Possible (?) Engine Hesitation Fix.

[wwest]

Both Toyota and Lexus seem to be suggesting that the use of Premium fuels will help to alleviate the transaxle downshift throttle delay sequence. Some posters have indicated that it does seem to help.

With that thought in mind has any one tried one of the various HP "boost" systems(***) that modify the IAT (Intake Air temperature) signal? These systems seem to falsify the IAT signal in a way that results in running a richer mixture than the optimum insofar as lower emissions levels are concerned.

Seemingly the same effect as using a higher octane in that the engine would be less likely to knock or ping.

***:

http://www.hurricane-horsepower.com

or google for:

"progressive tuner"

[SKperformance]

The problem is toyota ECu's are self learning .They take other measuerments to determine is a sensor is not readin right and then compensates it back to an original bandwith.

So by adding a resistor to the MAF the ecu will give you more gas thinking the air is colder which equals power as well.

Problem is it will shortly revert to normal. It is the same problem many have had with the Apex-i controller which is a variable rate maf signal modifier. It soon has its base lines thrown out by the ecu.

[wwest]

That's what I thought at first but for some reason the engine ECU doesn't seem to "learn" that it's being lied too by the IAT signal. Assuming of course that the signal remains within the bounderies designated in the shop manual.

I had always thought that these various "tuner" kits, IAT sensor, engine coolant temperature sensor, etc, only worked at WOT so that there would be no pre-emptive learning opportunity.

But apparently not.