The return line formed and in place This is a lot more complicated than it really needs to be. You could actually just install a 2-3 inch stub and then attach a rubber line to it. There's no pressure on it. I went ahead and bent it all the way out because I was in the mood. There will be a bracket holding the lines to the intake. The return line is 5/16" and can use standard fuel line. The supply line is 3/8" and you should use fuel line clamps. There's not a lot of pressure (10-15 lbs.) used on TBI but better safe than sorry.


Oh THIS looks familiar! I went through this on my M115. Looks like a psychedelic spaghetti convention! Initial wiring just to check it out.


Here's the cause of a full wasted day. You wouldn't think BOTH of the injectors I pulled from a Pic 'N 'Pull yard off an 1987 GM product and let set around for over two years collecting dust and grime would be bad, now would you? Yup. They worked at first then quit. Spent a few hours troubleshooting my wiring, relay board and ECU before I realized they weren't "clicking" when I ran the MS in "injector test mode". Replaced them and all was well.


Here's the wiring cleaned up, bundled and routed in the firewall brackets. Just a little better don't you think? I left extra on the relay board end because I know I'll be re-routing it just because of one reason or the other.


The O2 wiring routed along the firewall. It runs under the heat shield back past the transmission. Since this is a 2 BBL TBI I needed to either install 2 O2's (one in each pipe) or install the O2 into where the pipes merged. I went with the single. Since it was so far back in the exhaust system I went with a 4 wire Bosch unit. This is a heated unit so it won't lose the temperature during idle or low cruise. A three wire (no return to the ECU, just a signal, heat power and heat ground) could be used with the same results. I used the 4 and ran a return to the ECU because I had some flaky problems with my M117 conversion regarding a consistent O2 signal and I figured I'd try to eliminate it. My M115 uses a single wire because it is a single injector TBI and it's mounted within 6 inches of the exhaust manifold so no need for a heated unit.


The fuel pump and filter mounting will be the same as I did on my M115 which is shown in the other thread. I haven't done them yet because of course, I just filled the tank up before I started this project and I'm going to wait until it's below a 1/4 of a tank to pull the lines.

I've been driving it around and I must say I'm impressed with the smoothness of the car. I've got a slight "stick" in the linkage coming off idle. Gotta smooth that out but otherwise it just zooms along. A lot more even power curve than the carb ever was and it was a darned good carb. Getting the tuning done now and learning a lot about the Tuner Studios software.

Next step, converting to a Ford EDIS wasted spark ignition. I should do it first on the M115 but I'll probably do it on the M110 since I have the loose engine sitting there which makes it a lot easier to fabricate parts.