89 S-10 Blazer, TBI 4.3, 700R4
Timing set as per man, at 4DBTDC. After setting, computer advances to 10ish
DBTDC and shows knock sensor trigerring. The is an auditory knocking sound
that goes away when in neutral or with transmission in gear but TC in
Did some snooping-- found some movement in left side motor mount <installed
new les than 20K miles ago>. used my prybar to put an upward load on the
part of the shell attached to the motor-- audible knocking went away.
In short-- problem is a bad motor mount allowing the steel shell of the
mount to knock against each other, fooling the knock sensor.
Ideas? Replace motor mount with poly parts, perhaps? I've also seen a solid
steel motor mount for SBC that'll fit the 4.3.
No telling how long this has been going on-- I think it's a bit ridiculous
for a mount to go south within 20 big clicks....
Got to snooping this evenng and think I have it figured out.