Is this stuff normal before a tune?
Thread Starter
On The Tree
Joined: May 2003
Posts: 150
Likes: 0
Is this stuff normal before a tune? Hi guys I just put stg2 ls6 style patriot heads on my car with the tsp231/237 cam and longtubes. It will seem like its missing some of the times is that cause of the misfire code the computer is setting? i know the surging is normal but sorta worried about the occational miss. I am fixing to start tuning as soon as i finish the exhaust tommorow thanks guys. chet
TECH Regular
Joined: Nov 2001
Posts: 450
Likes: 0
From: Texas
Check all of the above, check the and make sure all the rockers are tight, I once knew a guy that had a dead miss and drove it 3 hours straight with the rocker arm flapping around not even on the touching the valve 
TECH Addict
Joined: Sep 2003
Posts: 2,065
Likes: 0
From: Atlanta, GA
after i had my cam put in it was triggering a ton of misfires at low rpm, with efilive. It would even throw SES lights at stop lights. Had to have it tuned (and KR desensitized) to fix that. You have to understand these large overlapping cams at low rpm's and the "lope" is gonna cause the crank wheel speedy to vary, which is how the ls1 apparently determines a misfire. If it was misfiring at ALL rpm's that would be one thing, but if you just pay attention to low rpm idle misfire you might drive yourself crazy while the engine is making its lope sound.
Trending Topics
Thread Starter
On The Tree
Joined: May 2003
Posts: 150
Likes: 0
do you think the KR or something in the computer is causing it not to start cause i have looked at grounds/plugs/wires/vaccum leaks and everything and it still wont start. It is getting fuel and it is getting spark it will act like its about to start then wont. Im stumped as of right now. Will running open headers for a few hours burn up the o2 sensors and cause the motor to have fuel puddling and not start? the odd thing about it is that it ran fine last nite and drove it around and it did fine except the misfires and i found a loose pluge wire on that
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 TECH Addict
Joined: Sep 2003
Posts: 2,065
Likes: 0
From: Atlanta, GA
o2 sensors are really hard to burn up man. The car doesn't start in closed-loop mode. It waits a few seconds IIRC when watching my EFILIVE it seemed like even on a warm start it would wait a few before jumping to closed loop mode. If the o2 sensors were dead the ecm would run rich you got gas pouring out the headers?
check your bat voltage make sure its not drained and try part-throttle starting it. Nothing like WOT that didn't work for me when i had cold start issues, seems the gm ecm does something different if you wot start the car.
Find a buddy with a tech2/autotap/efilive to see if theres an ecm issue.
On most ecu's there's a "start" procedure, which then hands itself over to the running (warmup) then switches to closed loop once it reads a strong signal/ECT temp.
I've done some stupid things to bosch o2 sensors like blow hg's on various cars and wash them, or run grossly oversized injectors without a tune, hell even one car ran leaded fuel for a tank and it didn't KILL the o2 sensor. May not be as good as new, but they are tough buggers. Think about all the moisture they must endure over the years..
check your bat voltage make sure its not drained and try part-throttle starting it. Nothing like WOT that didn't work for me when i had cold start issues, seems the gm ecm does something different if you wot start the car.
Find a buddy with a tech2/autotap/efilive to see if theres an ecm issue.
On most ecu's there's a "start" procedure, which then hands itself over to the running (warmup) then switches to closed loop once it reads a strong signal/ECT temp.
I've done some stupid things to bosch o2 sensors like blow hg's on various cars and wash them, or run grossly oversized injectors without a tune, hell even one car ran leaded fuel for a tank and it didn't KILL the o2 sensor. May not be as good as new, but they are tough buggers. Think about all the moisture they must endure over the years..
Thread Starter
On The Tree
Joined: May 2003
Posts: 150
Likes: 0
well i checked the battery voltage its fine and no gas coming out of the headers all grounds are connected all vacums are connected and everything is pluged up. so i am guessing it HAS to be something going on in the ecm right?
Thread Starter
On The Tree
Joined: May 2003
Posts: 150
Likes: 0
thats the odd thing didnt do anything. it was running last nite just a misfire here and there checked it out today and pushed the plug wires and #2 wasnt all the way on and then i got in and started it it started up and when i gave it gas it didnt respond and i continued to try to give it a little gas and it still wouldnt respond to the throttle but it was running then it went dead and wont start now
TECH Addict
Joined: Sep 2003
Posts: 2,065
Likes: 0
From: Atlanta, GA
where ya live? maybe a fellow ls1'er can locally come by and efilive/autotap your ecm to see whats going on?
I'm in atlanta, i'd do it if you were nearby, and im sure some other nice folks would help ya out unless you live in alaska or something lol.
Ask around the local forums. I bet theres some nice folk, there are some cool guys in atlanta.
I'm in atlanta, i'd do it if you were nearby, and im sure some other nice folks would help ya out unless you live in alaska or something lol.
Ask around the local forums. I bet theres some nice folk, there are some cool guys in atlanta.
Pull a plug out and see if it is gas fouled. My car fouled out a set of plugs very quickly when I installed this same setup. Mine ran extremely rich until I tuned it and changed the plugs and now everything is good.