RE:Lack of Boost, '88 5ktq

[Russ Southerlin <russell.s.southerlin@lmco.com>]

Graydon wrote:

>If you really think it is the fault of the exhaust system, then 
>you could remove the cat and go for a test drive.   It will be very loud 
>as all of your exhaust will be exiting from the downpipe, but it will
>eliminate the possibility of exhaust restriction.

You could also do a visual inspection on the Cat.  You should be able to
see if it is plugged up.

Have you checked your fault codes?

Sound like you simply have a tired wastegate spring if all other engine
functions are O.K.

I had a same thing when I first got my car a year ago.  It turned out to
be nothing more than a tired (stock) wastegate spring.  I went the the
local Ace Hardware and found a heavy duty spring that fit inside the
diameter of the stock spring and then cut it to length by trial and
error was able to get consistently 1.4 bar of boost.  Keep in mind that
this procedure is risky in that if the spring is too long (i.e. stiff)
you will hit the fuel cutoff at 1.5 bar and the engine will shut off
momentarily until the boost drops below 1.5.  I still have the spring
dimensions if you are interested (this would get you in the ball park). 
I did this instead of spending $50 on a new spring.  I also eventually
did a S-Knob mod and still have that extra spring in the wastegate -
haven't had a reason to remove it.

Russ
87 5KCSTQ
Littleton, CO