Commanded lambda doesn't match the fuel base table

[[email protected]]

This is a 2006 Mustang GT with Ford hot rod cams, JLT 110 mm CAI, long tube headers, and cat deletes. Fuel base table is commanding .84 lambda at WOT. During dyno run up to about 5300 rpm, .84 is datalogged as actual commanded lambda. Just what I expected. Above 5300 rpm, the afr goes very rich and the actual commanded lambda drops to .7. This is actual commanded lambda, not measured lambda from the wideband.
Where did that come from?? I cannot find any table other than transient fuel gain table that modifies fuel. How can I determine what is modifying the commanded afr in the fuel base table? Thanks in advance.

[decipha]

transient fuel does not affect commanded fuel

log fuel source

[[email protected]]

Thanks for responding. Please forgive my ignorance, but how do I log the fuel source? Is this a way to determine what table in the tune is producing the commanded lambda?

[mstang_man]

Unless it is a software glitch, I would double check the Base fuel table setup, then look at your tip in rate change under DBW settings, check you air charge multiplier max is set 1.9, aircharge WOT multiplier is set 1.9.

[momotunes]

If I remember correctly there is a table for the lowest afr allowed for overtemp protection and it's set to either .65 or .7 on stangs. I'm not sure if HPT has that table defined. You didn't post a tune so I'm taking a guess here but disable overtemp protection for 02 sensors, exhaust temp, and cat temp and see if that fixes the issue.

[SultanHassanMasTuning]

post your tune and data log if you need any support

[[email protected]]

If I remember correctly there is a table for the lowest afr allowed for overtemp protection and it's set to either .65 or .7 on stangs. I'm not sure if HPT has that table defined. You didn't post a tune so I'm taking a guess here but disable overtemp protection for 02 sensors, exhaust temp, and cat temp and see if that fixes the issue.

Very good. I will try that. Thanks.

[aaronson]

Im going to agree and say its a manifold or cat overtemp protection. Turn both of those off in the tune. Should be under Fuel tab. then see what its doing. if that doesnt work turn them back on and look somewhere else.

[[email protected]]

I appreciate the rapid response. I already had COT disabled. I increased the threshold temp on both the flange and O2 overtemp protection to 2047 degrees. I did a couple of WOT runs on the highway and the commanded lambda matched the base fuel table. It appears to have fixed the problem. I will do more dyno tuning in 3 weeks so will know for sure then. Is there any resource that explains all the parameters of a Mustang ECU and how they interact?

[momotunes]

Nothing really for the 3V's that I could ever find. Lots of info for Coyotes and 04 and older which a lot of what you learn from those can be adopted to 3v's. decipha website is a really good place to start. Hats off to him for taking the time to put everything online.

On another note, I'm not sure if HPT has increased support on the 3v's but when I looked last they were missing quite a bit. There is a lot to get the job done but you may have to go about it a different way depending on your OS/modification combo. At least in my experience. When it comes to the torque model there are a couple of different ways to do it and each will give the same end result.