2TC 3TC with 2TG EFI and Megasquirt "How to" Guide

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Foxau2
Posts: 60
Joined: Fri Jun 21, 2013 9:26 pm
Location: Clearfield, UT

2TC 3TC with 2TG EFI and Megasquirt "How to" Guide

Post by Foxau2 »

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.

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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.

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You can see some of the dirt and corrosion that appeared on the board after 2 years of almost daily driving.

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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.

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Here is a better picture of the adapter plate.

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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.

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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.

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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.

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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.

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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.

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Here is a bolted on mock up. Looks pretty good!

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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.

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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.

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I wanted to turn the TPS around because I think it looks dorky with the wires pointing forward.

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Problem is it won't fit how it is now. I have modified it and it fits correctly now. Pictures are later somewhere.

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This is how the ECU will be mounted. I cut a hole in the back of the glovebox.

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The fuse/relay block will be mounted directly underneath the ECU.

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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.

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You can see how I mounted the idle air controller in this picture.

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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.

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The EDIS controller is mounted on the firewall next to the washer reservoir.

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Last edited by Foxau2 on Mon Mar 03, 2014 4:55 pm, edited 3 times in total.
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User avatar
Foxau2
Posts: 60
Joined: Fri Jun 21, 2013 9:26 pm
Location: Clearfield, UT

Re: 2TC with 2TG EFI and Megasquirt "How to" Guide

Post by Foxau2 »

I was having troubles with the TPS pointing the wires in the wrong direction, but couldn't use my current "fixed" TPS because the throttle body on this isn't flush with the edge of the plenum. I came up with a solution that will work. I just need to beautify it a bit more.

I just flattened it out completely, then moved the right angle bend in about 3/8" or so. I still need to go find another TPS at the junkyard so I can steals it's guts to put in here.


The problem:

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I'm getting close to beginning the wiring portion of the build. The first couple cuts and crimps are always the most nerve wracking!

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Foxau2
Posts: 60
Joined: Fri Jun 21, 2013 9:26 pm
Location: Clearfield, UT

Re: 2TC with 2TG EFI and Megasquirt "How to" Guide

Post by Foxau2 »

I tested the whole fuel system with compressed air and everything looks OK except the injectors. 3 out of the 4 leak air at 44 PSI! :evil: So now I'm on the hunt for another set of injectors.
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Mazota TE51
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Re: 2TC with 2TG EFI and Megasquirt "How to" Guide

Post by Mazota TE51 »

Nice writeup. How hard is it to tune the megasquirt?
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Foxau2
Posts: 60
Joined: Fri Jun 21, 2013 9:26 pm
Location: Clearfield, UT

Re: 2TC with 2TG EFI and Megasquirt "How to" Guide

Post by Foxau2 »

If you have the registered version and a wideband O2 sensor it tunes the fuel table for you. The challenging part is getting the settings correct for a particular setup. It is designed top be able to run pretty much any engine so there are a lot of things you can change to adapt to any setup. Once you get your feet wet with it, it isn't too bad.

Nate
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Foxau2
Posts: 60
Joined: Fri Jun 21, 2013 9:26 pm
Location: Clearfield, UT

Re: 2TC with 2TG EFI and Megasquirt "How to" Guide

Post by Foxau2 »

I tested a couple more injectors and it seems they might work, well have to see.

Before you start cutting any wires, print out the Megasquirt wiring diagram. I printed the EDIS diagram on the back then laminated it. I used MS paint to modify mine to exactly how I was planning to wire the car. Feel free to use it if you want. Most notably is the addition of the relay to control the AC clutch down at the bottom.

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I built brackets to mount the fuse box to the top of the megasquirt out of some pieces of aluminum I had. It turned out quite nice.

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After I had that mounted I started on wiring the fusebox. I was able to take it in and do it on the kitchen table in the AC which was nice because it was scorching hot in my garage.

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After I had it wired how I wanted, I needed to add connectors so the harness could be disconnected and installed in the car. Otherwise once the engine is wired I would have had no way to get it out. I used all standard size/shape Toyota connectors. All new of course.

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Next on the list was to wire the EDIS module. I sourced all new pins for it so I wouldn't have to solder anything. It is mounted on the firewall next to the washer reservoir.

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I wasn't going to be able to fit the braided stainless hose between the regulator and the end of the fuel rail so I had to go with aluminum hard tubing.

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I needed a fitting that would go from a 3/8" aluminum to a -6AN ORING fitting, but such a thing simply doesn't exist. I knew the threads were the same between a regular -6AN flare and -6AN ORING, so I took the hard line adapter I already had, and simply ground off the flare, then put the o-ring on it. Works perfectly!

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This shows you how I set up the plumbing.

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Foxau2
Posts: 60
Joined: Fri Jun 21, 2013 9:26 pm
Location: Clearfield, UT

Re: 2TC with 2TG EFI and Megasquirt "How to" Guide

Post by Foxau2 »

I was able to get the car running using starter fluid over the weekend. I didn't have the vacuum line connected to the ecu so the ignition was super advance causing it to ping like crazy. But that had me excited! Here are some more pictures.

This is what the wiring looks like before wrapping.

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Here is the mostly complete wrapped harness. The two long red wires are for +12V hot and +12V keyed. Up to this point I had been merely holding them to the battery for testing. In this picture the connectors for the coils, coolant sensor, and VR sensor had not yet been connected. The coils and VR are now on, but I'm waiting for a part to connect the coolant sensor so I can leave the stock sensor in it's place. That way the factory dash gauge will still work.

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Here's after everything was assembled for the last time and I've started buttoning things up. I don't have the correct TPS on there yet because I still need to get more parts. That one is on there just for testing.

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This is unrelated, but I built a laser engraver and engraved the Celica logo onto my phone cover. :)

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Foxau2
Posts: 60
Joined: Fri Jun 21, 2013 9:26 pm
Location: Clearfield, UT

Re: 2TC with 2TG EFI and Megasquirt "How to" Guide

Post by Foxau2 »

It runs! I was able to start it up last night. It started up pretty much right away. I had to lean out the table around the idle areas but I had it purring like a kitten in no time at all. :D The O2 sensor is reading properly so I need to double check that, but at least it runs! I wasn't able to let it idle for too long because I didn't have any coolant in it. Hopefully I can at least drive it around the block tonight when I get home. I'll have a video for you guys tomorrow. I was too excited to take a video last night. :P :P
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Foxau2
Posts: 60
Joined: Fri Jun 21, 2013 9:26 pm
Location: Clearfield, UT

Re: 2TC with 2TG EFI and Megasquirt "How to" Guide

Post by Foxau2 »

I'm going in today to get it registered so I can start road tuning it! I drove it down the street and back over the weekend and it felt pretty strong! It feels stronger than when it was running on the GM TBI. I'm certainly not going to want to take it off and send it to my customer. :D

I still have two things left to do:

I need to get another GM IAC connector for the idle control, and I'm still waiting for the piece to install the temp sender. Right now the ECU just reads 180 degrees all the time. That's OK for now because it doesn't get cold at all, and as long as it runs a few minutes it's at that temp anyways. Hopefully I'll have a video for you tonight. 8-)

I'm taking it to a Japanese car show this coming Sunday so I should have some pictures for you then.
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