I am currently in the process of installing a megasquirt conversion on my 1976 SLC. I have been reading Oughtsix’s conversion, and I have decided to follow his advice almost to the t, except for building my own MS computer. I do not feel confident that I will be able to do a good job welding, as I have tried it in the past, and it has never quite worked for me.
So far this is what I have done:
1. Removed Intake manifold. I had a severe issue with vacuum loss (traced to a nice hole in the pipe coming from the exhaust for the EGR, and the fact that the Air control valve was stuck in open), and needed to isolate the problem, so I decided to remove the intake to replace those pesky rubber spacers in between the upper and lower manifold. This also helped me to clean, and seal the intake in a much better fashion. I also used Eastwood’s Co. Alumablast to refinish the top of the intake, and it looks so much better.
2. Had the thermo-time switch rebored for the 3/8NPT pipe thread needed for the CLT. I also took off any of the CIS components (Warm Up Regulator, Idle Control Valve, and the Air Distributor).
3. Purchased 8 19 LB mustang injectors. Tested the injectors and they do not need to be machined down, and the fit is nice and tight.
4. I took the old CIS Air intake, and sealed the CIS portions, and took out any moving parts… Including the Fuel Distributor…. Painted it with Eastwood Detail Gray, and drilled and tapped out a nice hole for the IAT... Figured that it would look really nice on the outside of that monster.
5. Removed all the accelerator linkages, stripped them, cleaned them, painted them with Eastwood black, and reassembled them. Now they have nice and smooth movements, and are not binding.
6. Bought the idle control box, and a 1992 Jeep IAC valve and tapped out two m6 bolts on the side, and I am using the bracket that used to belong to the WUG for it. Now need to get the right combination of hoses to connect it to the air distributor, and the (now inert) CIS intake. This should work as I am taking nice clean filtered air from the CIS, and through the air regulator am going to the intake manifold after the throttle body. BTW, the reason that I kept the original huge CIS intake was to keep the even bigger Air cleaner on top of it. I will eventually add a cold air intake, but more like the 560’s version that still has the large air cleaner… The reason for this is to have a large filter that allows more air in and gets dirtier less. (And still keep some semblance of originality).
7. Bought new bolts. As I had cap head hex bolts, I chose to replace them, as they tend to stretch and lose some of their strength after repeated torqueing.
8. Bought the Relay panel, the CLT, and the IAT from DIY autotune.
9. Cleaned the V of the engine block, and painted with temp. resistant black.
The idea is that anything that gets touched/removed is cleaned, and if needed stripped, painted, and reconditioned if possible, or replaced.
The plan as of today is to get some parts in (replacing the heater hoses that run UNDERNEATH the intake manifold) before dropping in the reconditioned manifold.
After the intake manifold is in, the injectors with new seals will be put in the car, and the electrical will start. I have decided to use the negative post of the coil for tach input, and wire the fuel pump from the relay board for safety reasons (the 76 had the safety switch on top of the CIS housing, and that got deleted as it would not be used, or useful.).
I will post some pictures of the work so far, and would appreciate any comments, and recommendations. I have found oughtsix’s site extremely helpful, but any other ideas would be greatly appreciated…. And no, there is not talking to me about keeping the CIS, as these systems are not well supported, or understood… They might have been state of the art in 1976, but…. Now, they are just a pain.
I do have a couple of questions though. I still need to find a nice power lead that is on both at run and at crank. I was thinking of using the lead coming from the old fuel pump relay, but are there any other ones closer to the engine compartment? If not, it is not a huge issue, as I need to run cables to the engine anyway.