Megasquirt users thread to discuss all things Squirty

[oldcorollas]

if you need any help, gimme a buzz

[dnegative]

Cheers mate

Hopefully its smooth sailing though

[oldcorollas]

well it does say plug and play
the tuning is pretty straightforward.. as long as you know where you are trying to aim for

[jabbatron]

..........

[dnegative]

Looks like my ECU will arrive next week, should give me enough time to sort out the minor wiring changes needed;
The MS2PNP is designed for a AFM 4AGE and mine is a factory MAP sensored model, essentially the same shit but there are a few pin out differences on the plugs.

http://www.club4ag.com/faq_and_tech_...GE%2088-89.htm
vs
http://www.club4ag.com/faq_and_tech_...4A-GE%20NA.htm

As far as I can really tell they all have the same shit but with everything in different spots (minus MAP/AFM on the respective ECU) so I'm going to have to swap the pins around on the plug which is pretty straight forward.
Anyone have any thoughts on the matter?

[knightrous]

I don't think it's going to be as plug n play as you think, especially since your plugging it onto a motor it's not setup for. Your going to run in to a couple of hitches because the MAP 4AGE Bigport runs the ESA ignition system, not the VAST ignition like on the AFM 4AGE Bigport. There is a white paper here: http://www.autoshop101.com/forms/h23.pdf that explains how both VAST and ESA work and their differences.

Essentially, VAST has the dizzy wired into the ignitor and it interfaces with the ECU while ESA interfaces the dizzy directly to the ECU.
VAST Diagram below for visualisation:


You might find that you spend more time modifying the MSPNP into an expensive DIYPNP.

[dnegative]

Hm, I thought only the smallport used the VAST ignition

[knightrous]

In other news, bought myself a new Innovate MTX-L wideband and spent the today doing around 150km tuning the tables to be better. However, after playing with VEAL and tuning bits and pieces, it still wasn't running right and things were a bit off in a couple of places and fuel economy was pretty shit(9.5KM/L). So I looked back through 150km of logs and found that a lot of the fuel economy is because even at light cruising loads I was still getting readings of 90-94KPA despite the throttle varying from 1% - 35% which constantly pushes VEAL and ECO to aim for 12.5:1 AFR, which is a bit rich to be setting on at 100KM/H along the highway . So decided to give Alpha N a shot, within 30mins and 15-20km, I now have a tune that is much more responsive, fuel economy looks good as I'm cruising (able to hit AFR's of 14.5 - 16) and it still pulls hard to 8000RPM. Looking forward to spending the rest of the week doing a few hundred km perfecting the maps a bit more to make it as drivable as possible

Random stuf: Getting about a 1 AFR difference between the MTX-L guage and the TunerStudio reading, I'm currently attributing this to the 6ft of wire carrying the analogue signal between them, the voltage drop over 6ft is probably enough to swing the AFR out that much. I'm going to hit up the MSExtra devs about running serial from the MTX-L into the DIYPNP and then using a small PCB with a MAX232 and ATMega8 chip to convert serial to ADC then spit it out to the O2 pin, hopefully it will make the signal more accurate since analog can be affected by a large range of crap over 6ft of wire. I noticed the Adaptronic ECU's have a dedicated serial port for widebands, so this might be why they feature such a setup as well.

[knightrous]

Hm, I thought only the smallport used the VAST ignition

Smallport is ESA along with the 20V's.
VAST is pretty cool in the fact that you can actually drive the car without an ECU connected, as long as you can provide fuel (carby or start ya bastard ) it will detect the motor rotation and provide 10' spark advance. If you then generate a 5V square wave signal you can make it advance the timing
VAST is pretty much an EDIS4 system for use with a single coil and also inherits it's shit ability not to allow spark retard / cut.

To get your setup working (and assuming that the MSPNP is just a DIYPNP with all the crap done for you internally, and not a custom PCB) you will most likely need to rewire the NE pin to VR+, G- to VR- and G2 (or G1) to VR2. You can then either use the stock igniter to drive the coil using the IGN1 or use a BIP373 transistor to drive the coil directly. To get the G2/G1 to detect properly on the VR2 input, you might need to install a 51K resistor in R20.

