Bronco V8 fuel injection swap

[Mechrick]

Hi all. Due to the price of fuel, I took the time to covert my BII to fuel injection over the past week. Thought I'd share the process (although there are many routes to accomplish this).
I'll miss the simplicity of the HEI and four-barrel, but I'm hoping for a 3-4 MPG bump over the 14 MPG I've been averaging. I plan to build another MS v3.0 and keep that and a spare TFI module in the vehicle for redundancy.
I picked up the early Explorer intake a few months ago and got it cleaned up and painted.

The injectors I scrounged from my junk drawer, out of a Dodge product. They are 23 lb-hr Siemens units with an ev6 connector. The harness is the original feedback carb harness that mated to a 60 pin Ford ECM. I had to make a few modifications to match the MS 1 ECU, and it's installed with a DIY MS to 60 pin adapter.

The first step was to get the engine to TDC, drain the coolant and remove the HEI and dual plane intake.

I installed the lower with Fel Pro gaskets, ditching the end rail gaskets in favor of a 1/4" silicone bead.

Reworking and cleaning up the wiring harness...

Setting the upper in to place revealed interference with the evaporator plenum. There were many ways to correct this, but since I spent a great deal of time getting the engine in it's current position I decided to mill half an inch off the intake elbow. I would have liked to have taken off more, but the EGR ports were getting thin. I may be able to mill right past the EGR ports if there is still interference under load.

I got it started, waiting on an air filter before the first test drive and tuning session. I predict it will pick up some low end torque and run much cleaner with the EFI.

 

[alwaysFlOoReD]

Definitely keep us updated.

 

[ford4wd08]

Hi all. Due to the price of fuel, I took the time to covert my BII to fuel injection over the past week. Thought I'd share the process (although there are many routes to accomplish this).
I'll miss the simplicity of the HEI and four-barrel, but I'm hoping for a 3-4 MPG bump over the 14 MPG I've been averaging. I plan to build another MS v3.0 and keep that and a spare TFI module in the vehicle for redundancy.
I picked up the early Explorer intake a few months ago and got it cleaned up and painted.
View attachment 73975

View attachment 73976

The injectors I scrounged from my junk drawer, out of a Dodge product. They are 23 lb-hr Siemens units with an ev6 connector. The harness is the original feedback carb harness that mated to a 60 pin Ford ECM. I had to make a few modifications to match the MS 1 ECU, and it's installed with a DIY MS to 60 pin adapter.

The first step was to get the engine to TDC, drain the coolant and remove the HEI and dual plane intake.

View attachment 73977

View attachment 73978

I installed the lower with Fel Pro gaskets, ditching the end rail gaskets in favor of a 1/4" silicone bead.

View attachment 73979

Reworking and cleaning up the wiring harness...

View attachment 73980

Setting the upper in to place revealed interference with the evaporator plenum. There were many ways to correct this, but since I spent a great deal of time getting the engine in it's current position I decided to mill half an inch off the intake elbow. I would have liked to have taken off more, but the EGR ports were getting thin. I may be able to mill right past the EGR ports if there is still interference under load.

View attachment 73982

View attachment 73983

View attachment 73984

I got it started, waiting on an air filter before the first test drive and tuning session. I predict it will pick up some low end torque and run much cleaner with the EFI.

One of my favorite posters on this forum! Love your work man. Keep it up!

 

[Mechrick]

Thank you, I enjoy sharing.

One of the reasons I like HEI is you don't need all this:

The distributor I used came from the long block (1992 Bronco 5.0), which used an external module. Since I had all the parts to complete wiring this way (my '88 460 F250 uses the same module and I had a spare), I went ahead and ran it. The remote-mounted ones are more difficult to wire, but don't suffer heat-related issues like the dizzy-mounted setup. The fuse isn't a fuse, it's my impromptu SPOUT connector.

Air filter and rubber elbow are cheapo Amazon fare, I may change the element or run a pre filter in the dirt. I prefer paper over washable for off road.

-Also need to figure out a heat shield around the filter, so it pulls air from the 5" hole I cut in the inner fender instead of from under hood.

I ordered a small 6 position fuse box to clean up that atrocious positive terminal.

Fuel pump is the in-tank unit left over from the four-cylinder injection. The '85 tanks are the first year that has a standard hole size for both carbed and EFI. There is *no* baffle in the tank though, so running the newer style pump that has it built-in is a must. Fuel lines were made with the Dorman fuel line tool and the old fittings mated to new 3/8" nylon tubing. Fuel filter was ordered for a 2003 Thunderbird (the two-seat Jag version). To the best of my knowledge, it's the only one with a 3/8" nipple in-out. The rest are 3/8" in, 5/16" out.

I've got about 30 minutes seat time tuning with the laptop and it's already way more accurate than the carb could ever hope to be. This engine runs flat top pistons and likes to ping at WOT. With the HEI I could only pull timing, with the MS I can tune right around the ping.

 

[Elutheros]

I am running the MSPNP2 with my 5.0 and M5ODR2 transmission. On good days cruising at 65mph I can barely get 15.5mpg. Pushing 33 inch tires with a 3.73 rear axle ratio could be part of the problem. I don't hold much hope for higher MPG even with my EFI. Nice work converting yours!

 

[Mechrick]

I had two full size Broncos, one with a 5.0/E4OD/31x10.50-15 and the other with a carbed 300 and ZF 5 speed and 33x12.50-15's. Both averaged 16.5 highway. Explorer 5.0's are rated 18 mpg highway. If I can't get 17 or better highway I'll go back to a fullsize.

 

[Shran]

Nice! Curious why you didn't go with a FiTech, Sniper, etc? Seems like the easy button these days for engines with a 4bbl intake.

Kinda here nor there at this point but I believe the upper plenum you used can be rotated 180 degrees so that the inlet is on the driver's side. I have a Crown Vic upper on mine that is rotated that way from the factory and it worked very well for clearance... you might run into your power steering reservoir with the intake tube if you did that though.

FWIW I can average about 14 on the highway with my truck. It is a stock 1989 302 with a 4 speed manual behind it, on 35's, with 4.10 gears. I think a bit more power and a 5 speed in my case would result in even better mileage, it just screams at 70mph.

 

[Mechrick]

Curious why you didn't go with a FiTech, Sniper, etc?

Lawd, no. Then I would have to actually spend money...

I'm not against the throttle body setups that are out there, but in this case I had all the components lying around except the intake. Quick trip to the pick-a-part solved that.

-And, no throttle body setup will be as good as port injection, ever (although they are a step up from carbs).