0versteer
0versteer New Reader
7/21/15 11:58 p.m.

I have a toyota 22r i want to be able to program timing advance.

i've already done a fair amount of research and came up with the usual suspects, all out of budget of course.

im a fan of ecu hacking, so that would be a cool way to go.

i really want to stay with the distributor, i racked my brain for hours trying to find a way to mount a trigger wheel on this motor.

Any ideas...?

Trackmouse
Trackmouse Reader
7/22/15 1:15 a.m.

22r? Must be a Celica. Head over to celica-gts.com. We will take care of you over there. Gotta truck? Bleh.

Dusterbd13
Dusterbd13 UltraDork
7/22/15 6:42 a.m.

Carb or efi?

dean1484
dean1484 MegaDork
7/22/15 6:58 a.m.

Megga jolt lite Jr From Autosports Labs. You will need to adapt a EDIS box, trigger wheel, sensor, ford coil pack. All junk yard items. Makes your ignition completely programmable. I converted my 924s to this and had 150k trouble free miles.

It is made by the same great people that make Race Capture. I am not sure that the original MJLJr is still available. You can check with them and see.

MadScientistMatt
MadScientistMatt UberDork
7/22/15 8:01 a.m.

You can use an MS1 V2.2 kit to control the factory VAST ignition from a 22RE. This write up is for a 4AGE, but the 22RE ignition is similar.

http://www.diyautotune.com/tech_articles/how_to_megasquirt_your_mki_toyota_mr2.htm

rcutclif
rcutclif Dork
7/22/15 10:16 a.m.

looks like ms1 v2.2 kit is $169. But does this really come with everything necessary to run the engine (assuming you already have the engine)?

It seems like you would really need to spend some more money to get the trigger wheels/sensors, etc to complete the build, yes?

I have been asking myself a similar question recently as I have some desire to back-date an EFI car to carbs, but I know there isn't an ignition solution for the engine that isn't the stock computer.

erohslc
erohslc Dork
7/22/15 10:55 a.m.

Autosport shows bare bones Megajolt/E at $144.95
You'll also need some EDIS stuff, eBay has that, and fit a timing wheel somewhere.

http://www.autosportlabs.com/product/megajolte/

rcutclif
rcutclif Dork
7/22/15 11:43 a.m.

so, pardon my ignorance, but what is the EDIS module needed for? My understanding:

  • timing wheel tells the megajolt where the engine is in its rotation
  • megajolt contains the timing map (based on RPM and load), and says when each plug should fire
  • EDIS... um... opens the points? Converts the megajolt signal to something a coil can understand?

If all the EDIS needs to do is break a circuit on command (to fire a coil), then shouldn't we be able to make a circuit do the same thing really easily? Or does the megajolt only output an 'advance' number and the EDIS then handles the 'distributing' work too? If that second option is the case, and my engine uses a distributor rotor and cap, can I skip the EDIS?

turboswede
turboswede MegaDork
7/22/15 11:56 a.m.

MSExtra code can drive the coils directly with the addition of some coil driving circuitry. Tach signal may need circuitry to work with the stock tach (The EDIS module provides a pretty useful tach signal). Bonus is the ability to support a wider range of trigger wheels and more finite control of dwell time.

http://www.msextra.com/doc/index-ms1.html

MegaJolt is written and designed around using the EDIS module as it has been on the market for quite sometime.

http://www.autosportlabs.net/MegaJolt_Lite_Jr.

rcutclif
rcutclif Dork
7/22/15 12:27 p.m.

so, if I'm understanding correctly:

  • MS1 v2.2 ($169 for the kit) can drive the coil directly with an additional $8.50 transistor circuit. You could run wasted spark for $8.50 per 2 cylinders. No EDIS or trigger wheel needed (assuming your stock cam or crank angle sensor works).
  • MS1 v3.0 ($219 for the kit) can drive the coil directly with no additional transistor circuit (they are included). I assume this includes enough transistors to run up to 12 cylinders in wasted spark mode.
  • MegaJolt ($145 most basic) but needs the EDIS module as well - also assuming your stock cam or crank sensors work.

Seems like you might as well go MS1 because for a few extra bucks you can also do all the fuel control...

turboswede
turboswede MegaDork
7/22/15 12:44 p.m.

In reply to rcutclif:

Yup! and if you want to use your disty, you can do that too.

0versteer
0versteer New Reader
7/22/15 4:03 p.m.

In reply to Trackmouse:

Truck, unfortunately. haha

0versteer
0versteer New Reader
7/22/15 4:08 p.m.

i really would like to go the EDIS route, i already have an edis 4, trigger wheel, and vr sensor... the problem is i just for the life of me cant find a way to mount the 36-1 trigger wheel..

i would like to do a 72-2 wheel on the dist, anyone done that reliably?

im also interested in hacking GM ecu's to run just my dizzy.. i have a honda ecu and i played around with building a hybrid honda/toyota distributor.. but i dont have a lathe to turn down the rod needed to graft them together.. :/

by the way, this is a 1985 toyota pickup i rebuild, 22r, weber 32/36, etc etc..

i have a 22re non vacuum distributor, and a 22r vacuum distributor.

erohslc
erohslc Dork
7/22/15 4:59 p.m.
rcutclif wrote: so, pardon my ignorance, but what is the EDIS module needed for? My understanding: - timing wheel tells the megajolt where the engine is in its rotation - megajolt contains the timing map (based on RPM and load), and says when each plug should fire - EDIS... um... opens the points? Converts the megajolt signal to something a coil can understand? If all the EDIS needs to do is break a circuit on command (to fire a coil), then shouldn't we be able to make a circuit do the same thing really easily? Or does the megajolt only output an 'advance' number and the EDIS then handles the 'distributing' work too? If that second option is the case, and my engine uses a distributor rotor and cap, can I skip the EDIS?

