2001WS6Vert

When the guy dyno tuned my car a long time ago he said he added fuel to attack detonation in the 3500-5000 RPM range. It will dip under 10 A/F ratio and pour out black smoke in this RPM range. I have tried to pull fuel with the PE vs RPM table but it doesn't seem to respond to this. What other tables should I try to lean out my upper mid-range?

Chalky

iTrader: (2)

Is car in OL or CL?.

Can you compare your tune to a stock tune and look for differences?

2001WS6Vert

I'm going to assume open loop because it happens during WOT. I don't have my stock tune anymore, I could maybe try to hunt one down, I'd just like to hear from someone what could affect the A/F besides PE vs RPM at WOT.

Chalky

iTrader: (2)

You missed my point. If car is is tuned and in OLSD, another table is used for AFR.

I suggest you ask your tuner.

2001WS6Vert

It is not speed density, it uses the MAF. I'm hoping someone here can help. I'm wondering if the VE table plays in at WOT and maybe I need to try adjusting that.

jimmyblue

iTrader: (11)

Cat overtemp protection is a fat adder and a possibility here.
If you overlay some bad positive fuel trims you can get very
rich in total.

If the EQ vs MAP vs ECT table is fatter than PR vs RPM then
you will get that instead, even without COT activating.

If you have somehow lost your kittens then COT has no
use and should be turned off.

Tripintaz

If your car is in CLOSE LOOP operation mode it will refer to the PE tables for WOT fueling.

However if your LTFT's are possitive it will add that much more fuel ontop of the PE table.

Also like Jimmy said, COT will REALLY fatten up the A/F ratio if left active on a car without Cats.

But to narrow it down you should find out if your tuner tuend your car for OL only operation, or left the CL operation intact.

Country Boy

iTrader: (24)

The MAF takes over 100% after 4000rpms. Have you modified the MAF recently or has it been recal'ed?

2001WS6Vert

I looked at the dyno graph again and found that the fat spot is actually 4500-5500 rpm (sorry). It haven't messed with the tune in awhile so I'm a little rusty. Since going up a few cubes (418 to 429) and a bigger blower (T to YSi) I am having to deal with some issues. I am maxing the MAF at appr. 4500 so I think the car then relies on the VE table. I did lower that table down in the 4500-5500 range. I now either need to go to the dyno or get into the wideband software to see where I'm at. The car also cuts out from 5500 up and I'm thinking I might need to add more fuel because of the xtra air from the bigger blower. It seems to happen above 10 lbs.. I will try adding more fuel to it tomorrow. I'd just like to get close before going to the dyno. Also I'm pretty sure the ECM goes into open loop at WOT.

Frost

iTrader: (45)

So you are going WOT with a big inch motor and blower with a tune for something else entirely and don't even have anyway of knowing if it's safe?

P Mack

iTrader: (6)

Your car isn't in closed loop at WOT. It will take the richer of the OL F/A table and the PE table.

Whoops, looks like Jimmyblue already said that.

Tripintaz

I know, I meant if he was using a closed loop tune vs an open loop tune.

I do not believe the PE table is referenced when the car is set to never enter closed loop operation mode. Atleast thats how my LT1 PCM worked, the LS1 pcm may not behave the same.

Viper

iTrader: (6)

" I do not believe the PE table is referenced when the car is set to never enter closed loop operation mode."

Yes , it references the PE table whether it is in open loop or closed loop on the LS1 PCM.