is microsquirt for me?

[dusterbd13]

So, I figured that this is the best place to ask.

I'm running a small block mopar on a gm tpi based efi swap. All electronic and sensors from a 91 corvette. I can't seem to get it reliably running, and that's due to software.

I know megasquirt has an auto tuning feature, and that many people are having great success with it.

All I want is drivability and reliability. The megasquirt programming looks much simpler as well than modifying the bin and burning proms.

The car is already set up for bank to bank injection, with an iat, iac, map, tps, and cps. Single e coil, gm ignition control module, msd box, and glowshift wideband.

Is microsquirt for me?
Do I need to order anything else besides the microsquirt unit and harness?
Does it have a check engine light feature?
Will it control my electric fans and fuel pump relay?

What questions am I not asking?

[ewflyer]

Most car guys go with one of the other full-featured ECUs like the Megasquirt 3. Right now you say all you want is functionality, but I guarantee as soon as you start having some success with your project you'll want to do more (more than the Microsquirt can do). I'm not talking the Microsquirt down, I have two motorcycles running Microsquirt ECUs. I love the Microsquirt.

[slow_hemi6]

Microsquirt does not have a check engine light. Have to get MS3 for that one.

[dusterbd13]

Most car guys go with one of the other full-featured ECUs like the Megasquirt 3. Right now you say all you want is functionality, but I guarantee as soon as you start having some success with your project you'll want to do more (more than the Microsquirt can do). I'm not talking the Microsquirt down, I have two motorcycles running Microsquirt ECUs. I love the Microsquirt.

What could I possibly want to do that microsquirt doesn't?

I guess I am just wondering why I should look at the ms3. If I can get the 91 corvette ecm to work, I see nothing it does that microsquirt doesn't other than the check engine light.

[DaveEFI]

Most car guys go with one of the other full-featured ECUs like the Megasquirt 3. Right now you say all you want is functionality, but I guarantee as soon as you start having some success with your project you'll want to do more (more than the Microsquirt can do). I'm not talking the Microsquirt down, I have two motorcycles running Microsquirt ECUs. I love the Microsquirt.

What could I possibly want to do that microsquirt doesn't?

I guess I am just wondering why I should look at the ms3. If I can get the 91 corvette ecm to work, I see nothing it does that microsquirt doesn't other than the check engine light.

Unless you are tight for space (unlikely in a car) there are no advantages in a MicroSquirt over the standard size ones. But plenty of disadvantages.

[Matt Cramer]

So, I figured that this is the best place to ask.

I'm running a small block mopar on a gm tpi based efi swap. All electronic and sensors from a 91 corvette. I can't seem to get it reliably running, and that's due to software.

I know megasquirt has an auto tuning feature, and that many people are having great success with it.

All I want is drivability and reliability. The megasquirt programming looks much simpler as well than modifying the bin and burning proms.

The main drawback I can see of a MicroSquirt here is that it does not have a stepper IAC output built in; an MS2 would run the stepper valve.

Does it have a check engine light feature?

If you want that, you'll want a MS3.

Will it control my electric fans and fuel pump relay?

Yes.

[AndyB]

I've used a Microsquirt on a Rover V8 for the last 3 years and I feel like I've used it up to its limit now. The big short commings are only 2 fuel outputs and 1 lambda input. That means firing 4 injectors at once which is not great for fuel rail pressure or injector timing. And my wideband is located in the right hand manifold so I have to assume the left hand side is the same.

Like yourself when I checked the specs it did all I wanted but since then I've added knock control and I wanted more inputs for oil temp & pressure and output so I'm using a add on Tiny IOx and a knocktek. I'm now looking at a MS3 Pro so I can do at least semi sequential but ideally fully sequentail fueling. It will also mean I can remove the knocktek and TinyIOx. I've recently converted from EDIS8 to using logic coils by repurposing the WLED and ALED outputs to run wasted spark on a V8 which is impressive given what the ECU was actaully designed for. So I am a fan of the Microsquirt but I would recommend an MS3.

[dusterbd13]

So I'm back on this thing again. Is there a way to make microsquirt control a stepper iac?


Does it have vss output for my speedometer?

And I'm assuming that is has grounds to control fan relays and a fuel pump relay, correct?

[dontz125]

So I'm back on this thing again. Is there a way to make microsquirt control a stepper iac?

Why yes - yes, there is! I am expecting a shipment of PWM-to-Stepper controllers next week; connect the input wire of the controller to the FIdle pin of the uS, and set up TS as though it were a PWM idle valve. US$60 + 15 for the postman.

Does it have vss output for my speedometer?

No. Depending on how the VSS signal is generated, and how the speedo is driven, I may be able to set you up with a speedo corrector.

And I'm assuming that is has grounds to control fan relays and a fuel pump relay, correct?

Yes. The pump relay driver is dedicated; there are two more relay drivers that can be used for various purposes, including switching a fan on and off. Just watch you don't run out of I/O pins for your other needs.

[jsmcortina]

There's also a Microsquirt stepper adapter from EFI Source.

James

[dusterbd13]

So, if I'm understanding this correctly, the microsquirt will be able to do almost everything that the gm computer is supposed to do in my application with the addition of the stepper motor conversion. Right?

I'm assuming Auto tune requires a wideband. Will my glowshift be compatible?

I have a standard vss in my treece tko600, and a speedhut programmable speedo.

I have dual fans I would like to control.

I have an in tank electric fuel pump is would like the computer to control.

Batch fire, and hei distributor.

Looking for drivability and durability and ease of setup/tuning. I can wire just about anything, so no concerns about that.

