MS with 4A-GE Blacktop in AE86 project

[Fii]

Hi!

I am starting a project of swaping the 4A-GE blacktop engine in my AE86 this winter. The engine just arrived, however it is missing some parts. First of all, there is no ECU, so I am going to use the MS. Then, the distributor is missing, but since the engine with distributor will not fit into the AE86 engine bay without firewall modifications, I would like to migrate to direct ignition. The problem is to find an appropriate cam pickup. So far it seems that the distributor from 4A-FE or 3S-GE engine might fit on the camshaft. The plan is to convert the distributor into the cam position sensor, to feed the signals to MS (This should also solve the fitment problem). I could not find any out of the box CPS from other Toyota engine, which could be used directly. But this should not be a problem since I have seen some people here, who have successfully used 3S distirbutor for pickup.
And finally there is no IAT sensor, but that should be easily replaced with GM one.

I am targeting for MS2 on v3.0 board, but will probably start with MSNS-E and old processor on v3.0 board until the software is ported to MS2.

I would like to have the following features:
Fuel control for all 4 injectors
Since MS has two injector drivers it seems that I should split the injectors in 2 groups of 2 injectors and fire them in batches. I believe they are low impedance injectors, but the MS should be able to hande two of them per channel.

Ignition control for 4 spark plugs
Wasted spark, so I need 2 ignition outputs. What can I use for the second output?
I have an ignitor and coil packs from 7M engine.
Is it possible to use the coils directly with MS, or should I also use the ignitor? The problem with ignitor is that it takes 3 signals as input, I could probably get it working with 2 signals for 4cyl engine. It takes one signal when to fire and the second signal denotes, which coil to fire, so I need to skip the second signal for every second ignition event. It would be easier to just fire one or the another coil directly from ECU.

IAC stepper motor control
MS2 should provide that out of the box.

VVT control
One output as on/off switch, based on RPM, but ideally also on load.


What do you think about my plans, will this work?
Am I missing something important?

[superchargingmachine]

There are many options. I know people have used factory distributors as a pickup but I don't have experience with those setups. See the link below for pictures of hwat I did to run distributorless with MSnS-Extra(controlling Ford EDIS).

http://www.geocities.com/superchargingm ... SnEDIS.zip

You should be able to create a simple circuit to control VVT based on RPM without too much fuss.

But like I said there are a lot of different way to get this done and it largely depends on what you think will work best for you.

[muythaibxr]

Hi!
I am targeting for MS2 on v3.0 board, but will probably start with MSNS-E and old processor on v3.0 board until the software is ported to MS2.

I'm going to be doing a very similar installation on my ae86 with a silver-top 20v soon, also using the distributor as a cps. You are correct that the ms2 does not yet have any code for wheel decoding, so you'd definitely have to go with msns-extra to begin with.

I would like to have the following features:
Fuel control for all 4 injectors
Since MS has two injector drivers it seems that I should split the injectors in 2 groups of 2 injectors and fire them in batches. I believe they are low impedance injectors, but the MS should be able to hande two of them per channel.

They're high-impedance injectors unless they changed from the silver top to the black top, and the ms will have no problem controlling either one, especially with the v3 board.

Ignition control for 4 spark plugs
Wasted spark, so I need 2 ignition outputs. What can I use for the second output?
I have an ignitor and coil packs from 7M engine.
Is it possible to use the coils directly with MS, or should I also use the ignitor? The problem with ignitor is that it takes 3 signals as input, I could probably get it working with 2 signals for 4cyl engine. It takes one signal when to fire and the second signal denotes, which coil to fire, so I need to skip the second signal for every second ignition event. It would be easier to just fire one or the another coil directly from ECU.

You'd be better off using a couple of vb921's to directly charge/fire the coils. The ignitor design is very similar to the trailing ignitor on an rx7, but I'm not sure anyone has written code to do that kind of output. What I'm going to do is take 2 rx7 leading coils/ignitors and drive each with its own advance signal instead of that goofy "IGt/Coil select" setup. The LED's on the front of the MS are used as signal outputs, you just solder a pullup resistor to each led's negative lead, and to a +5v source, and then solder the output wire to the negative lead of the LED also.

IAC stepper motor control
MS2 should provide that out of the box.

As far as I know, the 20v's don't use a stepper motor, they use a 3 wire PWM IAC valve. msns-extra can control this, as well as ms2.

