RE: 87' 5KQT turbo overpressure

["Lewis, Gary M" <Gary.Lewis@West.Boeing.com>]

Matthew said;

> My newly-aquired 1987 5KQT is consistantly activating the turbo
> overpressure switch (fuel cutoff) when accelerating under part or full
> throttle conditions.  It accelerates very nicely up until it hits the
> overpressure switch and it is possible to accelerate without causing it
> to trigger but I must be careful.  At an indicated 1.5 bar pressure
> reading from the dash guage it appears to trigger which sounds normal.
> I can't seem to locate and vac/pressure leaks but it has been cold
> outside and I may not have been as thorough as I should be.  Any clues
> as to where to check first?
> 
Take off the wastegate cap.  There is a beige/light brown gasket you need to
inspect.  If this gasket (called a wastegate diaphragm) has a small whole or
tear, that will create your problem.  It seems to tear at the place where
the diaphragm bends, kinda in the middle.

Another place is the lower wastegate vacuum hose.  If this thing has a
vacuum leak, same results.  I'd bet it is the diaphragm.  I've replaced 2
lately...
HTH,

Gary Lewis 
88 5kcstq 1.8 bar 110km Pearl w/Fuchs, K24 turbo, 2-piece EM
86 5kcstqw Sapphire and Platinum, stock 
TransGlobal Financial  (818) 384-7600
Mergers, Acquisitions, Public Offerings


> My sincerest thanks,
> 
> Matt Poynter
>