I'll link the build thread so you guys can see exactly what we are working with. I'm just wanting to finally drive the d*** car again.

[dusterbd13]

http://www.pro-touring.com/threads/7175 ... g-makeover

Build thread that is up to date.

[dontz125]

Yes, Autotune / VEAL needs a WB sensor. If your particular Glowshift gauge has a 0-5v linear output, then yes - it can be used as your WB controller.

I don't know enough about your particular VSS and programmable speedo to comment intelligently; if the speedo can read the VSS pulses directly, then you're set. If the VSS is a VR and the speedo can't read VR, you will need a filter circuit; it should be fairly simple, as true zero-crossing isn't needed.

Do you want to control the fans separately (coming on at different temperatures) or together? Either could be done, but the first would need two output channels. In either case, you'd want to drive relays vs driving the fans directly.

In-tank or external shouldn't matter; the fuel pump would be powered by a relay, which would be activated by the (dedicated) fuel pump relay driver output.

Batch fire and HEI distributor is entirely do-able.

Either stepper driver will work. Mine has less wiring and takes up fewer uS pins, but is slightly less capable for certain installations ("Always on" control only, fewer options for Min # steps, etc). James' design (through EFI Source) is capable of fully controlling the IACV, but requires more pins, 5v as well as 12v power, etc.

[dusterbd13]

I'd like to do independent control, as well as turn them on with the air conditioning. I can do that via a Trina Ryan switch though. Not a requirement for independent control though. The vss isn't required by microsquirt? It will drove my speedometer fine, I'm worried about splitting the signal, as the gm ecm doesn't like that.

When you are talking about the pins on the stepper motor control, just what do you mean? As in, with my requirements, will I run out of pins?

[dontz125]

The uS actually has no use for the VSS; there are no functions using it.


Possible pinout, HEI7 ignition, 2 fuel channels, 2 fans, stepper IACV:

Dedicated (no options):
FP - Fuel pump relay
INJ1, INJ2, fuel out
IAT, CLT, MAP, TPS, VRef
O2 - WBO2 signal

Not used:
VR2+, VR2-, VR1+

Option / configure:
IGNOUT1, HEI EST
IGNOUT2, HEI B
VR-, HEI R
ALED - Fans (or Fan1)
WLED - Open (or Fan2) (or Stepper)
FIdle - Stepper
FLEX - Open (or AC Idle Up)
SpareADC - Open (or Stepper)
SpareADC2 - Open (or Stepper)
TACHO - Open

The Spare ADC pins can be used for things like Constant Baro correction (handy if you're going up and down BIG hills), 2nd WBO2 (if you're concerned that the left and right banks are flowing differently), or knock input. Each of these requires a specific sensor. CBaro cannot use the MAP sensor. 2nd WBO2 or Knock require a particular controller between the uS and the sensor.

The EFI Source PWM Stepper controller uses the following combination of uS pins, and uses the 'Stepper Valve (4 or 6 wires)' settings in TunerStudio:
[SpareADC2 + Fidle + SpareADC] -or- [WLED + Fidle + SpareADC] -or- [None + Fidle + SpareADC]
It requires separate 12v and 5v (VRef or other) power inputs.

My controller uses the FIdle pin, and uses the 'PWM Valve (2 or 3 Wires)' settings in TS. It has an onboard power supply for the 5v components. Various settings are selected using DIP switches in the housing.

Summing up the stepper controllers - the EFI Source version gives you more options and can be set in software, but needs more pins and wiring. Mine has fewer adjustments, but leaves more pins available for other functions.

[billr]

Duster, you indicated you can wire anything; does that mean you are also comfy with soldering? If so, the MS3 kit is only $90 or so more than the Micro. I think that is rather trivial compared to the overall scope of projects like this, so always advise MS3 as a starting point. Just recently I got caught on a handy function that MS3 can do and MS2 can't (I'm assuming Micro is same as MS2 in this regard); don't put limits on your system right at the start for only $90! Actually, the price delta may be even less, since you won't have as much need for "add-on" boards.

[dontz125]

I'm assuming Micro is same as MS2 in this regard

Aside from the hardware limitation of 2+2 channels and stepper control, I believe the MS2 and uS firmware is basically identical.

Back to your point of wiring vs soldering - unless the new MS3 owner is prepared to DIY a fair bit, he / she / it will likely be buying a MS3X card to take advantage of all those neat capabilities, so the price delta is quite possibly another $105 higher; more, if the individual goes with the prebuilt board. As you say, it comes down to the builder's confidence - a lot of V3.0 kits are / have been sold, but a lot of uS and V3.57 units are also going out the door.

[dusterbd13]

Unfortunately, my hands aren't steady enough to solder a circuit board. And price is a considerable thing here, as I've pissed so much away on the gm stuff. I really like the price delta of the microsquirt, but with the addition of the stepper motor control, it approaches closely to megasquirt 2 and harness from diyautotune.

But it's looking like the microsquirt will do it all.

How does it do with deceleration with no vss? On the gm stuff, it'll stall almost every time if you don't blip the throttle.

[dontz125]

Again, it doesn't care about VSS; all it cares about is the RPM and the change in RPM, and the change in TPS. There are different settings that allow you to dial in the part-throttle, idle, and overrun characteristics. Stalling because you didn't blip the throttle while slowing down might happen the first time or three you take it out for a tuning run, but it should get pretty rare, pretty quick.

[krisr]

What about a preassembled ms2 which is as mentioned virtually an uS, but you're not locked out of ms3 upgrade path. I personally did this and did not regret it one bit. My car is now multicoil sequential fuel, ms3 drives all my dash gauges etc... it was once a simple v8 running batch