Re: Bogging down/hesitation

[Chris Newbold <cnewbold@transarc.com>]

Jim Griffin wrote:
> 
> My '92 100S, with V-6, has recently been bogging down (like a bad case
>
>...
> 
> At 121,000 miles, I have never had my OXY sensors replaced. Should
> they be replaced by this time? Any other possibilities?

I'd definately check into the O2 sensors. I'm not convinced that they
could cause such severe symptoms without lighting the "Check Engine"
light,
but from past experience they do tend to let go rather suddenly.

The "Check Engine" light in my '93 90 (also with the V6) started coming
on around 45k and the computer fingered the O2 sensors. Replaced under
the 50k/5yr emissions coverage (thankfully!).

I can't say that I saw much change in engine performance from before the
"Check Engine" light, to the week or so it was on before getting it
fixed
to after having two new sensors installed...

Lack of power over 4000RPM could also be caused by problems with the
variable intake manifold. The butterflies are supposed to open somewhere
around 4000RPM. I can really feel the surge under full throttle when
they
open, so I can imagine it would be pretty gutless if they didn't...

At your milage, I can think of a whole bunch of other stuff that you
should consider. None of it should have resulted in such a sudden
onset like you describe, but... All of these are due every 30k or 60k:

	- spark plugs
	- fuel filter
	- air filter

Just did these myself as I hit 60k. Always make a tremendous difference
to drivability, smoothness and power over 4800 RPM...

Another thing to check is the adjustment of the throttle cable. I've
noticed
that it seems to stretch a lot. When I first noticed it and readjusted,
there was a teriffic difference: added 10MPH to my speed at the end of
the back straight at the Glen. The cable must have been so lax before
that
I wasn't hitting the WOT switch...

-Chris
1993 90CS, 60k