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My Megasquirt 3X conversion

 
Old 10-08-2011, 12:43 AM
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BigAl1
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Default My Megasquirt 3X conversion

Things are coming together on the engine assy, now at the point of changing things for the Megasquirt 3X conversion on my 1980 Euro S. Since this had CIS originally, there is a little more work in making the injector adapters to the runners and the new fuel rails. So far, I'm using #24 Ford injectors, CKP sensors from a Ford Zetec engine, water temp from a GM LSx engine, and Intake Air Temp sensor from a GM v6 car. The coils are LSx, and everything will be controlled by Megasquirt 3X in full sequential mode.
I have been doing a lot of reading about the finer points of VR sensors vs tooth size on a trigger wheel, and found the MegaManual has a good diagram showing the size of the sensor inside the sensor housing should match the width of the tooth passing by. This should give the "sharpest" rise and fall at the "zero crossing" when looking at the waveform the sensor will output, but still have a strong signal generated. So, I cut open a spare sensor I had and measured the core - it is 0.300" dia, and by pure chance the teeth I had cut on the crank trigger wheel also measure 0.300"! A lucky break, as I was planning to redesign the teeth and have to cut and reweld the crank trigger wheel.
The IAT sensor I mounted where the fuel distributor used to be. My theory is this point is upstream of any oil contaminated air that might come from the crankcase vent, so this sensor should stay clean.
The water temp sensor I tapped into the LH head block-off plate with a M12 x 1.5 thread. I wanted this sensor in the head so it reads the water temp rise as quick as possible, plus that is where GM put it - must be a good reason!
The cam trigger wheel is my own design, and will be pinned to the cam gear when all is aligned in the final setup.
So, the big challenge has started! Most of the steel parts are done for this conversion, still have to do the machining of the injector plugs and rails, then mount the FPR and route the fuel lines. Wiring will be the biggest part of this conversion for me - LOTS of wires to run as I will completely replace the engine harness.
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Old 10-08-2011, 02:03 AM
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Awesome. Keep us posted on the final steps and the wiring and of course the tuning. I think most do not understand how much head scratching is involved with putting these things together.
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Old 10-08-2011, 03:57 AM
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Al, where did you source your VR sensor from? I'm using on off of a Mustang and wonder if its the same size.
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Old 10-08-2011, 10:10 AM
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Please consider moving the clt temp sensor.
It needs to be at the hottest point in the coolant stream which is by far the front of the heads. Or the water bridge in the factory location.
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Old 10-08-2011, 10:28 AM
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I'd like to see your adaptation from the CIS injector port to the elec. inj. port please.
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Old 10-08-2011, 11:01 AM
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When I made my wiring harness I used a half sheet of plywood to build on. I could pin wire down with thumb tacks, and I could use the old harness for reference over the new one. Also I built mine on my kitchen island, the plywood let me move the whole project when I got done working on it each day. I soldered mine together, but since then I bought a profesional set of wire crimpers, If I ever make another harness I will crimp the connections.

Megasquirt is deffinately a lot of bang for the buck. I am running a MSII on my 84 euro fuel only, but I have the stuff to convert the ignition to Ford EDIS, just have not gotten around to doing it.

It looks like you are doing a great job so far. Nice clean engine. looks like you are having stuff plated, nice.

Sam
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Old 10-08-2011, 11:32 AM
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Excellent work. I've said it before, a solution with a more over-the-counter harness, would make all the difference.
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Old 10-08-2011, 12:16 PM
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Thanks for the comments guys. Adam - the VR sensors are from Zetec engines that were in 2002? Ford Focus.
Colin, I'll look at changing the CLT location. Need to understand the coolant flow path on these engines.
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Old 10-08-2011, 01:12 PM
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I will also be keeping an eye on this. I'll be doing mega 3 with batch injection.
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Old 10-09-2011, 12:30 AM
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Just some small progress tonight - got the Idle Air Control valve installed. This is from a 97-98 VW Jetta, plus the formed rubber hoses from the same setup came in handy for this install. I had to make the pipe from the oulet of the IAC to the old cold start injector hole into the plenum. I figured the point of this valve is to bypass the throttle butterfly, and allow more air into the plenum during cold starts or load changes at idle, so this looked like a good path.
I also tried various positions for the LSx coils, using the stock length plug wires. I think I have a very clean bracket idea forming in my head - just need to make a trial version.
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Old 10-09-2011, 09:52 AM
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So whats the deal with the injector boss'? Please post details on how you modified the CIS inj. ports to fit the elec. injectors. I looked at doing this to a Euro intake I have, and decided that it was too much trouble. Maybe I was wrong. I'm looking forward to your solution.

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Old 10-09-2011, 10:30 AM
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Fabio,
I have the aluminum stock, but have not machined it yet. It is simply round bar, with an OD that just fits inside the threads in the runner casting. This will be cut into a plug, then drilled for the 14mm injector o-ring pocket. The outside will have grooves lathed into it so when the plug is epoxied into the threaded hole, it is locked in tight.
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Old 10-10-2011, 10:16 PM
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Fabio - this is for you! With today being a holiday, I got some good time in on the conversion stuff, and decided to tackle the injector conversion challenge. My original plan was to just make a plug to glue into the threaded hole where the CIS injector holder used to be. But, had a rethink and wondered if I could remachine the CIS holder to a 14mm bore. Never have taken one apart before, so had to learn what parts are involved. I had a spare set of runners with injectors, so started figuring it out. Luckily, the injector holders unscrewed by turning with vice-grips, then pushed out the injectors from the rubber sleeve, and removed the rubber from the threaded holder. It is just an aluminum sleeve with the hex hole on top and M24 x 1.5 threads on the outside. I was disappointed there was no meat to machine for a 14mm bore, but then I had a lightbulb flash above my head! Why not turn the holder over and put it down into the threaded port on the runner? Since the Ford injector plastic tip does not pass through the hex hole, then I could just make an adapter sleeve for the ID of the CIS holder down to fit the 14mm O-ring on the new injectors. So my adapter sleeves measure 0.790"OD x 14mm ID x 0.420" long, made from 6061T6 aluminum. With the OD slightly loose, it allows the JB Weld epoxy some room to exist. I left the original thin wall (used to be pointed down) as a place to grab when turning the threads into the port on the runner. All 8 spacers were made and epoxied into the holders, just took a couple hours on the lathe. It was a good afternoon!
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Old 10-10-2011, 10:39 PM
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These are another option, to those people that are following this thread.

'88-92 VW Jetta/Golf Digifant fuel injection cups are essentially what you've made.

Like the ones found here

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Old 10-10-2011, 10:55 PM
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Correct me if I'm wrong but doesn't that leave the injector tip pretty far up inside the runner still?
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