Megasquirt won't communicate!

Thu May 29, 2008 3:40 pm

I've got an m20 with ITB's and megasquirt 2 with v3 board. I've had the ECU running on the simulator months ago but now it won't communicate with the PC. Anyone got any ideas?

Thu May 29, 2008 6:08 pm

maybe the wrong firm ware to read the ms on ur computer?

Thu May 29, 2008 7:23 pm

USB to Serial adapter in use ?????

DB9 straight thru cable or null modem ?? null cables have pins 2 and 3(iirc) reversed male/female and you'll get nowhere in that case.

Check comms settings etc etc ??????

and does it still work on the Stim ?? but not the car ?????????

You should add your location to your profile too dude, may elicit a local zoner that could help

Sun Jun 15, 2008 10:29 pm

Cheers, yeah running the ms with a straight through serial 9 cable, tried a serial to usb. Nothing from either.

Fri Jun 27, 2008 12:33 am

Thought I'd better update this thread. Got comms now, just no crank speed signal (using VR sensor). Think the comms problem was down to a bad joint at the serial 9. Think the crank sensor is possibily too close to the trigger wheel; didn't think this was possible but apparently so. I'll get a look this weekend.

Fri Jun 27, 2008 11:41 am

The VR has a few wires, yellow, black and screen wire IIRC, you want it backwards to what you would think you need.

There's also another identical set of wires in that loom under the dash.

I know this as I got the wrong ones first time myself!

Keep us updated, we're here to help!

MS community on the zone is growing by the day

Fozz.

Sun Jun 29, 2008 12:29 am

How have you got the VR wired up? Are you using a standard MS loom, or have you connected it all up to he stock motronic ECU plug?

Sat Jul 05, 2008 12:10 am

I'm using a blank 12' loom from diyautotune.com, I stripped down a standard loom to just the relays, oil level/pressure and coolant (for temp gauge) along with a few others and used the blank loom for all MS in and out whilst retaining the c101 so it plugs straight into the car.
Took the standard trigger wheel and milled it down to make it 36-1 as I'm using EDIS, now the VR sensor is too short so I'm using a longer Ford unit I had lying around.

Sat Jul 05, 2008 12:16 am

You milled the 60-2 wheel to a 36-1? Extracted a few teeth?

Sat Jul 05, 2008 12:27 am

Last weekend I re-shimmed the VR sensor to 1mm (was 0.45, megamanual says 0.75 - 1.5mm) but still nothing. Recently been having problems with the MS stimulator (mains power supply only supplying 150ma instead of required 300-500!). A decent transformer should sort comms problems.

Today I realised the MS needs the Hall sensor circuit to run with the EDIS as it converts an anologue sine wave from a VR, to a digital square wave (like from a hall sensor).
Luckily I installed both circuits when I built the MS so I simply changed the jumpers over, I'll give it a whirl tomorow!

BTW, if this all seems a little drawn out it's because my laptop has no serial 9 port and my serial 9 - USB don't work! so I've been dragging the PC out of me mams house to use on the driveway whenever I get a spare minute.

Thanks for your input, photos coming soon!

Sat Jul 05, 2008 12:30 am

FlappySocks wrote:You milled the 60-2 wheel to a 36-1? Extracted a few teeth?

LOL Yeah, I think there's a decoder now to use any wheel but not sure if EDIS likes this. The trigger wheels been sat around longer than the ECU.

Sat Jul 05, 2008 12:37 am

This I have to see. Can't wait for the pics.

I guess the teeth are smaller than they should be, so it will be interesting to see what results you get.

Sat Jul 05, 2008 12:47 am

Yeah the diameter has been reduced so the m20 VR sensor was too far away, new sensor should work just fine.

The motor looks pretty good, it's all been low budget. DIY ECU, DIY inlet manifold and bike ITB's.

Sat Jul 05, 2008 12:58 am

I was thinking more about the width of the teeth. Dont suppose it matters tho. I was wondering why you chose EDIS, but I guess you have probably ripped it out of another car, to keep the budget down.

Good luck with it. It's a good feeling getting MS running

Sat Jul 05, 2008 1:06 am

I thought i might as well go distributor-less while I'm at it and when I started the project that was the best way I could find to do it. See what you mean about the teeth, they are quite thin, but then in comparison to other engines the m20 trigger wheel is quite thick as stock. Can but try it.

Should I start a new thread for the remainder of the build?

Sat Jul 05, 2008 1:20 am

Using a coil pack would have been easier. No need to pull teeth.

Might be worth starting a new thread, if your doing a complete write-up, otherwise keep it here? I assume you have seen mine... (link below).

Sat Jul 05, 2008 1:35 am

I am using a coil pack, from an st24 mondeo along with the EDIS and VR, although the GM coilpack on your site looks as though it fits m20 plug leads (mine needed slight mods). I'm sure I can ditch the EDIS (and will eventually) but I just need to get it running for now.

I'm more of an engineer than a computer whizz so I thought I'd adapt as much as I can (within reason) mechanical wise to save work elsewhere. A lot has come about since I started the build, I like the motronic conversion for a start. This would have obviously simplified things but was not around at the time.

Sat Jul 05, 2008 2:12 am

Sorry, I should have elaborated, and said coil pack, with individual drivers. 3 drivers, in wasted spark mode. They are easily mounted in the MS box, or as I use, a separate outboard pcb.

I have a two Megasquirt Plug and Play kits to build this weekend. One of them is for a Volvo, with coil on plug. It uses the same case & 55pin socket as the E30's.

Sat Jul 05, 2008 2:31 am

That's something I'd like to look into; 3 drivers internally mounted.
Could coil on plug be made to work with an m20? just thinking about how close the coils would be to the exhaust etc.

Wed Jul 09, 2008 7:53 am

Well I don't believe it, changed the VR circuit, sorted the stims power supply and still nothing, it wont communicate again. Removed MS2 jumped pins 12 and 13 and got comms using hyperterm. With MS2 fitted it just won't communicate. It can't be the firmware because MS2 downloader won't connect to update the firmware, although it has done before. Have I knackered the processor?

Wed Jul 09, 2008 9:50 am

Sounds like a bad connection to me. Run your soldering iron over all the main joints.

Wed Jul 09, 2008 12:44 pm

I had all these issues back in the day, fixed them, then got another batch to sort out!

bad conections and dry joints, misvalued resistors and backwards bits all screwed me over to start with.

And I also fried the chip and the fuel drivers too, I know how I did that and I'm not telling!

I use the VR with a GM coil pack running wasted and loving it!

Pics and info, more more, keep it coming!

Wed Jul 09, 2008 1:03 pm

One of my customers reported connection problems. They were putting 12+ up the +5v TPS VRef

How it didn't blow up the CPU is anyone's guess.

If you building from scratch You need a bit of patience with this stuff. Mistakes are easily made when your eager to get it installed. I have been commissioned to build one for a Volvo. I'm taking my time to get it right first time to save hassles later on.

Fri Jul 11, 2008 8:41 pm

Thought I'd leave a couple of under bonnet shots, its a bit messy I know. One of the fuel rails is disconnected theres leccy tape on the cam cover and the loom needs wrapping. I've yet to make a plenum for it, smaller servo etc.

When it's a bit tidier I'll start a fresh thread for it.