Protecting MS on first plug in

[Challenger]

What are the best precautions to take when first hooking up your MS to your wiring harness? Of course I have the MS fused with the specified fuse, but are there any additional things to do to be as safe as possible on first starting out? What other ways are there to destroy the megasquirt unit or any of its internal components?

 

Ive tried to follow the wiring diagrams Ive found, and I am pretty condfident about what I have done but, I dont want to buy more than one megasquirt ECU... haha

 

Thanks

Edited December 2, 2011 by Challenger

[mobythevan]

One thing you can do is disconnect the coil or external ignitor if you have one. A lot of times people end up with the wrong settings that have the coil powered constantly while they are trying to make sure basics are working like tps, sensors, fuel pump. Then the ignitor burns up. I don't think this is an issue with newer boards that use the current limiting FETs, but it is easy to do.

[Challenger]

I assume that would mean unplugging the edis module and coil in my case? Yeah I would love to have it hooked up with all the sensors functioning before I get to in depth.

Edited December 2, 2011 by Challenger

[Noddle]

I know for me, my biggest concern was frying Megasquirt when I first powered it on,

 

so before I plugged Megasquirt into the harness, I turn the ignition on, and used a multimeter on the DB37 plug, to make sure 12volts and earth were on the correct pings

 

after I was happy with that, I turned it all off, and connected megasquirt into the harness,

 

I made sure it was quite, then turn the key to 'on', listening to make sure the pump started, and no other noise was heard,

 

then turned the key to start, and waited for it to fire..

 

I did preconfigured megasquirt when I had it plugged into the Stim, so I knew it 'should' fire with the setting I had used.

 

once it fired, I was very relieved..

 

then the fun part, tuning..

 

Nigel

Edited December 3, 2011 by Noddle

[FricFrac]

I'm assuming you've already tested your MS or you bought it prebuilt. If you are building it part of the build is to confirm some test points along the way. Once you've tested the MS with your stimulator and install it in the car all I hooked up was power and verified it was working OK. After that I hooked up everything else except for the ignition and injectors. Once I had everything calibrated I hooked up the ignition system and tested for spark with the output test mode. ONce I had spark tested I hooked everything up and tried to fire up the system.

 

I did have a problem before I hooked up the ignition system. I'm running off the stock harness with an adapter I built for my S130. When I turned the ignition on the fuel pump wasn't coming on. Checking the schematics I saw that the stock ECU sends +12V to the fuel pump relay coil which is grounded on the other side - MS turns ground on so I was putting ground on both sides of the relay coil. Made a little relay in my adapter harness that takes the GND signal from the MS and outputs 12V to the relay and up she came.

[Challenger]

Ill be buying it hopefully this winter pre-built.

 

Ive checked everything pretty thoroughly, and stuff has 12V where and when it needs to. I've checked grounds for everything, everything seems to be ready. Im kind of concerned that I may have hooked something up to where it could get to much current... I understand ohms law, parallel/series, current/voltage laws so maybe I am just over thinking it....

 

Related question, I will not be using the fuel pump relay output from megasquirt, I have my own system wired up separately, will not having a pin on this output be problem?

Edited December 5, 2011 by Challenger