MoTeC Global Forum

i recently encountered with boost leaks with a car i tuned.
the map sensor reading were stable, but, a faulty idle speed valve was sending the boost through.
that car was poorly built and didint recycle it's ISV into it's intercooler piping.
the map sensor read about 3 psi of boost, also the other mechanical gauges attached to the vaccum hose junction
read the same. i have replaced that valve and got a new boost reading so i understand it's malfunction.

the thing is, how can it be detected, without pressure testing the boost pipes?

That sort of leak would be fairly difficult to detect electronically while running.
The only way i could think to do it is to use an air mass sensor and map your MAP, Eng RPM, Air temp etc. to do a comparison. A small leak probably still wouldn't show up...

Sounds like the ISCV was causing a massive leak if you wqere only seeing 3psi. Surely this would have been clearly audible ?

the car actualy run about 5-6 psi, and no, it wasnt audiable, the car has open exhaust piping and it
could not be detected by ear.