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The Woes of Optispark (updated)


The 1994 LT1 in Brutus uses a Gen 1 "unvented" Optispark, this means it has no vent holes, meaning moisture collects and that leads to Optispark failure.  This is a well known problem, some cars go 200,000 miles with no issue while others a subject to replacement after replacement.  I believe the issues of the engine from last week's drive are just that, Optispark issues, it matches most of the symptoms:

  • Car suddenly dies and won't restart
  • Starts but immediately dies
  • Extended cranking to start
  • Rough idle
  • Sputtering
  • Backfiring
  • Trouble reaching higher rpm
  • Black smoke from exhaust
  • Poor performance with car warmed up
  • Weak plug wire spark
  • Codes 16, 36, and 42 may be set
 
More information on the above can be found at GM High-Tech Performance.
 
So I've been researching what to do about this.  Buy another $300 Opti and cross my fingers, or fix the problem once and for all.  I could change the Opti to a "Gen-II" which has better vent holes but that's not a small change, new timing set, new cam, timing cover etc etc.  It's not a 5 second thing and no guarantee.  

So replacing the Optispark with something that will stay reliable is the goal.  Here are the 4 options I've come up with: 

  1. Megasquirt with a Crank Trigger driving a Ford EDIS-8 Ignition, replaces the Optispark completely.  However the Megasquirt isn't for the faint of heart programming wise. I think I can do it but worry it will take MUCH longer than I expect. About $800cdn.
  2. Aftermarket complete Optispark unit called a Dynaspark. This is a completely redesigned Optispark that apparently solves the moisture problems of the Opti.  I'm just not fully convinced but it does come with a 12 month warranty and can be rebuilt by Dynaspark for $36.  Cost $650cdn.
  3. Delteq, this takes the high voltage out of theOptispark but would require a new Optispark since the one on the car is buggered.  Not an ideal solution but better than just replacing the Opti.  $800cdn including an "Ebay Optispark. http://www.delteq.com/
  4. Delteq+DynaSpark: Dynaspark makes the Optispark replacement designed specifically for the coil of the Delteq.  It's an Opti with just the optical signal, nothing else. Delteq+Dynaspark-III $1300

 I really want to do the Megasquirt and believe the Megasquirt is the best option, but worry about the programming.  There are many other benefits to the Megasquirt too, like data logging etc.  I've read a great deal, and this isn't a small project.  My worry here would be having trouble and not getting the car ready in time for spring not to mention never being happy with the tune and always fiddling with it.  This isn't just an ignition change but a complete change to the car's computer, that means wiring changes, etc.  I'm sure I can figure it out, I just worry if I can do it quickly enough and will be happy with the final product. 

If you have any other ideas, or have tried any of the above combinations I'd love to here about them in the comments below.  Likewise if you know about a shop in the Toronto area that knows Megasquirt well, let me know.

Update: Two other options have been discovered:

1) LTCC, similar to the Delteq system except 8 LSx coils.  Cost ~$650 including LSx coil packs. http://www.bailey-eng.com/LTCC.html

2) EFI Connection 24x kit with the required parts to swap out the LT1 ECM for the LS1 PCM.  Kit includes cam reluctor new timing cover, crank reluctor, and requires a harness modification and new LSx computer.  Cost for the "kit" is $525 and requires a harness ($650 or DIY $100) and LS1 PCM ($100) + LS1 coils (~$250 OEM).  This sounds like a happy medium between Megasquirt and Delteq/LTCC.  Assuming I can figure out the harness. http://www.eficonnection.com/24x/

This means I have 6 options. I like the idea of the EFI Connection 24x but again worry if I will run into problems, if that is going too far…Current thinking is either the LTCC options, the Dynaspark alone or the EFI Connection… 

Posted in Parts.


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