Randomly, do you know the trigger pattern in your dizzy, is a 4 tooth NE wheel with 1 tooth G wheel, or a 24 tooth NE wheel with a 4 tooth G wheel, or a 24 tooth NE wheel with a 1 tooth G wheel?

[thechuckster]

So I looked back through 150km of logs and found that a lot of the fuel economy is because even at light cruising loads I was still getting readings of 90-94KPA despite the throttle varying from 1% - 35%

That's a pretty high MAP reading for cruise? or just a feature of your ITBs?

btw, what kind of analog signal have you configured the MTX-L wideband to output to send to the ECU (0-1 or 0-5v)?

[knightrous]

That's a pretty high MAP reading for cruise? or just a feature of your ITBs?

Result of the ITB's, never had this issue with my old bigport . I'll eventually get into learning how to setup the ITB mode correctly and have the best of both SD and AN, but for now, I'm happy with AN.

btw, what kind of analog signal have you configured the MTX-L wideband to output to send to the ECU (0-1 or 0-5v)?

I set it up as per the Innovate manual, which is 0v = 7.35AFR and 5v = 22.39AFR. Setup in the AFR tables as a custom wideband as there isn't a predefined one for the MTX-L.

[thechuckster]

I think the MS manuals do suggest that AN being a better solution for aggressively-camed ITB engines - tho some folks have had success with mixing map signals from each port.

I do wonder whether having such a high MAP value results in lower air-speed in the ports than you'd find in a single TB engines (like my 3SGE)? and whether that results in fuel atomisation issues at those same MAP values, particularly when the engines isn't running very fast.

However, if AN works for you, then awesome (tho for some reason your skid pics are not loading).


WRT the Innovate, I think a number of folks on the MSextra forums have noted discrepancies between ECU data and 2nd-channel output from WB controllers. In my old setup I only ever used the 2nd-output to drive a LED bar display on the steer column and never bothered to log data from the controller.

Most people using the first-gen Innovate controllers were pre-occupied with earthing issues to compare log data from the ECu and controller.

I reckon the ideal solution is a WB controller with a CANBUS interface. Would save having to do any A/D conversion at all, tho it then demands that the ECU support CANBUS. MS3?

[dnegative]

To get your setup working (and assuming that the MSPNP is just a DIYPNP with all the crap done for you internally, and not a custom PCB) you will most likely need to rewire the NE pin to VR+, G- to VR- and G2 (or G1) to VR2. You can then either use the stock igniter to drive the coil using the IGN1 or use a BIP373 transistor to drive the coil directly. To get the G2/G1 to detect properly on the VR2 input, you might need to install a 51K resistor in R20.

This was sort of along the lines of what I was anticipating, re-pin the plug to give the box of sunshine what it needs in the right places.
Documentation is a bit thin for how exactly it is setup but if its going to be a bit of a headache I'll spend the $200 and buy a ADM/USDM AFM harness, coil and ignitor and swap the loom over. Everything else (injector plugs might be different, both MAP/AFM use low impedance w resistor pack) plugs up and in.

[knightrous]

Hopefully it is just a pre-configured / assembled DIYPNP, in which you can just crack the lid and change a few of the jumper wires instead of having to re pin the loom. Anyway, when you get it, open the lid and take some photos, keen to see 'the gutz'

[dnegative]

Yeah will do

I might be throwing this on the backburner for a couple of weeks, I want to get my extractors and exhaust done. I'll weld in the new bung for the wideband this weekend, send them off for ceramic coating and I'll buy a new muffler, flex and a bunch of bends and start welding. I'll spend the time reading up on how everything works in the meantime, I know shitloads about diesel but only just enough to get me by about spark based EFI - I understand the concepts but its the finer details that I need to brush up on.

Still, looking forward to getting it going. Even if it poses a few problems, god forbid I've been fucking bored of late.