VVT control
One output as on/off switch, based on RPM, but ideally also on load.

For this you want one of the extra outputs driving a transistor which turns off/on the solonoid that turns on VVT. In other words this should be no problem.

What do you think about my plans, will this work?
Am I missing something important?

It should work fine. I'm planning on doing many of the same things in the next month or 2.

Ken

[Fii]

Thanks guys!

You'd be better off using a couple of vb921's to directly charge/fire the coils. The ignitor design is very similar to the trailing ignitor on an rx7, but I'm not sure anyone has written code to do that kind of output. What I'm going to do is take 2 rx7 leading coils/ignitors and drive each with its own advance signal instead of that goofy "IGt/Coil select" setup. The LED's on the front of the MS are used as signal outputs, you just solder a pullup resistor to each led's negative lead, and to a +5v source, and then solder the output wire to the negative lead of the LED also.

Do I need one or two additional vb921 circuits? As I understand from docs, the v3.0 board has one already integrated.

As far as I know, the 20v's don't use a stepper motor, they use a 3 wire PWM IAC valve. msns-extra can control this, as well as ms2.

Seems that you are right, I have not looked into this deeply enough. Do I need some additional circuit for controling this IAC valve? As I understand the inputs for valve are 12V power and two PWM signals. How do I hook it up to MS?

Is there some common practice for selecting which inputs/outputs use for what functionality? Or everyone does as sees fit?

[muythaibxr]

Thanks guys!
Do I need one or two additional vb921 circuits? As I understand from docs, the v3.0 board has one already integrated.

It does, but I believe it uses a different CPU pin if you wire it up normally because it's meant for use with the ms2... you should wire it to one of the cpu outputs that normally drives the LEDs, and then wire up the second one the same way, or you can just not use the one that comes with the v3 board and get 2 more and wire those both up to the cpu's led outputs.

Seems that you are right, I have not looked into this deeply enough. Do I need some additional circuit for controling this IAC valve? As I understand the inputs for valve are 12V power and two PWM signals. How do I hook it up to MS?

There is a diagram here:
http://megasquirt.sourceforge.net/extra/pwmidle.html

it's the 3 Wired Bosch Valves (0280 140 505) diagram.

Is there some common practice for selecting which inputs/outputs use for what functionality? Or everyone does as sees fit?

Well, for the VVT, you'd just pick one of the generic outputs.

[lmr052]

Seems that you are right, I have not looked into this deeply enough. Do I need some additional circuit for controling this IAC valve? As I understand the inputs for valve are 12V power and two PWM signals. How do I hook it up to MS?

There is a diagram here:
http://megasquirt.sourceforge.net/extra/pwmidle.html

it's the 3 Wired Bosch Valves (0280 140 505) diagram.

I use a different cicuit for my 3SGE 3 wire IACV - which is probably the same as the 4AGE. I think it was scirturbo who devised it. It has 2 power FETs, a pair of diodes an extra 2n2222 and a couple of resistors, plus I added 4 x 2R2 1W resistors to limit current (as per the OEM setup which has 2 x 1R0 2 watt resistors). I can send a copy or you may be able to search for the Inverted PWM idle thread on this section of the forum (from memory - if it is still on line). I recomend you invest the time and effort to use the IACV as it is great to be able to have MS control idle.

If you are tight on space at the back of the head, then maybe a toothed wheel on the crank pulley or fabricate a cover for the distributor and convert it to a CPS.

In summary, your plans are entirely feasible.

Regards, Richard

[Fii]

I have found the Inverted PWM Idle Control thread.
It has the following schematics in it:


Toyota docs has the following diagrams:

It seems pretty much the same schematics as above.

There are no resistors in Toyota diagrams. However it is possible that they considered them irrelevant for diagrams and did not draw them.
Where exactly do you use the resistors?

If I understand correctly then MS is configured to output an PWM signal to FIdle output and using this circuit it controls the idle.

[Fii]

There is also one more diagram in that thread. Which one would be better for me and why?
http://www.msefi.com/download.php?id=1121

[slow_hemi6]

They are both the same thing.One has a transistor inverter stage and the other uses an inverting IC.

[Fii]

They are both the same thing.One has a transistor inverter stage and the other uses an inverting IC.

Yes, but which one is better/cheaper/more reliable?

