70NE's custom EFI conversion writeup - Part 4

[ForceFed70]

For part 1 of this writeup, go here: http://forums.stangnet.com/showthread.php?t=593406 it will explain alot about the custom EFI system I chose to use (MegaSquirt) and my goals.

Part 4 is gonig to be about the assembly of the MegaSquirt ECU and the electrical wiring.

 

[ForceFed70]

Assembling the MegaSquirt II ECU
Instead of buying a pre-assembled ECU I chose to buy the kit and assemble it myself. While assembling the ECU is not too difficult, it is a time consuming project. It’s probably worth it to spend the extra money and buy a pre-assembled and tested kit. However, I wanted to have the experience of building the ECU myself. Saving about $150 was just an added bonus. The kit I purchased was of excellent quality. It included everything I needed and all of the components were nicely packaged with excellent labeling. Pictured below is the kit as it arrived in the mail.

 

[ForceFed70]

There was probably about 50 or 60 little baggies like this with different components in them. Note the excellent labeling.

 

[ForceFed70]

Assembling the MegaSquirt ECU was a lot easier than I expected. The step by step instructions are very clear and thorough. It’s not something I would recommend to someone who’s never used a soldering iron. But you definitely don’t need to have a lot of knowledge either. The instructions show you exactly where to mount each component, and make sure to warn you when the component needs to be mounted in a certain fashion (polarity for example). Pictured here is the ECU in the early stages of being assembled.

 

[ForceFed70]

The full assembling and initial testing process took me about 12 hours to complete. I actually found myself enjoying the time spend soldering the ECU together. It’s very much like building a model car.
Below is a picture taken a little further along in the assembly process. At certain points throughout the assembly, the instructions walk you through a way of testing the circuits that you’ve just finished assembling. This allows for a much simpler troubleshooting process if the ECU isn’t working properly. Here you can see that I have the stimulator connected to the ECU and I’m using my laptop to see if the input circuits are functioning properly.

 

[ForceFed70]

Here’s a picture of the ECU fully assembled except for the top cover. The whole assembly process went very smooth and I was very happy with the results.

 

[ForceFed70]

The relay board was almost a no-brainer. There was only a handful of components and pretty much only 1 way to install them all. The relay board took only about 1hr to assemble and turned out great.

 

[ForceFed70]

What I decided to do was build a wiring harness based around the relay board. I laid out all of the wires I would need and cut them with plenty of length. Later when it was time to install the harness I would trim the wiring down to length and add the needed connectors.
Here you can see the relay board wired with the harnesses. This harness along with the relay board will connect to all off of the electrical components of the EFI system. This includes: The sensors, fuel pump, ECU, fuel injectors, O2 sensor and controller, and ignition control (for later use).

 

[ForceFed70]

I decided to mount the relay board to passenger side shock tower on the side facing the firewall. This area leaves me access room should I need to replace a fuse or relay, yet manages to stay out of view not too badly.

 

[ForceFed70]

Here you can see the finished portion of the wiring harness for the engine. There is a connector for the coolant temperature sensor, the intake air temperature sensor, the idle air control motor, Throttle position sensor, and the fuel injectors.

 

[ForceFed70]

This is what the wiring looks like with everything connected except the intake air temperature sensor.

 

[ForceFed70]

Here’s a picture of the engine compartment with everything installed. As you can see, it’s difficult to tell this is not a carbureted engine and I didn’t really put much effort into hiding everything. If you were to move the relay board and coolant temperature sensor to a more discrete place, you’d hardly be able to tell at all.

 

[ForceFed70]

Another shot of the engine compartment.

 

[ForceFed70]

OK that's it for part 4.

Part 5 will be all about the tuning.

 

[bnickel]

sweet man, keep 'em coming. just out of curiosity have you already got it tuned and running right or are you still working on it?

 

[NasaGT]

Wow, nice write up, and great pics. Can't wait to see part 5!

 

[Tim65GT]

It's great to see you jumping in there with the funds, time and effort.

But what's really great is you sharing the info.

Nice project and pictures. Can't wait to see the rest.

 

[milner351]

Ditto the above, way cool, and thanks for sharing.

Does Mega squirt make a set up for port injection or only throttle body?

 

[ForceFed70]

sweet man, keep 'em coming. just out of curiosity have you already got it tuned and running right or are you still working on it?

I have the car runnnig, but still need to do alot of tuning. The car isn't insured at the moment... so most of my tuning has revolved around getting it to start properly (various temperatures) and getting the idle tuned.

I still have a fair bit of work to do around starting/idling... but already it's much easier to start and keep idling when cold that how it was with the holley 750DP.

From what I've seen so far, I don't think tuning is going to be a problem. Just need to get some road time to do it.

OH..and I finally have some pics for you. Can you PM me with your email address?

 

[ForceFed70]

Ditto the above, way cool, and thanks for sharing.

Does Mega squirt make a set up for port injection or only throttle body?

The same ECU can be used for both. The ECU is VERY robust and can be configured to run just about any type of fuel injection mentod you can dream of. That's the beauty of a fully programmable ECU...you can do damn near anything with it. From 2stroke dirt bikes to 16cyln aircraft engines.