Scanner book Dirty TPS cause stalling problems

Dears,

I have purchased ScannerDanner book "Engine Diagnostics". It is a very good book. I am at Section 20 Page 12. I cant clearly understand why dirty TPS cause stalling.

Any video or easy clarification are appreciated.


Thank you

Hey karim. The TPS % here shows the difference between a dirty throttle body and a cleaned one. Actually the next page does As you can see in example 2 (page12) we have a 10-25% window of operation for idle load compensation. With a dirty throttle plate we'll need to compensate more and more (the dirt is an obstruction for airflow so we need to open the throttle more) but since we're limited to 25% of opening (pcm control) and dirt keeps building up there's the possibility of stalling (opening gap of throttle is not suffucient enough)
See page 12 and 13 same chapter. Notice the TPS % difference.

Moving this to ScannerDanner book & video questions

Definitely check out the classroom lecture videos of chapter 20 on SD Premium.

www.scannerdanner.com/scannerdanner-prem...-speed-controls.html

karim wrote: I cant clearly understand why dirty TPS cause stalling.

Not the TPS (thottle position sensor). The throttle body/plate.

The red arrow points to the tiny space idle air enters. When carbon builds up. This space gets blocked. Idle Air Control can compensate for this to an extent by opening the throttle a little more. When the carbon builds up too much, computer can no longer compensate, you can have stalling problems.

mike-thomson.com/blog/wp-content/uploads...ty-throttle-body.jpg