[dannichols1474]

Originally Posted by davis911s
"Dan

I am doing the same ITB install in my 911 that you did. Mine is a 77 and I also bought the kit from Al. I am up in Canada. I have a few questions if you don't mind helping me since you did this already.

First is the dizzy part. You wrote this...

"Next I rotated the engine manually to TDC on cylinder #1 making sure the distributor (dizzy) rotor was pointing to cylinder #1. I marked the position of the dizzy relative to the engine and then marked the position of the rotor on the dizzy. Then I removed the dizzy and again marked the position of the rotor on the dizzy.

Once out, I disassembled the dizzy to reveal the mechanical advance and then used steel wire to wrap tightly around the posts holding the return spring on both sides of the dizzy thereby locking out the mechanical advance so that the ignition timing advance would be controlled entirely by the ECU. The dizzy was reassembled and reinstalled into the engine. "

My question is , is this part necessary? If so do you have photos of the dissassembly of the distributor and procedure once in there of what you did ?"

Hi Shawn,

Good question about the distributor. In the book "Performance Fuel Injection Systems" by Cramer & Hoffman (from DIYAutoTune.com the big USA distributor of Megasquirt ECU's), the authors state that if you are going to have the ECU control the ignition timing advance, then you need to disable the mechanical advance mechanism in the distributor. That way there is only one master of the ignition advance curve.

I achieved the disabling of the mechanical advance by taking the distributor (Bosch in my car) and removing the springs and replacing them with steel wire, see page 6 of this thread (post #106 & 107) for a step by step procedure with photos.