Got the car dyno tuned and on the way home I found some things I don't like and would like to adjust. I'm going to call my tuner but I'd like to know what issues might be so I can better describe to him...he is 4 hours from home and right now I am 3 hours from there.

In gear the car idles perfect until rolling then rpm climb with no throttle even high enough to shift to 2nd...very hard on brakes.

On the highway when I let off from a locked highway speed cruise the engine rpm hangs, then drops hard...during the drop timing goes from 40* to 2*, after a second rpms shoot back up (timing follows) then falls slow and the engine feels like its engine braking a ton harder than it does with the old tune.

These should be easy fixes I think...I have efi live and my tuner has hp tuners otherwise I'm sure it would be even smpler as we could just email tunes.

 

The idling problem is Throttle Cracker. It needs to be lowered or disabled somewhat.

The other problem sounds like maybe DFCO is too aggressive. Try disabling the DFCO and see if the problem goes away. If it doesn't or if your DFCO is already disable then it'll be one thing to check off of the list.

 

I agree with above; sounds like the Throttle Cracker. Try to disable it completely.

Could be a few things; Throttle Follower, DFCO and possibly the spark tables. If you have the old tune; use the comparison feature in EFILive to view the differences between the old and new tune so you can pinpoint the changes.

 

DFCO are the same in both tunes

The throttle follower values are not, what should I be looking for as far as values that would cause this change?

I haven't looked through all the timing tables yet but I haven't seen one that commands such a low advance like that.

These are 2 entirely different tunes, first was a mail order tune tweaked and the new one was a dyno tune that started from scratch (hence me losing all my transmission settings I had tailored to my own driving style)

 

The idle overspeed spark control can cause it to drop off quickly during closed throttle conditions. I always zero out the last cell in the table just to avoid that.

I doubt it's setup to see that kind of drop that you are experiencing though.

Have you tried posting the tune and a log on here or EFIlive forums?

 

Not yet, I got home late after the tune so I didn't have time to go run logs. I'm in the process of moving but hope to be picking the car up and taking it to the track this weekend.