OEM crank trigger for aftermarket EFI
OEM crank trigger for aftermarket EFI Hey, Gents,
In anticipation of the Mega Squirt 2/Extra code being released relatively soon (well it will probably be released before I am ready to start my engine) I would like to know if anyone knows which two wires on the CKP sensor are required to get an equidistant 24x pulse signal out? Also has anyone scoped the output of the LS2 cam trigger? Based on pictures of the cam gear and the location of the sensor in the front cover, it looks like it is lined right up to trigger @ TDC # 1 (or slightly prior to it). The trigger "tooth" is exactly 180 degrees which equates to one complete cranskaft revolution. Also any idea what the third wire is for on the cam sensor? I was under the impression that you needed only two wires to generate a VR pulse.
In anticipation of the Mega Squirt 2/Extra code being released relatively soon (well it will probably be released before I am ready to start my engine) I would like to know if anyone knows which two wires on the CKP sensor are required to get an equidistant 24x pulse signal out? Also has anyone scoped the output of the LS2 cam trigger? Based on pictures of the cam gear and the location of the sensor in the front cover, it looks like it is lined right up to trigger @ TDC # 1 (or slightly prior to it). The trigger "tooth" is exactly 180 degrees which equates to one complete cranskaft revolution. Also any idea what the third wire is for on the cam sensor? I was under the impression that you needed only two wires to generate a VR pulse.
Ok Gents, I found this document on the web. It's from Holden but they are all pink on the inside 
Pages 30 and 32 contain a graphical display of the on and off pattern of the LS1 trigger wheel. It also has the wiring diagram of the sensors but unfortunately It is beyond me to decipher.
Holden diagnostic Manual
Pages 30 and 32 contain a graphical display of the on and off pattern of the LS1 trigger wheel. It also has the wiring diagram of the sensors but unfortunately It is beyond me to decipher.Holden diagnostic Manual
The know it all's know it all
Joined: Oct 2006
Posts: 500
Likes: 0
Originally Posted by 96 Comp T/A
Thanks for the tip. I am not interested in spending $2500+ on an engine controller.
Yes you can. I have heard that this has been done already at least once, but nothing has been documented yet, at least publicly. If you are not familiar with MegaSquirt, you can check them out at www.megasquirt.info This thing can and will will run just about anything from turbocharged 2-stroke banshees to 1000+ horse LS1's. It's got some some features that even the 3k plus controllers don't. It is a modular design utilizing CAN networking for expansion modules that will provide extra I/O from sensors or devices. It's easy to use and development is basically open to whoever feels like writing code for it. It's easy to use and did I mention it costs around $350 (unassembled)?
After doing some reading in that holden document it looks like the trailing edge is the ticket. (all trailing events are at even 15 degree increments and 360/24 is 15). I was initially under the impression that because of the two different wheels (sandwiched together) on the back crank that their were two different VR signals being sent to the PCM and the PCM was using a differential equation to determine crank angle. Thanks to the power of google this does not look to be the case now.
Trending Topics
The know it all's know it all
Joined: Oct 2006
Posts: 500
Likes: 0
Originally Posted by 96 Comp T/A
After doing some reading in that holden document it looks like the trailing edge is the ticket. (all trailing events are at even 15 degree increments and 360/24 is 15). I was initially under the impression that because of the two different wheels (sandwiched together) on the back crank that their were two different VR signals being sent to the PCM and the PCM was using a differential equation to determine crank angle. Thanks to the power of google this does not look to be the case now.
Your welcome hint, sorry i forgot which edge though,
but i am glad i didn't have to measure a wheel. Yes the MS is a nice piece i remember efi332 if you want to go way back in DIY-EFI. LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
