Toyota VAST ignition and MS-II

ivanlau78 · Post by **ivanlau78** » Thu Aug 03, 2006 1:48 pm

does any one success running 4age with new beta code?

dcg9381 · Post by **dcg9381** » Wed Aug 09, 2006 9:11 am

So I've read over the information provided by lance and other contributors:
http://www.megamanual.com/ms2/vast.htm

I'm doing a 1988 Toyota 4runner (22re) that uses VAST as OEM.

Some hardware changes are needed to accept square wave 12v.

Output again requires some harware changes to provide enough current to the ignitor...

It is interesting to note that the ignition system should start and run with base timing, without any signal... A good starting point.

My relative newbie questions are:
1) Is there any advantage to running a crank triggered sytem (hall effect) with more teeth on it other than increased resolution and timing accuracy?

2) Will a typical hall effect crank trigger system require hardware changes as it's not square wave?

Seems to me that you could almost build a plug and play adapter between megasquirt and toyota TCCS (other than dealing with the OEM tach).

dcg9381 · Post by **dcg9381** » Wed Aug 09, 2006 9:11 am

So I've read over the information provided by lance and other contributors: http://www.megamanual.com/ms2/vast.htm I'm doing a 1988 Toyota 4runner (22re) that uses VAST as OEM. Some hardware changes are needed to accept square wave 12v. Output again requires some harware changes to provide enough current to the ignitor... It is interesting to note that the ignition system should start and run with base timing, without any signal... A good starting point. My relative newbie questions are: 1) Is there any advantage to running a crank triggered sytem (hall effect) with more teeth on it other than increased resolution and timing accuracy? 2) Will a typical hall effect crank trigger system require hardware changes as it's not square wave? Seems to me that you could almost build a plug and play adapter between megasquirt and toyota TCCS (other than dealing with the OEM tach).
1981 Toyota 22r Supercharge
-------------------- m2f -------------------- This post is at: viewtopic.php?p=135460#135460 -------------------- m2f --------------------

Posted by email.

katok · Post by **katok** » Thu Aug 17, 2006 4:30 pm

Hi Lance,

Is the toyota igniter control the dwells?

katok · Post by **katok** » Thu Aug 17, 2006 5:26 pm

Lance wrote:katok,

As far as I am aware, the toyota igniter used with the VAST system does not control the dwell, it relies on the ECU to do this.

Lance.

thanks for that information lance.

i'm about to set-up my MS2 to a 4age using JDM igniter.

ivanlau78 · Post by **ivanlau78** » Sat Aug 19, 2006 10:47 am

katok wrote:
Lance wrote:katok,

As far as I am aware, the toyota igniter used with the VAST system does not control the dwell, it relies on the ECU to do this.

Lance.

thanks for that information lance.

i'm about to set-up my MS2 to a 4age using JDM igniter.

any update on your 4age MS2 setup? can you let me know your 4age is 16v or 20v?

katok · Post by **katok** » Sun Aug 20, 2006 6:43 am

ivanlau78 wrote:
katok wrote:
thanks for that information lance.

i'm about to set-up my MS2 to a 4age using JDM igniter.
any update on your 4age MS2 setup? can you let me know your 4age is 16v or 20v?

my engine is 16v engine (tvis)
i will start my project in a few weeks from now

ivanlau78 · Post by **ivanlau78** » Tue Sep 12, 2006 4:53 am

have you start your project?

ivanlau78 · Post by **ivanlau78** » Tue Sep 12, 2006 4:53 am

have you start your project?

Posted by email.

ivanlau78 · Post by **ivanlau78** » Sat Sep 16, 2006 12:13 pm

phydeaux wrote:Are their any advantages to using vast over just driving the coil with the ms2?

Currently I have the NE signal going right in to the ms2's vr circuit and am driving the coil with the vb921. I still have all of the vast stuff sitting in a box somewhere and am at a point in the project where if I want to make a change like this its a good time to do it. I've started and run the engine for a little bit in its current configuration and didn't have any problems but the car's not road worthy so I haven't put any sort of load on it yet. The engine is a 4agze fitted with a 4age distributor that has a 4 tooth NE wheel.

andy

can you post your MSQ file?
which version of ms2 you running? i have problem to take signal from 4 tooth. the signal not stable. 4age NE signal should be 24 tooth, 4 tooth is G1.
i'm trying to do fuel only, but still hard to make the engine idle. not sure what's wrong with injector setting.

ivanlau78 · Post by **ivanlau78** » Fri Oct 06, 2006 9:31 am

no one done yet?

dcg9381 · Post by **dcg9381** » Sun Oct 22, 2006 7:46 pm

phydeaux wrote:Are their any advantages to using vast over just driving the coil with the ms2?

andy

Yes.
On some Toyota vehicles - OEM tach and AC pull up are also dependent upon output from the VAST system. NO vast = no tach and no ac without other mods.

dcg9381 · Post by **dcg9381** » Mon Oct 23, 2006 6:49 am

This is where you get to ask for vehicle specific information.. I know it's not driven from the negative coil on the pickup/4runner. Guys using megasquirt and swapping in an MSD ignition system have to "condition" the tach output of the MSD so it can be accepted by the OEM tach. I don't know much about the circuit because I haven't ever done it.. PM me if you need more information - I think I've got an email somewhere with the part number.

ivanlau78 · Post by **ivanlau78** » Tue Oct 24, 2006 3:23 pm

JDM 4age 16v running ESA, NE, G and G- direct to ECU, not to igniter. NE comes with 24 tooth and G come with 4 teeth. I have try using G on a drill machine and get nice RPM signal without problem. Will try 12-1 soon.

What's the different of using 1k instead 220 ohms resister?

dcg9381 · Post by **dcg9381** » Wed Oct 25, 2006 7:48 am

Notes:
1) ESA is NOT VAST. My post doesn't apply to the ESA system.
2) The toyota FSM are not very good about the use of the term "ESA" - they use it as a "generic" term in my FSM.. Electronic Spark Advance when it's actually a VAST system. (just FYI) - the only way to know for sure is to look in the dizzy or understand the system.

For the VAST system, here's an outline of the input circuit.
The 220ohm resistor changes the square wave to be at 4v instead of 2.5v with a 1k ohm. According to my scope on a factory ECU, the ignitor expects 4v. Note, it's been done successfully with the 1k ohm.

ivanlau78 · Post by **ivanlau78** » Sun Nov 05, 2006 2:02 am

update on input trigger,
tried JDM 16v 12-4 which 12 is NE and 4 is G. i use 4 tooth G signal will work on both VR and Hall input circuit.
tried JDM 20v 12-1-1 which 12 is NE, G1 and G2. i use 12 tooth NE, cut 2 out opposite as 12-1. only work on VR circuit.

both distributor signal connect direct to MS2, not to ignitor. 12-1 is more stable, signal spike less then 10 rpm. for 4 tooth, signal spike around +-30 rpm.

will try ignition output soon.

ivanlau78 · Post by **ivanlau78** » Mon Nov 13, 2006 2:48 pm

tested direct coil control, its work. i get input signal and output spark. but vb921 fried few min after cause wire directly without fuel pump relay.

MSefi.com read only forum (Jan.15,2018)