FAST issue

[RegalX2]

Need some help, trying to get a used classic seq. FAST figured out. Drove to track w/ FAST installed, ran well on street, had decent A_F #'s all around. At track, had a fellow FAST user tuning the program I was provided with. At first all went well, setting the VE cells per O2 corrections while running low boost. But after a pass, the VE tables would be different causing no idle, lean backfire on startup, etc. We reinstalled a couple tuneup programs, re- installed C com, Last time at track, more trouble, way rich idle, showed 10 :1 A-F #'s had to set idle VE #'s in the teens just to achieve idle. Reinstalled OEM ECM for the rest of that day. This is an older FP box with new O2, with V1.02 software and a FAST USB adaptor, newer Acer PC w/ XP

Thanks for any help
Jim

 

[norbs]

This ran ok with the stock ecu after? no other changes? Sounds very strange for it to go rich for no reason, unless you have other mechanical issues, bad injector, etc in the motor

 

[Otto J]

Did you install the option file with the new 02?

You cant just throw a new o2 at a classic system without
install the option file for hte new o2 or for the universal o2

 

[Chuck Leeper]

Sounds like this is the problem??
"But after a pass, the VE tables would be different causing no idle". When you made the changes, did you save the new tune as a new file name?
Been a while, but didn't the older FAST have a problem w/ retention of the tune??

 

[RegalX2]

Not sure about the option file being installed. I bought it used W/ new o2 included, was told I would know when I started it up. How do I tell if its installed ?. I do remember the UEGO #'s were 2.8, not 4.0 like the FAST help states.
We renamed the new files, car ran OK, then when picking up timeslip it went way lean. The idle VE #'s were about 10 lower than they were before the run.Then I went back to track the next week, hooked up FAST,and then had rich running with low idle VE#'s, ( like 15-19 ). I tried a known good tuneup file downloaded from another FAST user w/ same basic setup (83's,) it wouldnt idle it was so rich.
Yes, the car ran well on the OE stuff.

Thanks