Megasquirt owners thread

[Cus]

Mine's 383Hz - "seems to work ok" ... I've not fiddled with the frequency settings though, I can command different idle valve settings in TS and get matching results on the engine, so didn't bother

The lack of vTPS might be getting you into CL Idle, cruising around town will look a great deal like a high-RPM idle without a vTPS input. (Low kPa, steady engine speed) - which TPS do you have? I modified a VL crumbledore one, and until it was on the car and calibrated, it looked very much like it was faulty.

[StanTheMan]

Currently I have the stock NA 6 one. Dan mentioned TPS.....does PID Idle control require a vTPS? Its currently always off in the logs
which certainly satisfies one requirement for it coming on. But the minimum RPM is 1500. when it did come on it was over 2000 rpm.

I'll check it out

[Cus]

There is an adjustment for the stock tps/ecu combo (put a continuity tester on the TPS plug, and rotate it on the mount, I'll find the details when I get home next week if you want) so you should be able to get at least closed and open, and maybe WOT ... Not sure how the ms will deal with that information though.

On the flip-side, if your CL Idle is setup correctly, dropping into CL Idle Mode at cruise wont break anything, it's just "not correct", but you should still be crusing along happily.

[Red_Bullet]

[quote="StanTheMan"]By the way.

what are we all using for the Idle Valve frequency? in particular for the NA6's

I should find the Thread on Miata Turbo where they recon they confirmed 170 MHz.

the basemap on megasquirt for the NA6 came with some setting close to 400

found it
http://www.miataturbo.net/megasquirt-18 ... ncy-48120//quote]

I'm using 306 Hz, I set this up on day 1 when I fitted the MS3 nearly two years ago, experimented with a few settings then but never revisited it. BTW it's an NA8.

[StanTheMan]

When I calibrated the TPS it doesn't give any volts. So it's probably toast?

[Red_Bullet]

When I calibrated the TPS it doesn't give any volts. So it's probably toast?

You should have 5 volts going to the TPS and signal ground. The Tps output (input to ECU) should vary between 0-5v depending on throttle position.Throttle closed closed to 0 volts, 1/3 throttle 1.67 volts, 50% throttle 2.5 volts, 2/3 throttle 3.3 volts, WOT close to 5 volts. You can measure that with a multimetre set to DC volts. That should confirm if you TPS is working. Metre black lead to signal ground and red lead attached to TPS output.

[StanTheMan]

I have 2 TPS both stock ones. Did you read the TPS was non variable? My understanding is the non variable just Hand off/0n
I'll try that.if that doesn't work I'll try the other one. I did swap them over. When I put the Megasquirt in for a trial fit. I don't know which was the original
There was an issue with one of them when reverting back to stock later that day. One could be toast.but I will check

I did have a 3 series vTPS a few years ago when I had the Adaptronic. Maybe I'll have another good look around for that.

Thank you.

[Cus]

When I calibrated the TPS it doesn't give any volts. So it's probably toast?

Quite possibly! I'll look in the service manual for the specs for it when I get home next week, at the very least your can turf the faulty one(s) so they're out of your way, or sell them to someone doing a concourse resto if they work

[NitroDann]

I'm currently using MAPdot. I thought I had a Variable TPS. But I don't.

Well thats probably why.

It should be disconnected.

Dann

[StanTheMan]

Oh right.as in unplugged and or totally taken off?

[Red_Bullet]

I have 2 TPS both stock ones. Did you read the TPS was non variable? My understanding is the non variable just Hand off/0n
I'll try that.if that doesn't work I'll try the other one. I did swap them over. When I put the Megasquirt in for a trial fit. I don't know which was the original
There was an issue with one of them when reverting back to stock later that day. One could be toast.but I will check

I did have a 3 series vTPS a few years ago when I had the Adaptronic. Maybe I'll have another good look around for that.

Thank you.

Nope, I didn't read it was non variable. I'm dumbfounded as to what purpose a non variable TPS might perform and I've never heard of it, but that doesn't mean it doesn't exist.. GMF. Care to elaborate what it's for then? Is it just a switch to indicate to the stock ECU that the throttle is closed?

[jordan.k]

Nope, I didn't read it was non variable. I'm dumbfounded as to what purpose a non variable TPS might perform and I've never heard of it, but that doesn't mean it doesn't exist.. GMF. Care to elaborate what it's for then? Is it just a switch to indicate to the stock ECU that the throttle is closed?

Stock na6 TPS had to little prongs that touch when the throttle plate is on WOT, gives a WOT signal to ECU, this is basically useless for aftermarket ecu's as you can't do much with this signal as the only thing you know is if it's at WOT or not.

You can't tune for tps with the stock na6 tps you need one with a variable component. It's just a potentiometer that varies resistance at different positions of throttle and gives this signal to the ECU (with minor wiring mods). I had success using a used rb30 vTPS which looks OEM. When you learn the vTPS it the 0 and 100% adc readings should have a fair difference between them to know it's right, i.e 0% 500, 100% 1500 etc. not both around 500 adc.

TL;DR stock na6 tps is junk

[Red_Bullet]

Good to know, I've only played with an NA8.

[StanTheMan]

If I take it off....that would be extra added lightness....whoooo

turns out Neither TPS gives me any reading.

[Red_Bullet]

Well, If it's possible to fit a variable TPS in it's place there might be certain benefits with that. The first one that comes to mind is being able to set up TPSdot controlled Acceleration enrichment.