[ulrichf]

Hi Fii

I would go for the transistor version - it is by far the cheapest, and in my opinion it is the best one as well.

the transistor version will drive the fets by 12v versus 5v from the inverter, this makes for less heat from the fets as they are turned on properly.

and secondly (third ??) less complicated parts = more reliability in my book.

Ulrich

[KaNaDa]

I will need to build this to drive the original bosh 3 whire I have in my BMW.
Is heat any concern? can this be built in the proto area of the V3 board?

http://www.msefi.com/download.php?id=1121

If I understant it corectly the R3 connects to MS FIDLE output?

thanks,

[ulrichf]

Actually if you are using the V.3 board the "IDL" output is equal to the X2 socket in the diagram.

You should have no problem fitting the circuit in the proto area.
- the heat issue depends interely on the fets you are using - I have used some IRF840´s I had laying around, to drive an idle valve on an E28 BMW - even without heatsink there is no noticable heating of the fets.

Ulrich

[lmr052]

There is also one more diagram in that thread. Which one would be better for me and why?
http://www.msefi.com/download.php?id=1121

This is the one I use with the added 4 x 1W resistors in the RSO, RSC. An earlier version had one of the FETs drawn incorrectly.

It works for me. Heat is not a problem in that the FETs are not heat sinked and seem to work OK. In the OEM ECU, the transistors are not on a heat sink either on the Toyota set up.

Yes, the R3 connects to the MS FIDLE. Then you select the Fielding PWM option in MT.

Regards, Richard

[KaNaDa]

R4 & R5 says 22 is that 22k or 22 ohms? I am still illiterate in eletctronic circuits, allthough working on it ;)

lmr052 do you have the schematics of the changes you made ?

thanks,

[lmr052]

R4 & R5 says 22 is that 22k or 22 ohms? I am still illiterate in eletctronic circuits, allthough working on it ;)

lmr052 do you have the schematics of the changes you made ?

thanks,

Hey this is all about learning ... and this is how you learn 22 is 22 ohms.

No schematics as the latest one in the thread is OK and my mods simple. My OEM Toyota ECU has 1 ohm 2w resistors on the inputs from the IACV. I couldn't buy these resistors easily so I improvised by using 2 x 2R2 (ie 2.2 ohm) 1W resistors in parallel to give me 1.1 ohms at 2 watts. did this for both IACV wires.

I don't believe scirturbo used these resistors on his Bosch setup though. They may be unnecessary but I figured they would do no harm.

Regards, Richard

[jamesawooten]

I'm working on a Silvertop installation in an 86 MR2 using MSII with the V3 main board.

Since MSII doesn't (yet) support wheel decoding, is it feasible to take the 24 tooth wheel in the Silvertop distributor and grind down all but 4 teeth, then feed the signal into the VR sensor circuit built into the V3 main board?

Then I could use the V3 High Current Ignition Driver to drive the stock MR2 coil directly.

It seems that this would be the simplest solution.

[Fii]

After a while I am back to the project. I have got a distributor base from another Toyota engine (I don't know which one), which physically fits my engine. I would like to use it for pickup in order to run wasted spark coils directly from MS.

The distributor has two wheels:
1) 4 tooth wheel with two VR sensors 90 degree apart, which seems to be connected in series to output one signal to ECU (red, white; bottom green wire connects both sensors).
2) 1 tooth wheel with VR sensor on top, which outputs second signal to ECU (green, white-black).

Can I use this with MS? How do I setup this in MegaTune?
It is like 4-1 wheel on cam, which would translate to 2-0.5wheel to crank, which does not make sense However it seems to provide enough information to calculate the moment when spark is needed. There should be a spark event on each trigger from bottom wheel, and the top wheel could be used to find the Cyl1 TDC.

Any suggestions?

[Minorobsession]

I am assuming that the IAC on a 4age blacktop is the same as a silvertop, dont over complicate the circuit, use the diagram for the bosch 3 wire and experiment with the resistor and the frequency. The lower the value of resitance the more the valve is pulled closed and a higher DC required to open it and visa versa.

I cant remember the resistor that I used, use the highest value that still gives you a slow idle, next time I have the covers off the A pillar I will measure it, the frequency is 200 and the DC sits around 40-45% for version 029q.

Sure the other circuits are more eligant but what is the easiest to implement and manintain?

Remember to uprate the Q20 tranistor driving it.

[Minorobsession]

It was an 82ohms resistor.