Hey everyone,

I am running a tbi 350 with a '7747 and trying to pass emissions testing. The motor passes the Driving Test (dynamometer) but fails on the Idle Test. It's running WAY rich and maxes the sniffer out with >2000 HC!!! CO is measured at about 6.5%.

I'm using the AKAL bin which calls for 600-650 RPM idle speed, and has the open loop AFR Enable/Disable pair set to 750/850 RPM. The motor is idling in open loop at about 650 RPM with a few counts of IAC.

Will taking fuel out of the affected VE cells (400/600 RPM, 20/30 Kpa) clean up the idle?

I appreciate any help on this, cuz I am flopping around like a fish out of water!

 

Yep just pull some fuel down there, that should help out. You could also move your open loop enable RPM down a bit to get the O2 sensor in on the act.

 

Thanks a lot for the reply. I will take a run at the VE table and let you know what happens. I'm also looking into getting one of RBob's sweet EBL boxes and a moates wbo2.

The funny thing about closed loop idle is that I ran it thru the test the first time with the idle set at about 1000 RPM (using throttle adjustment screw.) It was idling in closed loop with the IAC closed with 0 counts. The hydrocarbons were still off the chart.