2TC 3TC with 2TG EFI and Megasquirt "How to" Guide
Posted: Fri Jun 28, 2013 7:31 pm
It makes me sad that all the info was lost when the forum went away, but I understand these things happen and the best we can do is keep going.
I am building this for a customer. He requested that I keep his identity hidden until after I deliver it to him.
The plan is to put the 2TG EFI stuff on a 2TC motor. He will have a 3TC but as far as the install goes it's the exact same.
When I bought my 2TG stuff the guy had already built an adapter plate for it, and it was included in the sale.
I will be using my 77 TE51 liftback to build it up. It will be going into a 74. My liftback had already been converted to EFI using a GM throttle body and Megasquirt. It ran quite well. I was using the relay board, but this one will all be hardwired with a dedicated fuse/relay panel. The ECU will be mounted in the glovebox.
This is the setup I had for EFI before I went this route with the 2TG stuff. I had a TBI from a late 80's GM something or other. I had the single barrel, but if I were to do it again I would go with the double barrel. It's a lot more common in the junk yards. I was using the megasquirt relay board for wiring and EDIS for ignition. This setup worked quite well.
This is my relay board. I blew a fuse and didn't have a replacement so I stuck a brass connector in there. Smart eh? The wiring wasn't very clean or efficient, but it worked.
You can see some of the dirt and corrosion that appeared on the board after 2 years of almost daily driving.
This is just a picture of all the separate components of the 2TG EFI manifold. The adapter plate is at the top of the picture.
Here is a better picture of the adapter plate.
I tapped both ends of the fuel rail to accept a converter to -6AN fuel fittings. One end was tapped to 3/8NPT and the other end 1/2NPT. The adapters are aluminum and commonly available on eBay.
You can see the two brass plugs. I tapped them to accept a 1/8NPT plug because I wasn't going to be using the holes. The large one in the bottom center was tapped to 3/8NPT. It could be used for an air temperature sensor, but I'm using it as part of the idle air control valve circuit.
This shows the adapter plate attached to the block. The holes in the plate without bolts in them are what the manifold will bolt to. They are tapped to a standard metric size. (I didn't build it so I don't know for sure, but it's the same size as the standard manifold bolt.) They are recessed into the plate so they don't interfere with the 2TG manifold.
The guy I bought it all from built the adapter, and this was his solution for the ends. There is enough space that he could have just used another bolt, but he felt these were better. Problem is that it interferes with the distributor.
I had to leave this one off the distributor side because I could get the distributor in. It's been running 8 months now and I haven't had any problems.
Here is a bolted on mock up. Looks pretty good!
I tapped the top of the fuel rail to accept a 1/8NPT fuel pressure gauge, but it collided with the original port used for brake vaccum and PCV. I solved it by tapping it to 1/8NPT using a 90 degree barbed fitting. You can see it in later pictures.
The original throttle cable wasn't long enough so I had to build a new one. I bough a gocart throttle cable on eBay and cut it to size. I know I have pictures of it somewhere, but I can't seem to find any right now.
I wanted to turn the TPS around because I think it looks dorky with the wires pointing forward.
Problem is it won't fit how it is now. I have modified it and it fits correctly now. Pictures are later somewhere.
This is how the ECU will be mounted. I cut a hole in the back of the glovebox.
The fuse/relay block will be mounted directly underneath the ECU.
Here you can see that I mounted the fuel pressure regulator between runners 2 and 3. I had to make an aluminum hard line between one side of the regulator and the fuel rail. There wasn't enough room to use the braided stainless hoses here. The fuel comes in from the fuel pump through the black fitting at the right side of the fuel rail. From there it goes through the rail and injectors. What isn't used goes to the regulator then back to the tank.
You can see how I mounted the idle air controller in this picture.
I fiberglassed the outside of my glovebox so it wouldn't crumple to bits with the ECU sticking through it. I used a UV cure resin and did it one row at a time. Took me about 10 minutes start to finish.
