Posted by jcn (IP: 198.51.174.130) on November 09, 2000 at 10:41:00:
In Reply to: Re: late model 5.0 fuel injection conversion questions.... posted by Mark S. on November 08, 2000 at 18:05:27:
:
: I converted my '77 to fuel injection...I used an '86 Mercury Marquis as the donor car. As far as the wiring, I cut the wiring off right at the firewall and took the whole harness.This way,all the wires going to the sensors and such are there. You can just snip wires going to the headlights,etc.,since they don't directly connect to the FI. Using a wiring diagram for the Marquis and my Mav, I matched up all the relevant wires. I believe there were connections for start,run,constant power and a connection for the AC compressor(if you have one). I also cut a hole in the firewall near the driver's side to mount the ECM (main computer module), so it was similar to a stock Ford application. What I did was to mount the entire intake right on my 77 motor, so I don't know about late model motor mounts. The first problem I found was that the supports from the shock towers to the firewall will not fit any more. I have seen another Maverick with FI that uses a brace that goes straight across the engine compartment...probably what I will do eventually. No problems with hood clearance,though!
: The other problem was that the opening to the throttle body was 1/2" from the master cylinder(I have power brakes on the Mav) I eventually borrowed the intake off of a Mustang that faced the passenger side and put it on..now I can put on an air filter.I also had to change the fuel rail and the throttle cable to accomodate the reversed upper intake...I didn't have to change the lower intake...it works with upper intakes that face either way. I never have figured a good solution to add a "kick down" cable to my C-4..the original lever simply won't work.
: Another consideration is fuel delivery. This FI needs fuel pressure of around 30psi(I believe that is accurate!!), so you will have to add an electric fuel pump. I used an aftermarket add-on that I mounted near the fuel tank. I got the trunk mounted fuel shut off switch from the donor car and ran the circuit through the switch. The switch automatically shuts off the pump if (heaven forbid!) you are in an accident. Another problem I ran into was the fuel return. I was lazy, and I didn't want to run a separate fuel return line back to the fuel tank, so I used a "T" and just piped it back into the fuel line feeding the pump. It worked, but I found over time(like sitting in a fast food drive thru line!)the fuel became too hot(fuel vaporization) and the car would stall. Couldn't get it running again until the car cooled down. I solved this by adding a return port to the gas tank...I added it to the fuel sending unit.
: You also have to worry about the oxygen sensors, although it will run without them, fuel economy will suffer. I drilled holes in the exhaust pipes as close to the exhaust manifolds as possible, and had "donuts" welded in, which are made for just this purpose(don't remember where I got them)
: I did much of this back in '92 and then the car sat for 6 year out behind my house. I have recently rekindled my interest and plan on putting the FI on a '72 Grabber I recently acquired. Believe it or not, after all that sitting, the car STILL runs great!
: I welcome any questions about this conversion..I have access to all kinds of wiring diagrams and FI information if anyone needs help. I plan on making a section dedicated to this on my Mav web site:
: http://www.maverickcomet.com
: Good luck, and sorry this is so long!
: Mark S.