have you tried grounding the vr- to the ms2 ground?
dont worry about the factory ecu biasing the sensor, thats only for the ecu to detect faults with the VR.
Ive installed heaps piggybacking the factory ecu to reatin the auto and not had any sync issues. both pots fully CCW and then around one to one and a half turn CW

66 Coupe, all the same i'd rather not short out the 2.5V. I've decided to dedicate the VR sensor to the megasquirt, and run the VRoutinv back to the VR+ of the stock ecu. From what I can gather this should work perfectly.

Anyway, my laptop hard drive has been on the fritz so instead of wiring up my falcon I got to install a new hard drive and ghost everything back over (yay ). So no progress at the moment so now the earliest I can get to it is Wednesday (after work).

Thanks, Thomas.

thomas, take my advice and ground the stock vr- wire to the ms2 ground.
The stock ecu uses a differential input, dont worry about the '2.5v' it is only a weak bias and is only used for the std ecu to deterime an open circuit on the VR. Shorting it to ground wont blow anything up.

if you were to use the vr out inv from the ms2 to feed the stock ecu, what is the stock ecu going to reference that signal to, ie you will feed that into vr+, but what are you going to do with vr-? you will need to ground it to the ms2 anyway for that to work.....

also the stock vr wires are fine, they work fine with the std ecu so dont worry about changing them to shielded etc.

Ok, i'll take your word for it. I'll run a twisted pair from the stock ecu VR- and VR+ to the megasquirt give that a go - as I said this will have to wait until Wednesday unfortunately.

Thanks, Thomas.

So I was lazy and didn't update yesterday . I have rerun the VR wiring using a shielded cable (from the stock ecu to the megasquirt, it remains twisted pair from the stock ecu to the sensor). Decided to try 66 Coupe's advice and what do you know, perfect sync (even cranking) on my first attempt (thanks, 66 Coupe ). VERY happy at that, now I can start to tune my cranking pulsewidths properly.

Anyway a few pictures, first I took a pic with the cover off the megasquirt, purely because I don't think i've done so earlier... The transistor attached to the top half of the case (with red wiring) is my idle transistor - a TIP122 exactly per the documentation. The transistors attached to the megasquirt heatsink bar with yellow and orange (ran out of yellow ) wiring are the BIP373 ignition coil drivers (3 in total, one is hidden under the MS3 card). Modifications to come: Tacho output, VSS input and an output for the Thermofans. I want to get a reasonable amount of functionality out of the mainboard, so when I come to build my addon board I will have to add less circuitry.



Anyway, I thought it prudent to also include a photo of my work area also known as s**t everywhere . Whilst at this stage I also reran the TPS Voltage reference signal and ground to the megasquirt rather than relying directly on the stock ecu... This has cleaned up my signal enormously and i'm now quite happy with it.



Anyway, not much else to report so i'll report back when theres more.

Thanks, Thomas.

Edit: I know pics are broken, filezilla is having a bit of a spaz - will fix them when I get a chance.

all good

one more tip, while the cover is off, use some hot glue if you can get hold of a hot glue gun, or some non conductive silicon (RTV silicon is conductive) and put glue around the wires and legs of the IGBT's and Tip122, reason being with vibration the wires can end up fracturing the legs off the transistors, the glue helps stop movement.

Its already back together (for the time being) but once I add some more circuits I may take your advice, however its currently velcroed to the carpet under the passenger seat so I don't think vibration will be a huge issue (incidentally, au falcon carpet makes for a REALLY good female velcro connection... its actually quite difficult to move/remove the ecu).

Plan now is to get as many of the settings dialed in as possible, before altering the ecu or adding more functionality. Hopefully I can start the LPG side of things in the next month or so (my b'day is quite soon, so i'll get everyone to pitch in for some LPG injectors as a present ).

Thanks, Thomas.

66 coupe, I tried your spark map from here, but it started to knock quite noticeably (even after take 2 degrees out - will try 5 in the morning and see what that does...) I'm just curious as to what engine you developed this on, was it a VCT?

No other updates as yet , just got 4 new tyres :O and I think I will need to replace all my bushings with polyurethane soon - rubber ones are cracking and generally s**t (+ i'm getting a knocking noise in the rear). I'm starting to look at the LPG side of things, and i'm thinking of altering my plans slightly - to drop in a BA NA engine (cheap as chips - and from what I can gather will not require engineering) and then develop a turbo setup for it later ("develop" means gather parts from an XR6 Turbo ).

Thanks, Thomas.

Sorry for the lack of updates, but that's due to not much happening... I've finally got the cranking settings where I want them (but need to work on the afterstart and warmup enrichments - after I get the VE table properly tuned). Reduced cranking advance to 15 degrees - resulting in MUCH smoother and more consistent starts (it was previously 20 degrees).

In the meantime, i've been looking up some LPG equipment, got some quotes of Tickford_6, but after looking around online I think I may order from the UK from: here. I'm looking to buy two of these and this. Cheap enough + will give me plenty of room to play around with power in the future. I have an email from a forum member here (can't remember exactly who) who has the Magic Jet Injectors working with Megasquirt.

Uni is being a bit of a b**ch at the moment, so updates will be a little slow until I get on top of things.

Thanks, Thomas.

Just an update, haven't given up - just been awaiting funds to proceed with the SVI side of things. I've designed most of the circuitry so should be ready to go.

Will keep you all updated - hopefully not too much longer.

Hey mate, I am turboing my AU2 and was looking for a system that let the auto run from the standard ECU. I think this is the go. You seem to have had minimal trouble. I will be watching with great interest and I will start a thread on my build.

Good luck!

Thanks for the kind words, I wouldn't say i've had *minimal* trouble (i'm still not 100% happy) but it has definately been worthwhile. Anyway, i've just got a new job so i'm probably about to go from lots of time but no money to lots of money but no time, but we'll see - have a few other side projects going on that have been taking up time but I haven't forgotten about the megasquirt .

The thing that has really been setting me back of late is injector dead times - its gotten to a point where i'm thinking i'll build a test rig and just do the test that way (at least it'll be reliable). I can't bring myself to put in the SVI gear until i'm pretty happy with the petrol side of things.

Thanks, Thomas.

Just as an update, I have (hopefully) fixed the slight oil leak I had. Spent 3 days basically resealing the timing cover - didn't take pictures partially because I was covered in grease/mud/s**t and mostly because I was getting p****d.

SVI coming soon!!!

Really interesting read, looking forward to seeing more updates as i'm considering this for my XG which will be getting a BA 4 litre but have no ecu so i'm hoping that the ms3 will control VCT/VVT twin cam angle sensors sequential spark and injectors.
Keep up the good work.
Cheers, laurie

The MS3 can do up to 4 VVT using the newest alpha releases - I will be experimenting with them in the future (by the time I get a DOHC or a XR6 Turbo engine the alpha release will probably be finalised). Anyway, good news - once a cheque clears I can order (finally) the LPG equipment! So hopefully I won't keep you too much longer .