Jump to content
HybridZ

Crank angle sensing


cygnusx1

Recommended Posts

I am no electronics guru and I am just learning about other ignition options with MSII on the 83 L28ET. I am considering eliminating the dizzy and going EDIS. My biggest holdback is the fact that I have A/C in the car, so my front pulley and trigger wheel mounting options are somewhat limited.

 

I have seen the 36-1 trigger cast into some flywheels but I ask does it need to be 36-1?

 

OK here comes the crazy "outside the box" question. Is there any way to make the starter gear teeth on the flywheel act like a trigger wheel? Maybe by grinding off half of a tooth to signal a missing tooth to a sensor. Could MSII read a sensor on the flywheel gear teeth and turn that info into a spark timing trigger for a coil pack? Maybe adding a few magnets to a flywheel could signal an ignition? Any other ideas without messing with the front pulley?

 

Slap me silly if you want to. It's just a dumb question. :icon_frow

Link to comment
Share on other sites

  • Replies 56
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Posted Images

I've not heard of using the teeth, but I know a few people have installed magnets or machined "teeth" into the flywheel opposite of the clutch surface, then simply put the vr or hall sensor through the sheet metal cover on the engine side. A few OEMs do this as well.

Link to comment
Share on other sites

There's a couple ways this can go here...

 

I am no electronics guru and I am just learning about other ignition options with MSII on the 83 L28ET. I am considering eliminating the dizzy and going EDIS. My biggest holdback is the fact that I have A/C in the car, so my front pulley and trigger wheel mounting options are somewhat limited.

 

I have seen the 36-1 trigger cast into some flywheels but I ask does it need to be 36-1?

 

EDIS absolutely requires a 36-1 trigger as the pattern is hard-wired into it. There's a GMDIS system that is similar to EDIS in concept but uses a 7 tooth wheel with a specific trigger pattern that could also work. Again, the tooth pattern is hardwired in there. The MS2/Extra code is under no such restrictions and could use something a bit more arbitrary like a 12-1 wheel.

 

OK here comes the crazy "outside the box" question. Is there any way to make the starter gear teeth on the flywheel act like a trigger wheel? Maybe by grinding off half of a tooth to signal a missing tooth to a sensor. Could MSII read a sensor on the flywheel gear teeth and turn that info into a spark timing trigger for a coil pack?
It's tough to grind a tooth so the sensor wouldn't see it but it would still catch on the starter pinion; a completely missing flywheel tooth would result in a dead spot where if the engine stopped there the starter wouldn't engage.

 

There's been a rather experimental board aimed at BMW and Audi cars that used a flywheel sensor plus a single extra tooth, but I'm not sure how far along that has come. The biggest issue is that the wheel decoding code for MS2 has been aimed at 60 teeth or less.

 

Maybe adding a few magnets to a flywheel could signal an ignition?
Sure, that would work. Same goes for magnets embedded in the crank pulley.

 

Any other ideas without messing with the front pulley?

 

Slap me silly if you want to. It's just a dumb question. :icon_frow

An altered shutter wheel in the distributor, modified to use a pattern that gives cylinder identification, could also trigger a DIS setup.
Link to comment
Share on other sites

this is just an idea. but would a 81 crank pulley work in this situation? i mean it already has the tone ring on there. im not sure of the amount of teeth that are on there though. possibly just use the 81 crank pulley and swap the tone ring.

Link to comment
Share on other sites

OK I made the decision to go with a Ford EDIS-6 ignition system and to mount a 36-1 wheel on the very front of the timing pulley. There seems to be enough room. I am going to use a Dodge coil pack so that I can use regular plug wires.

 

I bought the coil pack and I am shopping for the rest of the parts over the next few days. Meanwhile, I'll study the Megamanual and the changes I'll need to make to the board.

Link to comment
Share on other sites

Thanks, Sidwell. Has anyone run the factory 280Z tach with EDIS-6? Does it work off of pin#2 on the EDIS-6 module or do I need to have a diode party with all three coilpacks -'s?

 

Use the tach output pin on the Megasquirt. I use this with EDIS and it works fine.

 

One thing to keep in mind is shielding of the PIP and SAW signals. Connect the shields at the EDIS module, and leave them unconnected at the MS.

 

Pete

Link to comment
Share on other sites

Dave,

 

One thing to think about when mounting the trigger wheel is where it will be secured to the balancer. You'll want to mount it inboard of the isolation ring. I went crazy troubleshooting ignition for a friend of mine before finding the triggerwheel was ouboard of the isolation ring which was slipping!

