New custom tune on my computer or not.

[68EFIvert]

There is a local tuner that donated a tune for a member of our local mustang club. The guy that one it has a 67 that he is going to sell and a 03 GT. He doesn't want to do it on the 67 and doesn't want to spen $375 to buy the programmer for the 03. He called me up and offered it to me. My car was originally tuned by this shop when I put in my first engine. They were very expensive becasue they chased down a few problems I was having. The end result was a good tune.

My new engine was tuned by another shop in town. It is very good under full throttle but I am having some issues with driveablility. It wasn't to stall sometimes when I go from hwy cruising and then put in the clutch. The idle drops very low and then starts to surge. I think it is an easy adjsutment by the new shop and they offered to do it for me.

If I take the car to the free shop they will do a new tune for the dyno and driveability. The question I have is should I have the free shop do it knowing they will create a whole new tune or just take it back to the tuner that tuned it and have him touch it up? What are your thoughts? Both options won't cost me a thing other than gas money. :confu

 

[Horseplay]

Seems rather simple to me. Take it to the first shop and let them fix it. If you're happy with the result pass the free tune along to someone else. If not, let the new guy give it a shot as he can't be worse than the first who couldn't get it right either time.

 

[monkeystash]

If I take the car to the free shop they will do a new tune for the dyno and driveability.

This seems like a no-brainer. New tune, another dyno session, and driveability issues addressed.

 

[66gt350]

I'd take it to the shop that did the tune. They know you and they know your car. You're not starting over from square one with a new tune. You might get lucky and no problems, or you might get a new one. There's tons of scalars, functions, and tables in the computer and if one isn't just right you will be banging you head against the wall. If the idle surge is anything like the one I had, it's running way rich then way lean...the computer is trying to compensate and can't. I've changed so many variables, I can't recall which one got rid of the idle surge...it was either the curve on the mass air flow table or the flow across the throttle body. I've still got a long ways to go doing this myself...I'm running extremely lean when it's cold, and a bit rich at times that it will bring tears to your eyes....

Hand off the free tune to another member in your club...it's just good karma.