Got Colder...Need a Retune??

**Wesman** · 10-12-2007, 03:39 PM

Well I had my car tuned by Harris Speed Works in Warminster, PA a couple weeks ago. They did a great job - car put down 341WHP, and it drove great afterwards, up until now.

It was well over 80 degrees when I had the car tuned. The tempurature dropped down to between 50 and 60 degrees for the first time today, and all of a sudden the car feels like a dog. Its got none of the get up and go that it had before, and it feels like like I lost a bunch of power/torque.

For example: Before, I could shift at 2,500 to 3,000RPM at part throttle and the thing would pull great, grab the next gear, same thing - the power delivery was so smooth. Now, I do the same thing today, it barely pulls at half throttle at the same RPM's, and then if I put the clutch in to grab the next gear, the rev's jump way up, like its loading up on fuel.

Any ideas from you tuner pros of what couse be causing this?? Do you think disconnecting the battery (for 15 mins or whatever) would reset the computer for the colder weather??

**sunsetorangess** · 10-14-2007, 06:43 PM

The tune should be fine, Dis-connecting the battery will not reset your tune. You can take it back to Hsw but i doubt its your tune. Sounds like a slipping clutch?
J

**Wesman** · 10-14-2007, 07:49 PM

Originally Posted by sunsetorangess

The tune should be fine, Dis-connecting the battery will not reset your tune. You can take it back to Hsw but i doubt its your tune. Sounds like a slipping clutch?
J

Well I actually ended up disconnecting the battery to reset the ECU (not the tune) Friday night. Took it to work Saturday morning, and it drove perfectly, just as it did before it got cold. Guess the ECU just needed to readjust to the colder air. Thanks for the response though.

**sunsetorangess** · 10-14-2007, 08:15 PM

Originally Posted by Wesman

Well I actually ended up disconnecting the battery to reset the ECU (not the tune) Friday night. Took it to work Saturday morning, and it drove perfectly, just as it did before it got cold. Guess the ECU just needed to readjust to the colder air. Thanks for the response though.

Lol, Goodstuff, It was just having a moment.
J

**mrr23** · 10-14-2007, 09:23 PM

basically you just did a reset fuel trims. it's relearning the fuel trims now.

**{FzS}BlacKMagicK** · 10-14-2007, 11:22 PM

It would seem to be a really good idea then to disconnect the battery with a seasonal temp change, whether up or down. Is there a certain length of time it has to be disconnected for?

Also, could someone explain how your not messing with the tune, yet the car is relearning fuel trims, isn't that something that is set when you have a tune done? Does the car have a backup battery for the brain or is it some kind of hard memory that would keep a tune?

**98formy** · 10-15-2007, 05:52 AM

The computer stores the hard info to operate in flash memory, so the battery being disconnected does not effect it.

**Wesman** · 10-15-2007, 02:00 PM

Originally Posted by mrr23

basically you just did a reset fuel trims. it's relearning the fuel trims now.

Ok cool, I figured there had to be an explaination.

**9t8z28** · 10-15-2007, 02:56 PM

SWEET! I didn't know you went to HSW!

**Wesman** · 10-15-2007, 03:25 PM

Originally Posted by 9t8z28

SWEET! I didn't know you went to HSW!

Oh yea man I should have PM'd you about that!! I was in a rush to get it done though because I wanted to have it tuned to bring it to the track before the season is over, so it was kind of spur of the moment. Of course now I screwed up the front bumper so it looks like shit and I need to get that fixed before I do anything else. Always something.

**9t8z28** · 10-15-2007, 03:52 PM

Originally Posted by Wesman

Oh yea man I should have PM'd you about that!! I was in a rush to get it done though because I wanted to have it tuned to bring it to the track before the season is over, so it was kind of spur of the moment. Of course now I screwed up the front bumper so it looks like shit and I need to get that fixed before I do anything else. Always something.

How did you do in the 1/4?

**Wesman** · 10-15-2007, 05:31 PM

Originally Posted by 9t8z28

How did you do in the 1/4?

Didn't go because my damn bumper is all ruined now!! It really sucks, I'm going to see if I can get it fixed before the season is over so I can go on street legals night and make a few passes.

**richard head** · 10-30-2007, 06:27 PM

Originally Posted by Wesman

Well I had my car tuned by Harris Speed Works in Warminster, PA a couple weeks ago. They did a great job - car put down 341WHP, and it drove great afterwards, up until now.

It was well over 80 degrees when I had the car tuned. The tempurature dropped down to between 50 and 60 degrees for the first time today, and all of a sudden the car feels like a dog. Its got none of the get up and go that it had before, and it feels like like I lost a bunch of power/torque.

For example: Before, I could shift at 2,500 to 3,000RPM at part throttle and the thing would pull great, grab the next gear, same thing - the power delivery was so smooth. Now, I do the same thing today, it barely pulls at half throttle at the same RPM's, and then if I put the clutch in to grab the next gear, the rev's jump way up, like its loading up on fuel.

Any ideas from you tuner pros of what couse be causing this?? Do you think disconnecting the battery (for 15 mins or whatever) would reset the computer for the colder weather??

Try cleaning your MAF. K&N filters get them oily and keep them from working properly - resulting in stuff like you're reporting now.