Took computer out now car doesnt run right
Took computer out now car doesnt run right I took my computer out of my car today when i put it back in it was backfiring and idling rough. Ihad the car dyno tuned at Cartek and they told me that i was able to disconnect the battery and i wouldnt lose the tune. Also i had the diablo tune in the car before it was tuned, i tried putting the tune in but it ran worse, do i need to get it dyno tuned again? any help is greatly appreciated. 
TECH Senior Member
Joined: Nov 2001
Posts: 7,036
Likes: 1
From: Lake Zurich, IL
you won't lose the tune by removing the PCM or disconnecting the battery.. you're prolly going through the Idle relearn (there are parameters the PCM learns from being in use) Once the car learns how to idle again should be fine (couple driving cycles and it should have everything pretty well relearned)
TECH Addict
Joined: Feb 2004
Posts: 2,826
Likes: 0
Speedo and speed limiter are not learned, they are programmed in. They won't change (unless the car is tuned). But the canned Predator tune...that should have overwritten a lot of what they had done, which would make your car run like crap. Any tuning that is done to your PCM is permanent (flash memory stays there, power or no power), unless it is overwritten (by something like a Predator, or the dealership, or another tune). It is normal for a car that was tuned to run like crap for awhile until things like LTFTs are re-learned. Especially with the crap these people are passing off as "professional tunes". You can pull the battery on my PCM and plug it back in, and you would never know the difference.
so i have to get the car tuned again? the rev limiter was set to 6800 and the predator will only go 6600, i can change the speedo with the diablo. I took the diablo tune out will it still mess up what Cartek did?
TECH Addict
Joined: Feb 2004
Posts: 2,826
Likes: 0
Originally Posted by sickss228
so i have to get the car tuned again? the rev limiter was set to 6800 and the predator will only go 6600, i can change the speedo with the diablo. I took the diablo tune out will it still mess up what Cartek did?
Trending Topics
How do I retrieve the tune that Cartek did if i loaded the predator while my car was stock? Wont it keep loading the stock tune, i havent touched it until yesterday thats when all the problems started, the predator didnt say it was saving the tune that was in the car, so iguess it thinks i have the stock tune still?? thanks for the help
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 Senior Member
Joined: Nov 2001
Posts: 7,036
Likes: 1
From: Lake Zurich, IL
sounds like the predator is overwriting the calibration section of the PCM w/its own values... and since it only backs up the PCM on initial tune... I'm afraid your cartek tune may be gone I read this over briefly the other night... but didn't see that you applied your predator tune on it ... the initial poor idling characteristics was probably idle relearn... but when you reflashed with the predator .. sounds like it overwrote the calibration section of the PCM
Thanks for all the help, looks like I have to get it tuned again, I am a Marine stationed at Camp Lejuene NC, should I wait until i go on leave around christmas and get it tuned at Cartek or is there any good shops in NC, Cartek is an excellent shop but if I can find a shop around here I'll probably do that.
Because I bought the car to Cartek with the diablo tune in it, when i was truing to sell the programmer it said it was still locked to my car so i restored the stock setting, then it wasnt idling right so i put the tune back in it and it ran worse, so i restored it again, it drives good still, just the idle, speedo, and rev limiter is off, do you thinkthat i might have just erased the speedo cal, and rev limiter, I think the pcm is still on the learning curve for the idle??
TECH Addict
Joined: Feb 2004
Posts: 2,826
Likes: 0
Originally Posted by horist
sounds like the predator is overwriting the calibration section of the PCM w/its own values... and since it only backs up the PCM on initial tune... I'm afraid your cartek tune may be gone I read this over briefly the other night... but didn't see that you applied your predator tune on it ... the initial poor idling characteristics was probably idle relearn... but when you reflashed with the predator .. sounds like it overwrote the calibration section of the PCM