MS3 base idle/decel surge

[masterofmachines]

I have just completed installation of my MS3 v3.0 (1.5.1 firmware) and have the engine of my 280zx turbo starting & running ok. Throttle response is generally good & engine seems to run great under load. Even idling in drive is enough load for afr's to read normal & tach to be stable. However, when idling in park or neutral after a few seconds the rpms start to fluctuate, and as this is happening the afr will begin to swing wildly from about 10-1 to over 17-1. The frequency of the surge is prob about 1 per second, and it progressively gets worse until the engine stalls. The surging persisted even if I crack the throttle and raise rpms. It smooths out, however, if the trans is shifted into drive.

[elutionsdesign]

Flatten out the VE table in the idle area, you can see in the log the VE cycling up and down about 50%.

[DaveEFI]

Start with all the VE table boxes around idle with the same numeric value, and group them. Change them all together for the best idle. You can then trim individual ones if needed. Drive always seems to need a slightly richer mixture than neutral.

[okubricko]

Do you have an idle valve connected? I got surging under idle with my install with my idle valve initially. It was recommended in the manual that you get you VE tuned before adding the variable of the idle valve into the equation (if you have one). Also, you can turn off including the AFR table in the fuel corrections as well at first until you get a stable tune.