[Shotimes] What causes power loss?

[George Fourchy]

On Sat, 16 Aug 2003 07:36:01 -0400, Steve Tatro wrote:

>I'd guess your 30k mile timing belt is fine.  It may have stretched a teeny
>bit, but shouldn't be causing any power loss so soon.

Anything can happen to anything, but I ran my original timing belt to 135K, and only
changed it because everyone was screaming at me to change it.  I still have it, and
it looks as good as the new ones on the teeth side...you can't read the writing
anymore on the top side.  It all depends on how the engine is driven.

Check the BP sensor....it's in the center of the firewall, with a single electrical
plug and an air vent in the top.  Your mixture might be off because the car/computer
thinks you are at high altitude.  Swap it with one off a good car and see what
happens.  Also check the cams for alignment with the crankshaft.  Remove the top
third of the plastic timing cover and rotate the engine until the timing marks on
the two cam sprockets are both at the top.  Then look at the damper, and make sure
its timing mark is at zero degrees, more or less, on the timing mark on the lower
third of the timing cover.  If it is advanced more than a degree or two, your cams
are retarded, either because the belt was put on wrong, or more likely, there is
slop at the crank timing sprocket.  Check for slop by rotating the engine back and
forth with your wrench.  If the cams stay still, even for a little bit, there is
wear at the crank.  This usually is a result of what we call "crankshaft cancer",
when someone didn't torque the damper bolt correctly, after a 60K service.  Normally
there is a hammering sound that comes from the sprocket bouncing around on the
shaft, eating away at the woodruff key, but there's always the odd situation where
the noise might not be there.  This crank/sprocket area is one of the few weak
points in the SHO engine.

Just something to check.

George