I wouldn't replace the sensor until I'd checked it's output at operating
temp with a volt-ohm meter (VOM). The distributor is "indexed" by
rotating the distributor body to line up the notch on the distributor
switch plate with the rotor when #1 cylinder is at TDC on compression. It
takes a 1/2" crowfoot (on my '92 3.9 anyway) to get to the distributor
clamp bolt. The SBEC adjusts the initial timing on startup with output
from the crankshaft position sensor and probably others. When mine was
doing something similar it was the distributor being "out of phase".
After the dealer replaced the distributor and the mechanic didn't index it
right (can't believe it moved that far out of spec by itself) it went back
and they reindexed it right and it's run great for 10K miles. By the way
all the plugs have to be removed so that the engine can be rotated by hand
(with a socket and ratchet on the vibration damper bolt/nut).
Good luck.
Larry Elliott
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:07:30 EDT