just installed a megasquirt built for the 420a. installed it correctly by the "simple wiring diagram" that was included with it. by the diagram some of the wires were not the same color as the pinout on the connector. i just went by the pinout by the diagram. the coils are hooked up by two iac wires. that just doesnt seem right, but by the diagram thats what it said to do (by the pinout not color). everything is wired correctly (if the diagram is right) as i know the ecu pinouts i have are correct. im just lost as to the wires from the megasquirt being right. i just dont understand how those iac wires would control the coil unless it has been made that way.

but anyways, we have no spark nore injector pulse. i know my wiring is correct, but i cant say the same for the megasquirt diagram being correct. if anyone has wired the megasquirt up to retain the stock ecu for idle, fan, etc. control could you give me pinouts/ wire colors to hook this thing up. i dont know if the crank signal is working (crank sensor works), or if the diagram is wrong, or if the grounds are bad, i just dont know. also, when you turn the key on, does the megasquirt light up at all? this one wont, but when you crank, the lights strobe in a line.

I am a MS newb too but from my little MS experience I would suggest getting a stimulator. It would let you get more familiar with your megasquirt unit before you let it rip on the ride.

Check out this video. It isn;t our car but it will give you an idea of how to test your MS.

Who built your MS? To run fuel AND ignition with the MS on the 420A, the MS board has to be modded in order to run ignition control. Since we dont use the IAC feature, whoever modded the board may have run the spark outputs on those wires. I suggest to open the case up, and check it out. The two outer LED's on the front of the case, are your spark triggers. Inside you should see a wire going from each of these LED's to the DB37 traces somewhere. You need to "trace" the path of the board's traces from those wires, to see exactly where the spark output's are on the DB37 plug. Make sure you have the CRANK sensor signal wire going to the tach input to the MS, not the "tach" signal wire. Make sure you have "neon" set in the codebase functions, and only that set. This should be a starting point for you.

13.5 @108 MPH-2.2 60ft(stupid FWD!)
S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential
fuel injection)
My webpage: http://eclipsed4evr.home.comcast.net
-1998 Mitsubishi Eclipse RS-T- "Toy"
-1992 Plymouth Laser Turbo AWD(SOLD)
-2000 Honda CR-V(daily)

okay figured it out. the guy sent a bad wiring diagram. i kind of figured that at first. then the proper code wasnt in it, so i had to reboot the thing. after that i had it running for 30 seconds till i said to shut it off so we could get some cheap spark plugs for tuning. come back, wouldnt start. i had to leave to go to work, then he says the megasquirt fried. well i decided to come back the next week, swap spark control back to stock, and tried to start it. nothing but i found he said he used someones settings off ms-extra, so i went in and swapped it back to my settings and started it. SUCCESS!!!!!! but it needs new sensors as that is screwing up the tuning as the readings are like half what they should be. im going back next week or a few weeks, and get it tuned.