First Start

Today was a really exciting day.  I was able to spend some time in the garage getting my Megasquirt (MS2) connected to the MSM.  My goal for today was to just get all of the pieces connected and to start the car and get it to idle.  I didn't spend any time actually mounting things, so the MS2 unit is currently just sitting on my drivers side floor mat.


I currently have my MAF relocated to the throttle body side of my intake plumbing.  I'm not going to be using that with Megasquirt, so that will need to be removed and my length of aluminum pipe with the GM IAT bung will be taking its place.  The GM IAT sensor uses a different plug than the stock MSM IAT sensor.  I purchased the GM IAT with a plug and pigtail so that I could wire the new plug in tandem with the existing IAT plug.  I just stripped a bit of each stock IAT wire and soldered the new plug onto the existing wiring.  Now both plugs are split off of the stock IAT wiring and I can swap back and forth if needed.


Again, since I didn't have as much time to devote to this today as I would have liked, to save time I just screwed the new IAT into the IAT bung pipe and left the pipe hang out in the open air.  I figured since I wasn't going to be actually driving the car today, ambient air temps would be close enough to idle off of.  I'll need to remove the stock MAF and the IAT bung pipe I purchased from BEGI will be installed there instead.  I went ahead and unplugged the MAF and the other air temp sensor usually located in the factory airbox.


After plugging the newly wired IAT plug in, I ran the required vacuum line to the MS2.  The MSM has lots of those little green and white check valves on almost every vacuum line.  Make sure to avoid those, or at least T off a source before it gets to a check valve.  


I then pulled the 3 plugs from the factory ECU and plugged them into the MS2 harness.  There are several additional wires that can be connected to the MS2 unit to allow you to switch between ignition tables, boost tables, activate launch control, etc.  The only one I was interested in today was the 0-5v wideband input.  I ran the output wire from my PLX wideband to the correct input on the MS2.


At this point, the instructions say to turn the key on and make sure you hear the fuel pump priming.  So I crossed my fingers and turned the key on.  It sounded normal, primed for about 2 seconds.  Good, at least I know something is working :)


Next I needed to setup my project in Tunerstudio and connect my laptop to the MS2.  More info on exactly how to do this is available here:  http://www.miataturbo.net/showthread.php?t=40159  If you purchase from Reverant, he also includes detailed instructions on how to setup the project in TunerStudio, and the ini file you'll need for the ECU.   I've got an el-cheapo USB to serial converter that always seemed to work fine for connecting to routers and switches, so I didn't buy a new one and just prayed this would work for me.  I finished setting up the project, connected the cable and turned the key on again.  Tunerstudio said it was connected, YAY!


Next I need to calibrate the TPS sensor.  Reverent calibrates almost everything in the basemap.  My TPS signal was reading .2 instead of 0 with the throttle closed.  I opened the appropriate menu, clicked "get current" on the closed throttle box, floored it, clicked "get current" on the open throttle box.  Now its correct, time to move on.


Usually at this point in my projects something goes wrong.  I usually need to make 4 trips to the auto parts store and bleed all over something before its made right. Things had been going too well, so I was expecting something horrible any time now.  What can I say, I'm not much of an optimist.  


After stalling as long as I could, and rechecking everything 4 more times, I went ahead and pushed the clutch in and attempted to start the car for the first time.  It cranked only slightly longer than normal, and immediately fired up.  o_0


It was fairly rich, but I attributed that to the warm up enrichment.  It came right up to around 1900 RPM and as it warmed up, eventually settled to around 900 RPM.  It was running very rich however, 11.5 on my wideband gauge.  So I opened the Fuel table, highlighted the 4 cells around where it was idling and clicked the decrease value button once.  Now I'm up to 11.7.  Ok, good... the car is listening to me.  Clicked it 5 more times.  Car sits at 14.5 and idles great.  Click Burn to save the changes, sit in awe of how little time it took me to get this far.


I reved the engine just to see how it would respond.  Everything seemed really normal.  Its a bit rich everywhere, but I expect that.  After all, I've only tuned 4 cells of the fuel map at this point ;)


My wife comes out into the garage, and looks at my laptop displaying all kinds of data about the car.  She says, "that's really cool, now take me out and lets eat some mexican food".  Ok, time is up for today.  So I shut down.


Total time spent in garage, 45 min.  The car starts and idles like stock.  It responds to the changes I make to the fuel table and is ready to be tuned.  I couldn't be more pleased with the progress I made.  I'm very excited to clean up the install and to get out on the road and start tuning.