Engine Stumble
Thread Starter
Registered User
Joined: Jun 2007
Posts: 6
Likes: 0
Engine Stumble I have a '99 Z28 6 speed with 70,000 miles, that is stock besides gears and a Lid. The engine stumbles whenever I change gears or accelerate, but then it's fine after that. It does not miss and the check engine light has never come on. I took it to a local dealer and they were no help. A buddy of mine says it sounds like a sensor, but without a code he has no idea either. Anyone have any ideas??? 
Thread Starter
Registered User
Joined: Jun 2007
Posts: 6
Likes: 0
I have had the t-stat and filter replaced. I also had the injectors cleaned. I was told by the local dealer that the plugs didn't need to be changed until 100,000 miles. I just not sure about waiting that long though.
Trending Topics
Oh yeah, change the plugs. They are platinum, which really doesn't perform well. Go with some NGK TR-55's. BTW, do plug #8 from under the car and do that one first. You'll thank me later.
And no more dealer. If you need to go to a mechanic, find one that does LSx stuff. Most dealers know less than the owner of the car, especially if they are an enthusiast. If there isn't a code on the computer which is the case many times, they can't fix it.
And no more dealer. If you need to go to a mechanic, find one that does LSx stuff. Most dealers know less than the owner of the car, especially if they are an enthusiast. If there isn't a code on the computer which is the case many times, they can't fix it.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Thread Starter
Registered User
Joined: Jun 2007
Posts: 6
Likes: 0
They told me since there was not a code the only thing that they could do would be to hunt down the problem at $70 an hour. I have two performance shops about an hour and a half away, Thunder Racing and Futral Motorsports ( Futral being the one that installed my gears), I just don't have the time to get my car down to them. Seeing what I have done so far what should I do next ( after fixing the stumble )?
Last edited by wongduck; Jun 11, 2007 at 09:04 AM.
Catback exhaust and getting yourself HP Tuners. You could pay to have it tuned, but it costs the same if you do it yourself and you can do it whenever you want which is better. Plus lots of guys will help you out if you have questions.
TECH Fanatic
Joined: Aug 2006
Posts: 1,407
Likes: 63
From: Knappa, Oregon
This is very bad advice.
This is very good advice.
Lot of opinions on the right plug. But you have got to change them. Run Search and see what comes up. This is a well discussed issue.
I was told by the local dealer that the plugs didn't need to be changed until 100,000 miles.
Oh yeah, change the plugs.