The EDIS unit drives the coils and so controls spark based on timing signal from 36-1 wheel/sensor.
The missing tooth in the wheel lets it figure out where TDC is.
Advance is set by SAW (Spark Advance Word) signal.
In limp mode (no SAW) it defaults to fixed 10 BTDC.
The SAW is normally generated by the ECU along with with injector pulsewidth, etc.
But anything can generate the SAW, it's a simple signal, pulsewidth determines advance.
Megajolt is a standalone unit that does the job, just for ignition.

The EDIS will not run on a points signal.

turboswede
turboswede MegaDork
7/22/15 5:19 p.m.

In reply to 0versteer:

Got a steel crank pulley? You could cut the notches or teeth into the edge of the pulley using a milling machine and a rotary table.

Most buy a generic 36-1 pulley and have an adapter turned to mount it to the front of the engine or the front pulley.

That's actually the easy part, mounting the pickup can sometimes be more tricky.

A 72 tooth pulley in the distributor has been done and it works ok. Then again you might be able to drive it directly without EDIS.

erohslc
erohslc Dork
7/22/15 6:12 p.m.
turboswede wrote: In reply to 0versteer: Got a steel crank pulley? You could cut the notches or teeth into the edge of the pulley using a milling machine and a rotary table. Most buy a generic 36-1 pulley and have an adapter turned to mount it to the front of the engine or the front pulley. That's actually the easy part, mounting the pickup can sometimes be more tricky. A 72 tooth pulley in the distributor has been done and it works ok. Then again you might be able to drive it directly without EDIS.

Yes, but if using EDIS, that would need to be a 72-2 wheel in the dizzy, since missing tooth is how EDIS derives TDC.
Also smaller pulleys demand more tooth precision to maintain timing accuracy.
A 4" 36-1 diameter pulley = 0.349"/tooth, a 2" 72-2 diameter pulley = 0.0872"/tooth.
As well, mag pickups are sensitive to tooth velocity, may encounter signal dropout at lower RPM.

I'm sure folks have made it work, just not sure why they bothered.

djsilver
djsilver Reader
7/22/15 7:08 p.m.

Check the insides of an 80's-90's Nissan to see if you can reuse the parts. They're actually called "camshaft position sensor" in Nissan talk. It has a plate inside with 360 1 degree slots and 4 90 degree slots, one of which is wider for the TDC mark. It uses an LED light source and a light detector to determine rotation position. However, a trigger wheel on the crankshaft is the most accurate, as it doesn't have to deal with the slop in the camshaft belt/chain.

dean1484
dean1484 MegaDork
7/22/15 7:49 p.m.

I am running a 72-1-1 on the cam of the 924s with no issues. Used a 72 tooth spur gear and made my own. I used the pickup out of an rx7 FC

Trackmouse
Trackmouse Reader
7/22/15 9:12 p.m.

Honestly. If you are going to go through all this trouble, just buy MS1. It is loads better than the garbage Ecu from the 80's. I was going this route. That's is, right until I found a 1uzfe donor...

erohslc
erohslc Dork
7/22/15 9:17 p.m.
djsilver wrote: Check the insides of an 80's-90's Nissan to see if you can reuse the parts. They're actually called "camshaft position sensor" in Nissan talk. It has a plate inside with 360 1 degree slots and 4 90 degree slots, one of which is wider for the TDC mark. It uses an LED light source and a light detector to determine rotation position. However, a trigger wheel on the crankshaft is the most accurate, as it doesn't have to deal with the slop in the camshaft belt/chain.

That's good to know, but that setup will not work with EDIS hardware.
The EDIS electronics inside are what they are.
It will not decode those 360 slots, 4 90 degree slots, and 1 wider slot to figure out TDC.
It will not interface to a light trigger.
But maybe if you are a bithead/electron jockey you can munge some Nissan parts to work on your 22r.

Vigo
Vigo PowerDork
7/22/15 9:23 p.m.
If all the EDIS needs to do is break a circuit on command (to fire a coil), then shouldn't we be able to make a circuit do the same thing really easily?

Well, when the circuit's NOT broken it's flowing several amps per coil, so there has to be a fair amount of heat dissipation involved. The whole function of an 'ignition module' in the most basic sense is to house a bunch of high current transistors and somehow shed the heat. If it werent for the current/heat requirement you could use a single microscopic transistor buried in a computer board to control the ground side of a coil primary winding, but alas.

MadScientistMatt
MadScientistMatt UberDork
7/23/15 7:27 a.m.
rcutclif wrote: looks like ms1 v2.2 kit is $169. But does this really come with everything necessary to run the engine (assuming you already have the engine)? It seems like you would really need to spend some more money to get the trigger wheels/sensors, etc to complete the build, yes? I have been asking myself a similar question recently as I have some desire to back-date an EFI car to carbs, but I know there isn't an ignition solution for the engine that isn't the stock computer.

This assumes that (1) you build your own harness, and (2) you already have a VAST distributor and ignition module (the MS1 will use that to control timing). You might also need to add a cable to connect to your laptop if you don't already have one.

I would only use an MS1 V2.2 if you had specific sorts of computer controlled ignition. Toyota's VAST, Ford's EDIS and TFI, and GM's computer controlled HEI are ones that are pretty easy to use the MS1 V2.2 with. And the Toyota 22R happens to have the VAST as a factory option. For most other applications, I'd step up to a V3.0 board.

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