[V8] Stalling problem

[Shawn Head]

Alright guys, I am really getting aggravated with this one.

 

As some of you know, for the past 6 months or so, my car has been having a
high idle/stalling problem.  The only fault codes that are thrown are:
Lambda (oxygen) sensor intermittent 8:10.  

 

The measuring blocks show that the load is low around 23 when it is supposed
to be around 33.  The O2 sensor reading gets erratic sometimes peaking out
at 166.

 

I have replaced the oxygen sensor twice, replaced injector seals, cleaned
both the ISV and Trottle Body, and Switched out the ISV and MAF sensor from
Dad's 90 hanger queen to no avail.

 

Here are the symptom.  Upon starting the car the idle stays around 900 until
the car warms up and the oil pressure comes down to normal.  However, when I
stop at a light when the engine is cold or warm the car will sometimes
stall.   The engine RPM's will either drop to 100RPM and Jump up to 1200 RPM
in order to recover, or the car will simply stall.  This is even more of a
problem when I am reversing.  Particularly while parking/backing out of
parking spots.

 

I am convinced that this isn't a mechanical problem but an electrical
problem.  It is as though there is a signal that is missing, or that hiccups
for a second and makes the car stall at the light.  

 

What are my possibilities and solutions?  Short of replacing everything!

 

Thanks guys!

 

 

Shawn Head

'91 V8 Pearl/Nautica