anyone troubleshot megasquirt.
 

the guys on msefi are really slow at replying.
just wondering if anyone on here has troubleshot megasquirt.

i left my megasquirt after fully building it for a couple months.
when i went back to it to continue messing around wiith the settings
megatune no longer responded to my msII v3 ecu being hooked up.
usually the guages all go crazy then down to zero. and you can play with
the settings. mine wont respond to the stim being hooked up.

tried fresh battery
tried rebuilding cable.

any new ideas.

Re: anyone troubleshot megasquirt.
 

yeah skim the megamanual for the 'before you continue, test this...' sections. jump through that real quick to test the simple ---- like the power circuit, communications, etc. See what's working on the board first, if the board is working then you know it's just an interface problem with your pc. Then check your drivers/com settings and ----, are you using a usb-serial converter?

Re: anyone troubleshot megasquirt.
 

im using a 9 pin to 9 pin straight through that i built.
good ideas thanks. ill go ahead and try those. this goes back to
where you type and should see it go through the circuit board and
show up on the little black screen right?

Re: anyone troubleshot megasquirt.
 

the pins on my MS2 daughterboard don't make good contact in the socket. Causes all sorts of screwy issues. I was able to get it to work ok on the bench by gently tweaking each pair of pins towards each other. Now they look sort of like this: \ / \ / \ / \ / etc. VERY SLIGHTLY!!! Other MS2 users ended up breaking pins trying to do this and had to have them repaired ($$$). This got mine working reliably on bench-testing, but there's no way that the daughterboard will hold in securely enough to try it in the car. Gotta devise some scheme to hold it from wiggling loose. Maybe a few dabs of hot glue like I have on my MS1 chip right now ???

Try pressing down and wiggling the edges of the daughterboard into the socket, and see if you can get response on MT or the stim board. It's a very delicate setup. Try not to break anything, it won't be cheap to fix.

Re: anyone troubleshot megasquirt.
 

I took a pic to show what I mean

Attachment 14904

Re: anyone troubleshot megasquirt.
 

I mean you plug the bare board into the stim and check the pins in the processor socket for 5v and gnd. power circuit tested
you jumper some pin on the processor socket and you connect through hyperterminal. yes what you type should show up on the little black screen. communications tested.

those are the spots I'd hit throught the megamanual. shouldn't take but 5 minutes plus it refreshes you how the circuits work if it was a while since you built it.

and like said above, make sure all your components are making good contacts.

Re: anyone troubleshot megasquirt.
 

did that last night. it did refresh me on how the system works. turns out my freakin comm port setting got reset back to comm port 3 instead on comm port 1.
thats pretty annoying if you ask me. all that trouble for such an easy fix. atleast i learned a lot from it. now its all working again. and i got to check my map for
vacuum or pressure and its installed correctly too. next step is installing in the car and tuning.

any advice on the installation.

im thinking about making an adapter cable that will match up all the pins from the original harness to the correlate with the correct pins of the MSII.
good idea or no.

once again thanks for the ideas

Re: anyone troubleshot megasquirt.
 

that's not a bad idea on the adaptor if you plan on problems with the msII and think you may need to swap back to stock ecu here and there. If you do, make sure you have EXCELLENT documentation on the stock wiring harness. Yuriy tried that with his bmw and it was a nightmare cause the documentation he had was 2nd hand and sucked, turns out it wasn't for his exact engine and gave him some grey hairs.

What kind of engine is this? May be easier to take a pair of wire cutters to a junkyard and grab the connectors for your sensors and make your own harness. That eliminates alot of extras the factory harness may include that can cause problems, yet leaves your factory harness untouched in case you need it in the future. Just make sure to use relays and fuses where necessary to protect the msII.

Either way I'd check your wiring with a multimeter a few times before plugging in your msII. no need to fry the thing now that you konw it works with one misplaced wire

Re: anyone troubleshot megasquirt.
 

its going on a 4ag turbo.
i can get pretty reliable wiring diagrams of the oem harness.

i was wondering on the relays and stuff. should i just use my stock ones or do i throw in a couple of
relays in the system. you know how on DIYtuning it shows all this extra stuff you need to buy. like cables and
relays and stuff. i would think that everything is there already and i should just need the new ecu.
except for the mechanicals obviously.

yeah i should protect against voltage spikes and stuff.