cliffyk

I have had a number of discussions over the years regarding the TPS on our cars and have found a lot of misunderstanding and misinformation as to what it does, and does not do.

Here's a link to a document on my site providing some information about how it works and what the PCM does with its output signal.

I am working on a similar document for the IAC...

WannaBeGearHead

Good little read. I'm not sure what people thought the TPS does but it looks like that would clear things up if they had questions.

cliffyk

The most prevalent bit of misinformation, one I have even heard from professional tuners, is that it adjustable and needs to be "set" to some particular value when closed; with 0.6V, 0.8V and 1.0V being commonly put forth numbers.

I've read posts where people have complained vehemently because the aftermarket TPS they bought from a FLAPS did not have "slots" and could not be adjusted--with responses ranging from "You should always buy Ford parts!" to "perhaps you could file slots or use a Dremel tool?"

stevednmc

Well...if the one you pulled off doesnt have slots, then the replacement shouldnt either...if ford wanted it there they would have put em there...im guessing...

WannaBeGearHead

In Greg Banish's Engine Management book he does say "we usually read output in a 0 to 5-volt scale with 0.5 to 1.0 v usually indicating closed throttle..."

My understanding after reading that part in the book was that 0.5 to 1.0 v is usually the output range for closed throttle. So if they say the value needs to be a certain V then I understand how that is wrong. My understanding is that the tuner needs to figure out the difference between closed throttle and part throttle. Closed throttle most likely being that 0.5 to 1.0 v range.