Distributor for megasquirt harness

2.2L Engine N/A None turbocharged
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Morgan1992
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Joined: Tue Jan 12, 2021 7:09 pm

Distributor for megasquirt harness

Post by Morgan1992 » Tue Jan 12, 2021 7:15 pm

Need to know what two wires from 6 wires on the connector I need for the harness

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1stgenWizard
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Re: Distributor for megasquirt harness

Post by 1stgenWizard » Tue Jan 12, 2021 11:24 pm

For megasquirt you need to modify the distributor to work, not plug and play. thanks to the topic over at Mx6.com
Modifying the turbo distributor.


For Megasquirt, we need a RPM input. The simplist way to achive this input on the turbo engine, is using the factory VR sensor and trigger wheel. BUT, in order to do this, we must modify the factory 24-tooth wheel so the VR sensor can provide the signal in terms that Megasquirt can reconize. Since RPM is based on the rotations of the crankshaft, and the pick-up wheel is located in the distributor where the camshaft turns at half the speed of the crank, we must set up the distributor in a way to "trick" the MS in to thinking we are triggering off the crank. We can achive this by removing two teeth from the factory pick-up wheel in the distributor. This spits the wheel in half, giving us a 12-1 wheel (11 teeth, one missing). This allows us to split the cam cycle into two seperate cycles to match the crankshaft. The first tooth starts the ignition pick-up cycle, and the missing tooth signals for the megasquirt to "start over" the ignition event.


To start the modifications, remove the cap, rotor, and protective cap.
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Remove the two sensors on top by first removing the 4 phillips screws (2 per sensor). Then cut the wires attached to the sensor and discard them.
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You should now have this:
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Next, remove the “spacer plate” retaining screws. Lift out the plate and discard.
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Next, remove pin from drive “gear” on the cam side of the distributor. You can use a hammer and punch. Using a sharpie or equivalent, make a spot on the “gear” and the shaft, this way you can re0assemble them back together correctly.
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Inside the distributor, remove the two phillips screws at the bottom. This holds in the center shaft. Once removed, you should be able to easily remove the distributor shaft.
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We can now modify the distributor to work with megasquirt. We want to modify the bottom wheel, not the top. You want to grind down two of the “teeth”. Looking at the top wheel, at the point, count back four teeth. We want to remove the forth tooth. Mark this tooth.
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We also want to remove the tooth directly opposite of this one. Count 12 teeth (in either direction). Make the 12th tooth. Make this tooth, as we want to remove this one as well. You should have 11 teeth between the two marked teeth on both directions.
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Now, grind down the two teeth. You can use a Dremal tool, a drill with a grinding/cutting bit, air tool, etc. TAKE YOUR TIME! Go slow and take off a little at a time. We are working in a small space with very little material, and you DO NOT want to damage the surrounding teeth. If you happen to “nudge” one, its no big deal, just try to avoid them as much as possible.
This is what you want:
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Once this is complete, clean the distributor shaft of ALL metal shavings. Re-assemble the distributor shaft into the distributor housing. Install mounting screws. Reinstall the distributor drive gear and retaining pin. Be sure to line up the marks you made earlier.
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Re-install the rotor and cap and your done!

"So once you remove the other sensors by cutting them out, you can then use an ohmmeter to locate the pins to the single sensor left.)
8-)

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