Engine roar is weaker after 3 months of no battery
 

Hello,

I recently had my 97 Boxster painted. It took 3 months to finish and the battery was removed during the time. I just got the car today. Aside from my top having problems (had already posted it in a separate topic), I noticed that my engine is somewhat slower after. Previously, before the paint job, I remember my engine sound and roar very loudly specially on the high RPMs. But now the sound is kind of weaker, quieter & tamed. Does this have something to do with the computer forcefully ressetting or something? Is it because of the 3 month inactivity with no battery? The performance on torque and revving and speed build up is somewhat affected as well by something like 20-30%. (just my approximate based on my feel of the car)

Though idling and starting had no problems. 1 click start.

Anyone got insights on this? Do I need to bring it to the dealer to have the computer reset or to have it reprogrammed or sport-tuned?

Any input is welcome guys.

Thank you in advance!

Make sure you have fresh gas in the tank and go for a spirited drive. The on-board DME is currently in reset mode and it will re-learn precise performance settings in a few days.

What Topless said. It'll probably get itself back in business after a good 100 miles or so.

So driving it will repair/relearn itself just like that? No more need for another diagnostics reset at the dealer?

Thank you for replying.

The ECU has the ability to "tune" itself as you drive. It will slowly adjust several engine parameters like fuel mix, timing, and how they vary over temperature to provide the best performance and lowest emissions.

These adaptation parameters are stored in the ECU and lost when the battery is disconnected. As Overdrive and Topless have suggested, just give the engine about 100 miles to refine the engine tuning. Spirited driving will help the engine to tune itself more for power than low RPM emissions.

If you're still having an issue after that, post back here and someone will suggest the next logical step.

Somewhere I saw posted the exact number of cycles of warm-up, speed, length of drives, etc that it took for the ECU to completely relearn and be ready with all the little things adjusted to your octane, altitude, etc. But the general approach is just drive it under varying conditions for a couple of days. It the beginning, you are driving with darn little of the computer to help you. Over time....

Did your airbag light come on?,,,,with mine whenever there's a power interruption the airbag Light sets

Okay. I will just use all the gas in the tank and refuel then drive it "sport style" hehe.

But as of now the engine performance seems to be picking up a little and almost already comparable to before, or maybe just less 10%. I may have to drive it more spirited. Though its improving. But the thing that worries me now is the engine "roar" sound or engine growl is not like as before. It sounds more tamed now (very quiet) as compared before.



@jakell2010

No my airbag light did not light up after the 3 month long "no-battery" mode.

3 months in a paint shop ? This may sound dumb. I would check and clean my air filter and intake passage. Those shops can be very gummy/dusty.

Did you go with the original color? Any pics?

Thanks...

I used the X4 color code (speed yellow)

Here are pics.

http://i226.photobucket.com/albums/d...s/IMG_2823.jpg

With custom seats and full carbon fiber interior kit:

http://i226.photobucket.com/albums/d...s/IMG_2831.jpg

Beautiful!
 

Great job, gunman168.

Thanks for posting the pics.

Did you do the re-set of the TBI? Not sure if you have drive-by-wire throttle, on mine you have to turn the key on after connecting the battery, and let it sit for a minute or so, then shut it off. Then you can start it.
Car looks great, nicely done.

Have not reset anything yet.

Thanks guys!