deceleration enleanment

[LETZRIDE]

Would it hurt the car if I set my disable TPS Delta to 0.25% and my Enable TPS delta to 0.25%?

My gas milage has gone up quite a bit since I installed the cam and did some tuning...this time last year with the same driving I was getting around 330-350k...now I am getting 420k +....so it is a BIG improvement. So I am just trying to tweak a little bit more out of it...I notice that sometimes it doesnt go into decel enleanment when I am in the city and off the gas pedal...The only thing I am kind of worried about if I set it at .25% is it will always go into decel enleanment, and I am not sure if that could cause engine damage since it would happen so often...

right now I have it set at disable TPS Delta -1.5% and Enable TPS delta 1.0%

[ssms5411]

Re: deceleration enleanment

I never mess with decell in hptuners , heard bad things can happen.

[LETZRIDE]

Re: deceleration enleanment

like what?

[ssms5411]

Re: deceleration enleanment

Just like backfires and car doing werid things, shutting off and etc.

[vr4gasm]

Re: deceleration enleanment

i think my tuner messed with mine he is one of the best on this side of the mississippi people drive 15 hours to get to him on a weekly basis.. anywho when i am under deaccel the car acts weird almost like it is spitting and sputtering from 50-40 ish

[LETZRIDE]

Re: deceleration enleanment

hmmm....maybe I'll leave it alone for the time being...

Just trying to think of things I can tune for a bit better milage...without sacrificing power...Like I said, since I cammed I gained alot of milage, so I am not complaining...

[ssms5411]

Re: deceleration enleanment

Its all fun and games until a piston goes through the block.LOL being cammed just make sure you run it a little rich so nothing blows up.

[saltnvinegar6287]

Re: deceleration enleanment

To add to this old post, I just recieved hptuners this week.

Before the 97 computer and hptuners, my plx wideband would tell me I go ~19.0/lean/air when decelerating in gear. With the 97 a4 computer and a stock m5 tune, decelerating in gear would physically not really occur and my plx wideband would read around 14.7 still. Also, between shifts my rpms would float around. Deceleration enleanment was the only cure.

[ssms5411]

Re: deceleration enleanment

A M5 if you have the clutch in, will decell quicker than a A4, a A4 will keep a load on the engine keeping it at 14.7 and then continue to idle at 14.7 since their is aleays a load on the engine , I found this out becuase I had a M5 for 10 years and then swapped a A4 in and noticed the diffference in tunes, you have to have the right file for if it is a M5 or A4if not flash it with the correct tranny . Also noticed how the tunes were setup different like fuel and timing. Messing with decell is risky , I wouldn't recommend anyone using it. Also none of the tunning guides have info on it so, that also gives a good hint not to mess with it.

[LETZRIDE]

Re: deceleration enleanment

my decels to 21 afr?

[ssms5411]

Re: deceleration enleanment

Mine will decell , but when I come up to a stop light it will go back to around 14.7, this is on the auto.

[LETZRIDE]

Re: deceleration enleanment

ya...thats what it should do...

[saltnvinegar6287]

Re: deceleration enleanment

So does mine LETZRIDE.

As ssms5411 said, the m5 and a4 have different fuel and spark curves due to the constant engine load from the torque converter. I did copy ALL tables from an m5 stock tune to the a4 before I began.

Because I logged the changes in list form during this compare operation, I know this included Transmission DTC's, putting all transmission tables to 0 except forced current (don't know why, but thats how it was on two m5 tunes I used), and slight modifications to most of the engine tables.

However, my driveability was horrible until I changed my DE tables so my rpm's would fall as they should. I know every vehicle is different. Mine required some change.