I have searched this and I didn't find the right post or answer I was looking for. I know that 128 is best for your air/fuel ratio. I need to know if that number drops to 112-116 while at cruising speeds, is that too rich or too lean? I have a scan tool in my car at all times so I can watch this. Will that condition at cruising speeds have any affect on the air/fuel ratio at WOT? The readings for BLM at WOT is ALWAYS 136. It never changes. I guess I am curious.
Thanks in advance,
Jim

 

The BLM at 112-116 means the engine is running rich and the computer is leaning down the fuel to compensate. This low reading has no affect at WOT. At WOT, PE kicks in and riches the fuel mixture. Hope this helps!

 

Ok, here's the story. I am modding a 3.4L V6 using the ecm from an 1989 2.8L V6. I have upgraded from the stock 14# injectors to 18# injectors. I will assume that I will need to adjust the power enrichment to compensate. I mean if I am running too rich under cruising conditions, couldn't I assume that I would be running too rich at WOT too?

 

Yes, it will be richer at WOT too. Best bet is to tweak the injector flow rate term until the BLMs are centered about 128 across the board.

Then, for perfection, and if required, tweak the MAF scalar tables.

RBob.

 

Yes, I know I have to do the MAF tables also. I convert the Throttle Body and intake from the original 48 mm TB to a dual 48 mm TB and intake from a TPI setup.