LX9 reluctor demystified

[bszopi]

So I was doing some research for another member, and came across something very interesting... http://60degreev6.com/forum/showthre...3400-%28la1%29

3400s built for Chevy Venture, Pontiac Montana and Oldsmobile Silhouette also have a new crankshaft reluctor or timing ring. In other 3400s the timing ring is machined into the middle of the crankshaft. Those built at Ramos, Arizpe, Mexico plant have a new assembled ring. This two-piece, fine-blank ring is heat-shrunk o*n the crankshaft and encoded with a 24X tooth pattern. This timing ring provides the basis for future 3400 developments.

I'll need to see if I can dig up any information, but perhaps the 3500 is a 24x trigger (as Jon has determined), and the 56x is unique to the 3400s in the Equinox/Torrent, as I know they have a different crank trigger. But, I don't ever remember us discussing the new crank trigger back when it was released in 2003.

[Jonpro03]

It's like a daytime drama. I can't wait to see what happens next

[bszopi]

Well, here is the info for the 2005 3400 which was designed specifically for the Equinox: http://archives.media.gm.com/divisio...2005%20LNJ.doc

The 24-X encoded crankshaft helps the engine’s powertrain control module (PCM) deliver accurate spark timing and fuel delivery. The accurate sensor enables the PCM to know the exact position of the crankshaft within just a few degrees of crank rotation. This helps the PCM adjust and deliver the optimum fuel and spark curves for the engine's immediate requirements. This Quick Sync ignition system is identical to that on the 3500 V-6.

And then, in 2007, the Equinox 3400 stepped up to a 58x crank trigger and 4x cam trigger : http://archives.media.gm.com/us/powe...New/07_LNJ.doc

The 3.4L V6 has an advanced 58X crankshaft position encoder to ensure that ignition timing is accurate throughout its operating range. The new 58X crankshaft ring and sensor provide more immediate, accurate information on the crankshaft’s position during rotation. This allows the E38 ECM to adjust ignition timing with greater precision, which optimizes performance and economy. Engine starting is also more consistent in all operating conditions.

In conjunction with 58X crank timing, the 3.4L V6 applies the latest digital cam-timing technology. The cam sensor reads a new 4X sensor target on the cam sprocket. The target ring has four equally spaced segments that communicate the camshaft’s position more quickly and accurately than previous systems with a single segment. The dual 58X/4X measurement ensures extremely accurate spark and fuel-delivery timing for the life of the engine. Moreover, it provides an effective back-up system in the event one sensor fails

By this time, the LX9 was no longer in production, therefore it never received the newer trigger. Interesting...

[Jonpro03]

The 58x/4x is the same setup used in LS2 V8s. There's a 3900 in a local yard that (I believe) uses the 58x/4x and it's cheap! I would love to get my hands on it and add V6 58x/4x support to the Megasquirt. It's just a 60-2 reluctor. Its 3* high and 3* low all the way around the wheel, but 2 teeth are missing.

Lots of pictures of the 24x and the 58x sensors here. http://www.ls2.com/forums/showthread.php?t=653270

On another subject, I think it would be worth it to build a simple wheel decoder. Input a 24x or a 58x signal and have it output a 7x signal for use with GMDIS.

[pocket-rocket]

On another subject, I think it would be worth it to build a simple wheel decoder. Input a 24x or a 58x signal and have it output a 7x signal for use with GMDIS.

I've kinda been wondering why that hasn't been done yet. Especially with some of the electronic gurus on this board.

[Jonpro03]

I'm going to school for electronics, but I'm not far enough along to be able to build a circuit that can do that. Not to mention that it will likely require some C programming, which I self-admittedly suck at.