The EDIS controller is mounted on the firewall next to the washer reservoir.
I am building this for a customer. He requested that I keep his identity hidden until after I deliver it to him.
The plan is to put the 2TG EFI stuff on a 2TC motor. He will have a 3TC but as far as the install goes it's the exact same.
When I bought my 2TG stuff the guy had already built an adapter plate for it, and it was included in the sale.
I will be using my 77 TE51 liftback to build it up. It will be going into a 74. My liftback had already been converted to EFI using a GM throttle body and Megasquirt. It ran quite well. I was using the relay board, but this one will all be hardwired with a dedicated fuse/relay panel. The ECU will be mounted in the glovebox.
This is the setup I had for EFI before I went this route with the 2TG stuff. I had a TBI from a late 80's GM something or other. I had the single barrel, but if I were to do it again I would go with the double barrel. It's a lot more common in the junk yards. I was using the megasquirt relay board for wiring and EDIS for ignition. This setup worked quite well.
This is my relay board. I blew a fuse and didn't have a replacement so I stuck a brass connector in there. Smart eh? The wiring wasn't very clean or efficient, but it worked.
You can see some of the dirt and corrosion that appeared on the board after 2 years of almost daily driving.
This is just a picture of all the separate components of the 2TG EFI manifold. The adapter plate is at the top of the picture.
Here is a better picture of the adapter plate.
I tapped both ends of the fuel rail to accept a converter to -6AN fuel fittings. One end was tapped to 3/8NPT and the other end 1/2NPT. The adapters are aluminum and commonly available on eBay.
You can see the two brass plugs. I tapped them to accept a 1/8NPT plug because I wasn't going to be using the holes. The large one in the bottom center was tapped to 3/8NPT. It could be used for an air temperature sensor, but I'm using it as part of the idle air control valve circuit.
This shows the adapter plate attached to the block. The holes in the plate without bolts in them are what the manifold will bolt to. They are tapped to a standard metric size. (I didn't build it so I don't know for sure, but it's the same size as the standard manifold bolt.) They are recessed into the plate so they don't interfere with the 2TG manifold.
The guy I bought it all from built the adapter, and this was his solution for the ends. There is enough space that he could have just used another bolt, but he felt these were better. Problem is that it interferes with the distributor.
I had to leave this one off the distributor side because I could get the distributor in. It's been running 8 months now and I haven't had any problems.
Here is a bolted on mock up. Looks pretty good!
I tapped the top of the fuel rail to accept a 1/8NPT fuel pressure gauge, but it collided with the original port used for brake vaccum and PCV. I solved it by tapping it to 1/8NPT using a 90 degree barbed fitting. You can see it in later pictures.
The original throttle cable wasn't long enough so I had to build a new one. I bough a gocart throttle cable on eBay and cut it to size. I know I have pictures of it somewhere, but I can't seem to find any right now.
I wanted to turn the TPS around because I think it looks dorky with the wires pointing forward.
Problem is it won't fit how it is now. I have modified it and it fits correctly now. Pictures are later somewhere.
This is how the ECU will be mounted. I cut a hole in the back of the glovebox.
The fuse/relay block will be mounted directly underneath the ECU.
Here you can see that I mounted the fuel pressure regulator between runners 2 and 3. I had to make an aluminum hard line between one side of the regulator and the fuel rail. There wasn't enough room to use the braided stainless hoses here. The fuel comes in from the fuel pump through the black fitting at the right side of the fuel rail. From there it goes through the rail and injectors. What isn't used goes to the regulator then back to the tank.
You can see how I mounted the idle air controller in this picture.
I fiberglassed the outside of my glovebox so it wouldn't crumple to bits with the ECU sticking through it. I used a UV cure resin and did it one row at a time. Took me about 10 minutes start to finish.
The EDIS controller is mounted on the firewall next to the washer reservoir.