A lot has happed since the last post. I'll bundle it up in this post.

ECU
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I finished mounting the ECU under the passenger seat. A hole was made in the center tunnel and the wiring was run through to the engine bay. A hole was also run for the manifold vacuum.

Airbox:
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The EFI system will not use the CIS meatering plate so this part of the air box can be removed. I decided I would modify the airbox that was originally on my 3.0 engine, instead of the airbox I picked up on ebay. The airbox on my 1978 911SC has larger diameter runners than the later year airbox I got on ebay. I figured the bigger the better (grunt...grunt) so I went with the 78 airbox.

I took my trusty dremel tool to it with a 1/8" diameter milling bit and started cutting it up. I removed all the parts that I would not need. Here are some pics:


 

It was kinda painfull cutting up a perfectly good CIS airbox, especially since there are so many owners out there with blown air boxes, but hey I am commited at this point.

Next I needed an air filter. Being the DIY kind of guy that I am , I couldn't just go out and buy a cone filter....no...no.. I must build one from scratch. Well almost from scratch. Here is what I came up with:

And here is the final product. Now I must figure out how to connect the filter to the airbox.


 

Fuel injectors (again)
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I did multiple flow tests on the yellow 19lbs/hr injectors I bought on ebay. In this setup I used a pulse generator to simulate pulses that the ECU would generate. Using pressured water, I compared the flow for the injectors. After much cleaning and retrying I could not get 6 out of the 8 injectors to be better than 10% within each other. I had four that were within 1% but the other four were way off. Once again I needed to find more injectors :(

By this time I had already started collecting parts for my next project. Yes I've decided to turbocharge my 911SC. So I would now look for injector capable of delivering enough fuel for the engine on boost. I picked up some "red top" injectors from ebay. These were rated for 32lbs/hr. Six of these would be good enough for well over 300Hp. I ran flow tests on these and they were with 2% of each other, so this was good news. The original Rochester injectors had had six jets for each injector. The 19lbs/hr Bosch injectors had four jets. These only have one jet. Atomization won't be as good as the the other, but the more jets mean the smaller the holes and the easier they are to get plugged as I have discovered in my flow tests.

While doing all my flow measurements using my fuel rails I noticed that one of them leaked where the brass nipple was brazed to the aluminium. i was never really happy with the weld. I decided I was going to remake the fuel rails, this time only using aluminium. I also changed where the fuel entered and exited from the rail. Here are some pics of the new fuel rails and the injectos:

Installation:
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It is still winter here in Ottawa and my garage is unheated so I am not very motivated to go out and work on the car. This last weekend though it went upto +4C and I took this chance to work. I decided to remove the current CIS system and install the modified air box with the EFI runners. I was able to remove the complete CIS system fairly easily without doing any partial engine drop. I installed the runners and new airbox. here is what it looks like:

The hose that connects the airfilter to the throttle body is too long and results in the deck lid hinges hitting the air filter. I need to fix that. Next the fuel rails were installed with the injectors.

I went out and picked up some fuel injection fuel hose and hooked it up. I turned the key on and let the fuel pump run fuel through the rails. I let it run for a while and looked for any fuel leaks. Everything looked good. I hooked up the injector harness and tried to start her up. I cranked a couple of times and then.....

She started up and was idling!!! hurray!! She was finally runing under the EFI system. The idle was rough but none the less it was running. I looked at my laptop which was indicating the O2 sensor was dead. The next day I went and picked up a heated O2 sensor and installed it. I now have some feedback that tells me if the mixture is lean or rich. The heated O2 sensors (three or four wires) are better than the non heated (one wire) because they give you reliable data when the engine is idling.

There are still some things that need to be fixed. The fuel rails need to have some kind of way to prevent them from poping out of the runners. I will have to fabricate some kind of brace. Also the air filter needs to be fixed.

Note I have reused the stock Auxilary Air Regulator for cold engine idle up instead of the electronic means provided by the Megasquirt unit. I love how clutter free the engine bay is with this setup. It is almost as clean as a engin with carbs.

The tuning fun begins now, unfortunately it is still very much winter here, so any tuning that is done will be with the engine free running.