Hi Guys,

im wanting your opinion on the following.

I have a 03 VQ35+T (HKS SINGLE KIT)
has ID 1000cc injectors
Aeromotive FP

It was leaning out on each bank -+ off cruise so my tuner changed it to running a closed loop and now it running super rich. big puff of blue smoke when you take off, and car stinks of unburnt fuel on high boost 9psi.

I want to know;
in running a closed loop what do you lose from a tuning point of view.

love to get some sort of discussion.....

 

your fuel table is way off then. closed loop just allows the ECU to use the target AFR table and adjust the fueling amounts from the base fuel table to hit those targets. By turning it from open to closed loop should not have changed the AFR much at all if the tune was done correctly.

I target less than 5% compensation between my open and closed loops. The stock ecu can target up to 20%, so that means your tune must be more than 20% off.

The benefit to a closed loop is that is compensates for environmental changes (temp, altitude, etc). You lose nothing over open loop, unless your compensation tables are way outta whack, or you are moving too fast thru the fuel table to allow the ECU to make appropriate changes