How To Megasquirt Your 2nd Gen RX-7: Reassemble The Engine Bay

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With all of the wiring complete, the only major mechanical work to do is to simply reassemble the parts of the car you took off to wire up the 'Squirt. At this point we don't want to loom or wrap the harness yet until it is proven the system works, so leave that for the end.

Reassemble The Engine

When reassembling the upper intake, remember to use anti-seize on all the bolts and to follow the various torque specs. Reinstall the upper intake while you reconnect any vacuum lines. Pay careful attention to which line goes to which nipple. Reconnect the throttle cable and make sure it is not too tight. Remember to reconnect the TPS and IAT wires before the intercooler (if applicable) is installed.

Run A Vacuum Line To The Megasquirt

In order to sense engine load the Megasquirt needs to see manifold pressure. The most convenient source for engine manifold pressure is the boost/pressure sensor line coming from the lower intake manifold. Since the boost/pressure sensor has been removed that nipple should be dangling in the open, ready for a vacuum line. MS1/MS2/MS3X users can use a sharp knife to pierce a hole in the wiring harness grommet and slip one end of a long vacuum line through it. Route this vacuum line down underneath the dash to the Megasquirt then connect it to the MAP sensor in the 'Squirt. MS3-Pro users can connect the vacuum line to the MAP sensor previously mounted in the right side of the engine bay near the firewall corner. Now route the engine bay portion of the line away from hot and/or moving parts, trim it to length and connect it to the lower manifold nipple. A small zip-tie will help prevent it from popping off under boost.

Connect The Main Battery Feed

The positive power feed to the Megasquirt wiring was previously left disconnected, so now it is time to connect it. Put dielectric grease on the terminal then connect it to the positive battery post. If you see anything other then a tiny spark, hear, smell or see anything burning, immediately disconnect this wire and find the fault! The breaker will trip if there is a short so any burning means that there is something grossly wrong (like the breaker is backwards or has not be installed because it's "unnecessary"). Stop what you are doing at this point and compare your wiring with the schematic to find the problem.

Onward and Upward...

Assuming the car is not on fire at this point we now move on to programming the Megasquirt and starting up the car.

<< Wire The ECU Panel, Wideband and Fuel Pump

How To Megasquirt Your 2nd Gen RX-7
Prerequisites And Requirements
Parts List
Building and/or Modding The Megasquirt MS1/MS2
Modding And Setting Up Megasquirt MS3X
Remove Stock Wiring and ECU
Modify Stock Wiring
Mount The Megasquirt ECU
Install CLT and IAT Sensors
Wire The Megasquirt MS1/MS2 Harness Into The Car
Wire The Megasquirt MS3/MS3-Pro Harness Into The Car
Wire The ECU Panel, Wideband and Fuel Pump
Reassemble The Engine Bay
Programming The ECU (MS1)
Programming The ECU (MS2)
Programming The ECU (MS3X / MS3-Pro)
Starting The Car For The First Time
Basic Tuning
Installation Video and Resources
Programming The ECU (MS1) >>

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