Thread: Boost reading
View Single Post
mark houghton mark houghton is offline
Registered User
mark houghton's Avatar
Join Date: Jul 2008
Location: Central Washington State
Posts: 3,776
Originally Posted by BSKI View Post
Any way of testing the overboost sensor?
The only real way to test the OB sensor switch is to take it off the car, hook a hose up to the threaded end, and apply controlled air pressure to it. With a VOM (ohm meter) hooked up to the spade and body, slowly increase the air pressure until you get an open circuit. Somewhere between 1.2 to 1.4 bar.

That switch working is only half of the equation, though, as Jim has pointed out. The switch in turn interacts with the yellow overboost relay to shut the pumps off. If the relay is faulty, then of course the whole protection system is null and void. But the good news is that if the relay is malfunctioning you'll generally know in the car won't run, boost or no boost.

Were you running the stock 3LDZ turbo before ungrading to the 7200? As already pointed out, you will build more boost and - even more importantly - much sooner than the stock turbo. Thus, you may see momentary spikes beyond your WG spring setting, but generally you shouldn't see sustained or increasing boost at that higher level once the WG has opened.
Mark H. 1987 930, GP White, Wevo shifter, Borla exhaust, stock everything else. The result of a massive Pelicanite good will fire recovery effort. Truely an open book, ready for the slippery slopes to modification.
Old 03-14-2010, 08:34 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)