ish for the rest. But in subsequent testing we could not find any issues with that cylinder. Coil packs were changed, ignition wires were ohm'ed, spark plugs checked, injectors changed, compression tested, etc......
I will pose this question on the HPT forum, but I figure I'll start here first as I'm sure there are people here that are interested also. Here's the question:
What exactly does the cylinder balance test do/so?
When torchredfrc did this test, it showed cylinder #2 as being significantly different than the rest---~60 vs. ~90-100'ish for the rest. But in subsequent testing we could not find any issues with that cylinder. Coil packs were changed, ignition wires were ohm'ed, spark plugs checked, injectors changed, compression tested, etc......