Megasquirt Newbie Questions - All the really dumb ones you were afraid to ask!

Mines a bill shurvington one refined by Toyotec lol

 

Binned diagram !

 

That diagram is wrong mainly as the rpm trigger does not go to the ECU but to the TCI unit. This will result in a no start as the ECU does not know what engine speed to perform calculations for fuel and ignition angle.
Such a diagram should be junked as it will be the cause of many issues. This is why I recommend the RSA diagram as the MS unit is built to match this.

 

Binned it

 

Here's a dumb question for you guys: The only sensors that i need for my 16v are 1)Inlet air temp 2) coolant temp and 3)MAP or do i need anything else for the MS to run? I'll use the stock inlet manifold and not itbs so i thought is better to use MAP instead of TPS?

Cheers

 

+ hall sensor.

 

Thanks Trev
Yep i forgot to mention that.1 bar MAP sensor is enough for N/A 16v?
Also,any recommendations for where to source cheap inlet air temp sensor and MAP sensor both with their plugs?

 

I've been looking at the track car today, for the first time in a few weeks, and got a few more bits done. I'm still confused around the ignition system though.

Brooky's diagram above looks closest to the setup in my car. I looked at the version on the 8v thread, but my car doesn't have the same setup mentioned here:

I don't have the 5 pin connector, as the 8v kjet cars don't have an ECU.

I was wondering if it would work if I added a duplicate RPM trigger to the ECU? The TCI unit to hall sender wiring mentioned there is as per factory.

 

Mike

That diagram came from a Rocco 8v megasquirt conversion on the VWVortex in the US so i think it should be right for you.

Here's another Rocco 16v MS Conversion

http://forums.vwvortex.com/showthread.php?3734966-Megasquirt-in-my-16v./page10

 

Cheers Brooky - as Toyotec said above, it seems to be missing the RPM signal to the ECU, so needs a bit of tweaking at least.

EDIT: Looking at it again, it seems to be using the No7 terminal on the TCI unit for that - it's unused on the standard 8v Kjet setup.... interesting... Is that a spare terminal to send an RPM signal I wonder?

 

No no. 7 isn't used on mine.

 

As I said earlier, use the config for a digifant vehicle, if using single coil.
Also use the RSA diagram.
Hall signal should go direct to MS not TCI-h.

 

Hi Eddie

Thanks for the feedback.

I don't really understand how to integrate that setup into my loom - I don't have the 5 pin plug. I'll see if I can catch you on the phone later in the week. Maybe I'll understand better with some wise words over the phone.

 

Sorry to butt in Mike, but I'm in the process of connecting up the distributor to the TCI-h unit in my Kjet car at the moment, and I'm having similar problems.

I've been trying to find out how the standard VW distributor Hall sensor works, ie: whether it sits at +ive V then drops to earth when the dizzy window passes it, or vice versa, which determines which ECU pin to connect it to. My ECU is a microsquirt but basically the same as megasquirt 2 I believe.

As far as wiring it to the TCI-h unit goes, it says to take Hall/VR signal to the appropriate input on the ECU, then connect the ignition output from the ECU to the original Hall connection on the TCI-h unit.

I've just had to swap some jumpers over inside it, so that this ignition output is configured to run the TCI-h unit, rather than direct-driving a coil.

 

That's kind of my problem too. Ideally I'd like to understand what it's all doing, which will give me a better chance of diagnosising any future problems.

Eddie built my ECU for the setup I've got, so that won't be the problem. It's just my understanding of how to hook it up. I don't have all the right connectors to copy the digifant method. That VintageWaterCooled diagram implies you can take the signal from the unused No. 7 connector on the TCI unit, but I'm clueless.

 

I think eddie needs a technical secretary.

 

The way I understand it so far, at present the Hall signal from my mech. advance dizzy goes to the TCI-h, where it tells the TCI-h when to fire the coil. How much spark advance is down to the mechanical parts inside the dizzy.

With a fixed dizzy the timing of the Hall signal is non-variable, so the signal gets sent to the ECU, which works out the advance, then that tells the TCI-h when to fire the coil. So the ECU is basically intercepting the original Hall signal, doing some maths, then passing it on to the TCI- unit, on the original dizzy signal wire. I hope I've got that right.

edit: this is the picture I'm working from:

 

Yea. I think that's what happens with a dizzy triggered system. The megasquirt doesn't work it out though. You program it to fire when you want.

 

Groovy

So presumably, the ignition input on the ECU must be configured to recognise the Hall signal from the dizzy, (going high/going low etc), and the ignition output from the ECU must be configured to match the original dizzy Hall signal, so the TCI-h recognises it?

 

not sure how microsqiirt work but it should output a signal of high/low also at a certain voltage like 5v.

If you read the ms extra ignition manual it tells you. If you are using a 4 window dizzy, you need to use mans mode an. Set up a locked dizzy using a timing light. Procedure is in manual