Engine swap
Posting Guru
Joined: Oct 2005
Posts: 1,017
Likes: 3
From: Longwood, Fl
I agree with KB---give a lot of thought to going FI on the 5.8.
You will have to mount an aftermarket fuel pressure regulator to regulate the fuel pressure down to the 5-7 psi for the carb. You will need a 3 port, 1 will have to be the by-pass after the 5-7 psi regulation to act as a return to the tank. 1 will be the fuel from the tank, 1 will go to the carb. You will also have to add a leed to fool the PCM into thinking it is receiving pulses from the engine running so it will pull up the relay to turn on the fuel pump. Without it, you "aint" going to get fuel. I have done that on a conversion to carb on a 302. I will have to look back to refresh my memory. I'm thinking it is the tach signal, wired to the correct term for the PCM---dont hold me to that--yet
Do the 87's have the ignition module mtd to the side of the distributor?
You will have to mount an aftermarket fuel pressure regulator to regulate the fuel pressure down to the 5-7 psi for the carb. You will need a 3 port, 1 will have to be the by-pass after the 5-7 psi regulation to act as a return to the tank. 1 will be the fuel from the tank, 1 will go to the carb. You will also have to add a leed to fool the PCM into thinking it is receiving pulses from the engine running so it will pull up the relay to turn on the fuel pump. Without it, you "aint" going to get fuel. I have done that on a conversion to carb on a 302. I will have to look back to refresh my memory. I'm thinking it is the tach signal, wired to the correct term for the PCM---dont hold me to that--yet
Do the 87's have the ignition module mtd to the side of the distributor?
Lead Driver
Joined: Sep 2002
Posts: 9,182
Likes: 12
From: Gateway to the West
The signal needed would be the PIP sensor from the distributor because that's what tells the PCM what the spark timing is. This gives the PCM enough information to calculate the necessary fuel delivery rate.
I have to agree with both these guys though... its a nightmare of a change to go backwards with technology here. And with the EFI you have the EEC-IV system that will basically TELL you what's wrong with it IF something goes wrong. Beats the heck out of hunting down the problem and spending hours and dollars replacing parts that may not be be cause of the problem.
Oh and if I can throw one more potential issue at you... EFI will keep running with the truck way off camber. Haven't met a carburetor yet that will do that safely.
I have to agree with both these guys though... its a nightmare of a change to go backwards with technology here. And with the EFI you have the EEC-IV system that will basically TELL you what's wrong with it IF something goes wrong. Beats the heck out of hunting down the problem and spending hours and dollars replacing parts that may not be be cause of the problem.
Oh and if I can throw one more potential issue at you... EFI will keep running with the truck way off camber. Haven't met a carburetor yet that will do that safely.
Thread Starter
|
New User
Joined: Jan 2009
Posts: 4
Likes: 0
maybe I worded this wrong. The 302 removed was an EFI, but the 351w installed was from an older bronco, late 70's is my guess. It already had a Edelbrock manifold and carb installed along with MSD ignition and distributor. It has the mechanical fuel pump installed as well. The PCM is not even on board any more. Nothing is EFI on the truck itself. I have custom gauges installed. The original wire harness from the EFI engine is still there and I want to remove it to clean things up.
Lead Driver
Joined: Sep 2002
Posts: 9,182
Likes: 12
From: Gateway to the West
Ah, well then most of the harness can come out. The EEC-IV sensors compound the number of wires in the harness by about two or three per sensor. You only need to get power and ground to those locations that require it. Since the EEC-IV wiring harness terminates primarily at the PCM, anything running back that way can go.
What ignition system are you using? That will determine the bulk of the wiring requirements for the engine that is in there.
What ignition system are you using? That will determine the bulk of the wiring requirements for the engine that is in there.
Thread Starter
|
New User
Joined: Jan 2009
Posts: 4
Likes: 0
See what I figured was the only wires I needed to run were ignition, lighting, carb (since its electric choke), gauge wires and any accessory I plan on using. Would this be correct? or am I leaving something out?
Trending Topics
Lead Driver
Joined: Sep 2002
Posts: 9,182
Likes: 12
From: Gateway to the West
Nope, sounds like you've got it covered. As long as you have everything in place for the charging system everything else is just whatever you decide to add for your own convenience.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Cargo Master
Joined: Mar 2006
Posts: 2,789
Likes: 5
From: Sand GAp, KY
I love to see the old stuff being used! As you can see by my signature, I now only need one hot line to keep my beast alive. Can't believe the looks I get when people hear the diesel clack and see the black smoke in their face from a Bronco at stop lights!