 

I had my balancer turned the thickness of the trigger wheel and secured it to the backside of the balancer.

 

Joe

Link to comment
Share on other sites

Great info! I am still gathering parts for the EDIS-6 swap. I'll have to look at the Megamanual about the tacho pin. Didn't know it was there because I have been firing the tach from the negative side of the old ZX coil.

Link to comment
Share on other sites

OK the EDIS-6 swap and head swap is well in progress. EvilC came over last night and we pretty much stripped the engine bay of everything except the long block.

 

I am going to mount the Dodge coil pack to the passenger side firewall. It looks like the Dodge coil pack uses spark plug boot connectors. So the boot you use for the spark plugs are the same that you will use on the coil side. Pretty nifty. I can keep my 8mm wires, cut them shorter, and re-terminate the coil end of them with standard spark plug boots.

 

I am still mulling around wether to mount the 36-1 wheel in front of the crank pulley or behind it. I need to mock it up and measure some things before I decide.

 

The A/C compressor bracket has a BIG boss right near the timing pulley. It is already tapped for a large bolt. I am going to hang my VR senor bracket on that tapped boss.

 

Wiring....well that is always my weak spot, so I am going to go read the megamanual for the 137th time. Jumpers...grounds...shields...I/O's....arrrgh.

Link to comment
Share on other sites

Are you going to remove your A/C compressor? In your first post you say you have an A/C compressor. In your last post you talk about mount the VR pickup to the A/C compressor boss. I don't know where you are going to find room on the compressor side of the engine with the compressor in place. Take lots of pictures. I want to see how you do it. I have A/C as well and wanted to put my VR pickup over there but could not figure out how to do it. I also want to see how you mount the 36 - 1 wheel behind the pulley.

Link to comment
Share on other sites

No I am not removing my AC for crank triggered ignition! The A/C compressor bracket has a forward facing boss on it that is tapped. I am not sure if the bracket is my 76 original or my 83 turbo bracket. I can't remember which one I used. The compressor is the '76 unit. The trigger wheel is getting mounted to the front of the two-row pulley today, using stand-offs on the two extractor tap holes. Once it is mounted and oriented properly to the VR sensor and bracket, I am going to dowel-pin it into place on the outer perimeter of the front pulley flange. I am also going to scale balance all the parts for symmetry before final assembly.

 

I will take photos for sure.

Link to comment
Share on other sites

Thanks for clearing the A/C issue up for me. My bracket does not have the boss you are refering to. If you are going to use the two extractor tap holes, be sure to make very beefy stand offs. Remember the pulley will be spinning up to 6K rpm or over. That would be a very bad time for the trigger wheel to start to wobble.

Link to comment
Share on other sites

I made an alignment tool to center the tone wheel to the hub before I tighten the two stand-off bolts. Once the wheel is in it's final position and the VR sensor is mounted, I am going to pin the tone wheel to the pulley rim, either with dowels or tapped button heads. Trust me, when I am done, it won't move. :coollook:

 

I might have to look at my AC brackets to see why one has the boss and one does not or which is which. Luckily, the boss seems like it's in a good spot to anchor the VR bracket (yet to be fabricated).

Link to comment
Share on other sites

Some photos;

 

Alignment tool, and 6" DIYAutotune 36-1 wheel temporarily mounted, and the fresh P90A solid lifter head all set up and ready to go.

347829915_Aevdt-XL.jpg

The 36-1 wheel is going to be pinned or screwed to the pulley with four machine screws around the perimeter. These will maintain alignment when I put it back on after all the belts are in place during assembly.

 

 

 

Odd boss off the bottom of the AC bracket. I think it's an '83 bracket in aluminum. I think the '76 bracket was iron with no extra boss. Convenient spot for a threaded boss! It even has a stepped edge for alignment. Eliminating the need for a second bolt.

347830039_UuG5A-XL.jpg

 

 

 

The workspace. Our 1.5 car garage.

347830514_odUTE-XL.jpg

Link to comment
Share on other sites

I can confirm that the a/c bracket with the boss(es) is from a zx. I have two of the brackets: one on my 240 and one spare :). Also, I didn't see you mention it but there is another boss exactly like it higher up. Both of them are unused on my 240. I will be following this thread as I have the same dilemma - I live in the Houston area so I must have a/c yet I want edis too!

 

Cheers,

Ross

 

Odd boss off the bottom of the AC bracket. I think it's an '83 bracket in aluminum. I think the '76 bracket was iron with no extra boss. Convenient spot for a threaded boss! It even has a stepped edge for alignment. Eliminating the need for a second bolt.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...