98Zheadsncam

iTrader: (26)

The only change is a Fast 78 in place of an ls6. Can anyone tell me which parameters should be changed for the tune to be correct with the FAST as opposed to the ls6?

Thanks.

HCI2000SS

iTrader: (2)

Yuo'll be doing the tuning yourself then?

98Zheadsncam

iTrader: (26)

I know nothing about tuning...I'm borrowing efi live from a buddy. This is my older tune. I've since gotten a second tune with the fast intake, however, drive-ability isn't as good as with this older tune. I wanted to see if I could just use the old one with some minor adjustments. Not that easy?

therealcreeper

iTrader: (37)

do you have a wideband?

98Zheadsncam

iTrader: (26)

I do.

JDMC5

iTrader: (3)

on paper you should only need to tune the VE table. However, you might have to tweak some idle tables if stability issues arise.

98Zheadsncam

iTrader: (26)

Yea, the car has a surging idle. Even with the other tune I have, which is for the heads/cam/FAST, which I'll post in a few days, the car has a surging idle, but only in open loop....Again, I want to use the tune I posted because it just seemed like the tuner spent more time on it..

JDMC5

iTrader: (3)

if it only happens in open loop I would look at fueling. Can you post a scan?

98Zheadsncam

iTrader: (26)

Sure, my buddy is sending me efi live from out of state, so when I get it (hopefully sometime this week), I'll post a scan.

Undertow74

iTrader: (45)

from a ls6 to a fast 78 you shouldn't be having too many issues, or course a tune will dial it in. you say it is surging are you sure you do not have a vacuum leak around the intake, or maybe you have to do a TPS relearn?

98Zheadsncam

iTrader: (26)

It's funny you mention a vacuum leak. I bought the FAST brand new...yea, a 78, brand new, less than two years ago. It was new old stock. I've pulled the intake several times, because I was thinking the same thing..maybe there was a vacuum leak. However, if there is a vacuum leak, wouldn't the idle surge in closed loop as well? I wouldn't think it would be limited to open loop only. The tps relearn i've done countless times..I don't think that's the problem.

The other thing that comes to mind is maybe I should replace that rope gasket that goes in between the runners. It seemed pretty smashed when I last pulled the intake apart.

JDMC5

iTrader: (3)

not necessarily, a vacuum leak can cause the car to run lean causing a surge, in closed loop the computer can correct. I would check idle air trims, if they are way minus, there's your problem.

I would also check ltft's, we're just shooting in the dark without that info.