Installing MS-II on 84 Celica with EFI

supermuble · Post by **supermuble** » Wed Aug 02, 2006 7:58 am

I have a 1984 Celica with the first year of EFI. It has a distributor that uses vacuum and mechanical advances, therefore the ignition is not controlled by the computer.

I do not know what type of pickup sensor my distributor uses, whether it is hall or VR. I do not understand the difference. I've read about it many times but I am still confused.

I am considering two options. The first option is to use megasquirt II for fuel only and keep my OEM ignition system that uses mechanical advancing. The 2nd option is to use Megasquirt for ignition.

The problem I have is that the ignition option seems too complicated. I have never owned or tuned a custom EFI system. Has anyone seen MS-II put on a toyota Celica?

See my page to see what I am working with.

http://www.angelfire.com/planet/celica

The car is turbocharged. I have heard and theorized that the wasted spark approach may not be safe for a boosted engine? Is that correct?

thechuckster · Post by **thechuckster** » Sat Aug 05, 2006 7:16 pm

toyota dizzi's use VR sensors - just about all Toyota crank/cam/dizzi sensors are VR.

They generate a current from the toothed wheel moving close by. The sensors are a basically coil of wire wrapped aroung a magnet, the steel passing thru the magnetic field induces a change in that field which in turn induces a current to flow in the wire. Imagine it's a simple generator.

The main issues with VR sensors is that the current is quite low - hence prone to interference - and needs conversion to square wave.

I simply built the VR conditioner circuit from the wheel decoder section:
http://megasquirt.sourceforge.net/extra ... wheel.html
just scroll to the section called "V1.01, V2.2 PCBs VR sense ".

This is the actual circuit:
http://megasquirt.sourceforge.net/extra ... -input.jpg

I use a VR sensor out of a 22RE in a locked dizzi - using it for the trigger for MSnSE install.

There's a growing number of MS and MSnSE installs on Toyota's - read thru the 'Success Stories' sections. Most toyota's seem to be running MSeSE - but there's at least one person on toymods.net/forums/ setting up an 18r-gte with MSII as the ECU.

Waste-spark is fine for turbo (forced-induction) engines - in fact Toyota use waste-spark for the 4a-gze (supercharged 4cyl), 7m-gte (turbo 6cyl), 1g-gze (supercharged 6cyl) and the 1jz-gte/2jz-gte's run the spark in a waste-spark configuration (wires in pairs) despite having coil-on-plug.

cheers and good luck!

charles.

supermuble · Post by **supermuble** » Tue Aug 08, 2006 12:32 pm

It doesn't appear to be a direct process and seems to be overly difficult for a beginner like myself. I am familiar with automotive wiring and modifications to fuel injection, but nothing of this sort.

Thank you for the help! I am pretty certain that Megasquirt Fuel Only would be the best option for me at this time.

http://www.angelfire.com/planet/celica

supermuble · Post by **supermuble** » Tue Aug 08, 2006 12:32 pm

It doesn't appear to be a direct process and seems to be overly difficult for a beginner like myself. I am familiar with automotive wiring and modifications to fuel injection, but nothing of this sort. Thank you for the help! I am pretty certain that Megasquirt Fuel Only would be the best option for me at this time. http://www.angelfire.com/planet/celica
1984 Toyota Celica 22-R Turbo @ 6 PSI. 120 PSI fuel pressure. Hand made down pipe. Nissan Turbocharger.
-------------------- m2f -------------------- This post is at: http://www.msefi.com/viewtopic.php?p=135326#135326 -------------------- m2f --------------------

Posted by email.

thechuckster · Post by **thechuckster** » Thu Aug 10, 2006 7:52 pm

you've got all the bits you need to run fuel-and-spark.

the only major mod is locking the dizzi - MSII has the VR interface on the board and you've already got the other EFI hardware in place.

it will be a far more tunable setup that relying on increased fuel pressure to cope with on-boost fuel requirements.

fuel-only is the ideal starting point, but spark control will give you back control over your engine.

cheers,
Charles.

rs2000 · Post by **rs2000** » Thu Aug 10, 2006 8:58 pm

thechuckster wrote:MSII has the VR interface on the board

I don't think thats right, the V3 board has the interface - so you could use ms1 or ms2. ms1 or ms2 on a V2.2 board will not have the interface

thechuckster · Post by **thechuckster** » Fri Aug 11, 2006 1:48 am

sorry, was assuming supermuble had a V3 board with MSII code