Another MS3Pro Evo build


Fixer of crap..
Jan 24, 2011
I have been collecting parts for the past few years since I started the restore on my 83.

I considered keeping the original draw-thru system just because it was kind of unique, but it was tired and I was ready for some fun.

The parts list:
Basic 109 block bored .030 over.
Older GN1 aluminum heads
Scat steel crank / 2 steel center caps
Bison's 212/212 Crane cam
Comp 885 Hydraulic Roller Lifters
T&D 1.65 Roller shaft mounted rockers
Siemens 60 lb/hr injectors
IGN1A smart coils
Limited Engineering TA60 Turbo
Weiand 4bbl intake with injector bungs & fuel rail
Holley 4150 Throttle body
36-1 Trigger wheel & hall sensor on the crank

I have an MS3Pro Evo unit that is going to run everything. I have the wiring completed and the engine will fire & run on starting fluid, but I am still waiting on AN fittings for PTFE fuel line. I am hoping to move it from the basement to the garage this weekend and actually try to run it on gasoline with the injectors. Only for 30 seconds or so until I get a cooling system rigged up. I want to do a few full heat cycles on the engine stand before I do the swap.

Megasquirt lessons learned:
the Cam sensor needs a "pull up" resistor for the MS3 to actually see it
The coils / plugs are NOT wired in order.
Do it this way. I thought putting the firing order in the software would tell it what to fire. It doesn't.

I'll update as things advance, but overall I'm quite impressed with the MS3 so far. It has a tremendous support community that seem to know their stuff.
Engine pics and the signal output of the Cam sensor (top) and crank trigger wheel (middle).
We have VROOM! I set up an external fuel pump

Next is to rig up a radiator and let it run for a couple of good heat cycles so I can check for leaks and re-torque the heads.

Also going to weld in some AN bungs to the back of the valve covers for go to catch cans.
Awesome. We now have three EVO users that I'm aware of; ShawnR, dank GN, and Scott Atk. What crank wheel are you using, that composite logger definitely doesn't look like a stock 3x, 1x signal? Keep the posts coming, I've been running for a week now, still learning how to tune it.
Does the regular registered version of TunerStudio have that, or do you need the "Ultra" upgrade?
I am in Ohio (right in the middle) and I don't have a clue who I will have tune it. I put a request on the Megasquirt support forum, but have not had any answers. There are several "tuners" around, but I have yet to find one that knows Megasquirt.
Initially, I thought it would be a cheap way into running EFI. I was going to buy/build an MS2 or 3 box. After adding the extra parts (knock sensor, MAP), I was already getting close to the MS3Pro cost. Black Friday caused me to pull the trigger. FAST was the only other one I considered.

Megasquirt seemed more adaptable to a "Franken-motor" since I have a bunch of non-stock sensors. Holley throttle body makes things weird.
Does the regular registered version of TunerStudio have that, or do you need the "Ultra" upgrade?
Yes, my free version does. Should be under the Tune Analyze Live tab. The only thing additional that I paid for is Mega Log Viewer.
Did 3 different heat cycles today. Brought it up to around 190 each time and then let things cool.
Took a while to get everything set up, but seemed to work pretty well.

I forgot about the little brass plugs that allow you to drain coolant from the block. Nice little wet mess to be standing in right from the start.
Decent oil leak coming from the pan close to the oil filter. I don't think I put any RTV on it because I assumed I would be taking it off again.
The IAC settings are all jacked up. The Holley throttle body uses a standard GM IAC but I can't quite figure out what things should be set at.

It talks about "Home" and "Run" positions, and "steps". It moves in and out when I test it with the software, but when I start the engine, it hangs at around 2000 rpm. If I use the IAC testing settings and tell it to go to the "Run" position, the idle drops down to around 900. As soon as I turn off "Test mode", it rips back up to 2000 rpm again. I'll have to do some reading on that part.

One of the other neat features is the ability to shut off one injector or coil at a time to confirm that everything is working. Very noticeable when you kill 1 coil or injector.

Going to put in a new pan gasket, add some bungs to valve covers for a catch can, and I think I'm ready to stick it in the car.


  • IMG_20200418_191037168_HDR.jpg
    396.4 KB · Views: 238
Engine got installed this evening. Only real issue is the rear coil on the passenger side valve cover is too tight to the AC/heater box. I'll pull the valve cover and move it up 1/4 inch or so. I'm going to get the valve covers and alternator vapor blasted so I was going to pull them anyway.
View attachment View attachment View attachment
To do:
Figure out the hydroboost plumbing
new throttle cable (converted from draw-thru system)
install fuel and oil pressure transducers
install a crap-ton of relays
new fuel tank with internal pump & lines (E85 compatible)
exhaust between downpipe & resonators
I dont like the carb hat thingy I dont think its has good airflow distribution!.