ULTM8Z

I'm about to embark on an LT1 conversion harness for my Miniram'ed SBC. Going to transplant the Opti-guts into my HEI distributor.

Question, is that pickup sensor replaceable? Such that there's a separate part number for it?

I don't want to spend a boat load of money on a new Optispark. Would rather get a malfunctioning one really cheap just to get the mechanical guts out of it and then put a new sensor in it.

Thanks.

jaa1992

Chandler motorsports seems to have a good price on new optis - PLUS a ton of knowledge.
If they don't drop in the thread send them a PM or email.

ULTM8Z

Thanks! Will do.

EDIT: Just called. They don't sell the sensor separately, unfortunately.

84vette96

I looked all over for just the sensor with no luck. Had to buy the whole thing. Hard to believe something held on with two screws is not replaceable.

lt4red

The sensor is optical, not magnetic, and I have seen this done on a thread somewhere. You will need to bring the reluctor wheel with it also. The engine will run with the low res signal only, or since your bringing the whole deal, might as well have it use the high resolution signal as well. I have read the sensor is made by Mitsubishi, but I don't know of a source for one, except an opti. You may have a rough time getting the sensor and wheel to fit inside a normal HEI as well. I'll see if I can find that old thread, may have been on camaroz28.com or ls1tech.

Link to a guy who has done this.

http://www.ls1tech.com/forums/lt1-lt...easer-pic.html

ULTM8Z

What is the high resolution signal used for? Does the wheel and optical sensor in the distributor not allow the PCM to control everything by itself?

Yeah, I've seen a few examples of people doing this conversion, but there isn't really a how-to posted anywhere.

EDIT: As I'm searching around online, I'm finding that the crank sensor was introduced in 1996 for OBD-II only? 1994-95 (which are the year PCM's I'm after) didn't have the crank sensor??

STL94LT1

Correct.

I have a low mileage opti that I pulled off my 94 a few years ago. I assume it still works. $20/shipped and it's yours.

lt4red

Crank sensor is useless, it detects misfires only, it does not control spark.
High res is for fine tuning injector and spark timing. The spark is controled by the pcm using the input it gets from the opti. The pcm tells the ignition module when to fire the coil.

ULTM8Z

Done! I'm PM-ing you now!