Lean Idle Problem

  • Thread starter Thread starter I1ULuz
  • Start date Start date


I had a computer crash and must have nicked a file, but that is when the trouble started. Yes I know to back up my files to floppy and maybe even CD now.

If I rev the engine, comes back down to idle then slowly to max lean, with a lean backfire sometimes, RPM's drop, then the engine stalls or might even recover. Does it once, if it don't stall it will idle just fine.

It is making driving a pain.

Any ideas where to look to correct this problem?:confused:

With the Accel DFI there is a table called "Throttle Follower", it adjusts the fuel based on the rate of deceleration.

At least thats my understanding.

Maybe there is something like that within FAST.


There is, and that don't help. It will reach the desired RPM and with data logging you can watch it keep going lean. Till it flatlines on max lean with the WB readings. Then it will catch and go back to normal idle.

Hey Chris, sorry to hear about the computer. I had the same problem when I first started mine up. I had to adjust the throttle follower. I then adjusted the minimum air setting on my throttle body to fine tune.
While you are returning to idle you are still under boost right?
I would think your IAC should be low since you are still receiving air from the turbo.(you know I don't know much about turbos)

Are you idleing in closed loop?

I can rev it sitting in the driveway, and it will do it. Will look at the idle A/F ratio for idle.