Does anyone know the frequencys the tpi,tbi and lt1 iac's use
I have allways thought the tpi/tbi and lt1 iac to be bi-polar, but Im helping a guy working with a Edelbrock Pro flow system using a ls iac and it will now move the iac
Using a 165 ecm. Edelbrock tech support says the ls iac is pwm at 15.26Hz and the don't know what the tpi one is. I'm thinking a simple solution is make a external iac
Bye using the stock tpi lower iac plate and a block of aluminum and use npt barb for the vacuum and use a k@n breather on the other passage. I just wanted to see what information there is regarding the tpi iac


http://www.megamanual.com/ms2/IAC.htm

 

160 steps/second is the fastest the ECM will move the IAC.

They are a bi-polar stepper motor, which can be held in position or stepped as slowly as the ECM wants.

RBob.

 

Is the LS iac any different in function ? I would think it should work with a 165 ecm. I was thinking the edelbrock guy didnt know what he was talking about.

 

The LS IAC's are also bi-polar steppers. Not sure of the maximum stepping rate.

RBob.

 

Thank you as allways Rbob

 

RBob,

While on the topic of IACs, what exactly does a MAT v Decreased IAC steps table do? I ask because the table values are pretty high and it doesn't make sense that the ECM would reduce IAC counts by that amount.