Just to share with others another experience with my 1999 SE, Series II 3800, VIN "K". The symptoms were quite simple: Engine died (just like turning off the key), no warning of any kind, no codes set. On one day, it happened four times, once at very slow speed in town, once on freeway off-ramp, twice on highway at 75mph, all in a two hour time frame. Next day, same trip, never died once. Sometimes it would "re-light" on it'* own, sometimes had to restart. But it always restarted right away.

Problem turned out to be caused by a failing crankshaft position sensor. Apparently it was never in failure mode long enough to set any codes. - -And while I had the crankshaft pulley/harmonic balancer off, I also replaced the camshaft position sensor too. Price for both parts, just under $100.

For those of you who do your own mechanical repairs of this type, here is a REAL GOOD thing to know: The harmonic balancer/crank pulley assembly has three slotted holes. About two inches in from the surface, the balancer is drilled and tapped to accept three 1/4 inch fine-threaded bolts, to use with your three-slot puller. (thank goodness I had the GM Shop Manuals !!) At my local Ace Hardware, I picked up three grade 5 bolts 3 1/2 inches long. They worked perfectly with the standard/generic three-slot harmonic balancer puller. (-you will have to "feel" for the bolt holes, and be careful to have them lined up straight in, to make sure you don't "cross-thread" them.) I also used some penetrating oil, to help loosen up the dirt in the threads. -good idea to run the oiled up bolts in and out a couple of times first, to clean the threaded holes, before actually using the puller. -also, don't screw the bolts in more than about 3/4 inches, to avoid contacting the cam cover/housing.

Only took about 90 minutes total.

Might be something good for an Admin to add to Tech Info...