Posting this for a friend...he has a 94 prelude, turbonetics kit, darton sleeves, rods, pistons, 780cc injectors, hondata s200, ect, ect.

Now, the shop that tuned his car did a really shitty job, didnt do any partial throttles and the idle is total crap. So he took it to another friend of mine to get it looked at and see what he could do.

Friend hooked up a plex a/f to the 02 bung, and the car was running 10:1 at idle, EXTREMELY rich, black smoke out of the ***. So, he hooked up his laptop with the hondata software and tried adjusting the fuel. Took out 1% of fuel, idle was a little better, kept taking out 1% until he got it to about 12:1 (he said he was shooting for 14-14.5:1 at idle). Now, after he got it to about 12:1, when he took out another 1% the motor totally leaned out, plex read LEAN, and the motor died. Tried to start it, wouldnt start because it wasnt getting enough fuel. Added enough fuel to get it to start again (by that time it was again around 10-11:1). Tried taking 1% of fuel away at a time, and the same happened, motor died and totally leaned out before he could even get it to 13:1.

This was tested with both Hondata and Uberdata, so its not the software. Also, when he would get it to 12:1 or there about, the a/f would gradually go down and get richer and richer.

Bad Injectors...Vacuum Leak? What do you guys think? TIA!

 

no one with any insight?

 

bad o2 sensor? partial throttle will only run off the maps if its you force it to, or its is throwing certain codes.

A bad o2 sensor will def **** up A:F across the board if its not working properly.