5.0 SEFI install in a Bronco - by Brian Wickert

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5.0 SEFI install in a Bronco - by Brian Wickert

Post by johnl » Sat Sep 18, 2004 12:42 pm

SEFI Install in a 70' Bronco, plus other misc info passed on to me from the Broncofix and Early Bronco Mailing List.


OK it needs a little organizing and cleaning up, but doesnt it still look PRETTY!


I added sefi to my bronco because I was having alot of problems with the 4-barrel flooding in exteme angles, when you least want your vehicle to die. I enjoy the excitement of 4wheeling, but that was a little too much! Sure you might gain a couple of miles per gallon, but it will take a lifetime to make up for the cost of installation. And maybe the motor will last longer, because of proper fuel mixture at all altitudes. Then ther is the Major WOW factor, thats a biggie.

In the begining it may seem over whelming, but I assure you it's pretty easy. Not to mention it's a great learning experience. Always pays to know your vehicle! I should mention that I don't have a body lift.

WARNING! The weak of heart, should not look at this next photo!


To start off with, I should let you know where I'm coming from. I had a 95 mustang gt 5.0L HO motor already installed. It was a crate motor that I had ordered from Ford Motor Sport 2.5 years earlier, now I just wanted to add SEFI.

For those of you that want to add sefi to your old 302; FMS also used to sell a engine harness for the 302 firing order, but they discontinued it because the O2 sensors were reading the wrong cylinders and leaning and riching at the wrong locations. Several people have said this was a bunch of smoke, and just changed the locations of the injector pins at the plug. And have had no problems.

Remember that I have a smog exempt vehicle!

Lets get busy!


I purchased my upper stuff from corral.net, but I wouldn't recommend it unless that is all you need! Heres the problem; The mustang guy will need all the little fittings, brackets, fuel rail, distributor, and cables. These parts will ADD UP bigtime! You are really better off paying $650 for the high mileage motor and everything to run it! Prices seem to run as high as $1300 depending on your area. Just finding the 89-93 mustang, that hasnt been stripped, will be the fun part. Call around, and insist on doing most the removal yourself! This will be a good learning experience, plus you'll have a reference to go off of when you install.

If you elect to install the 5.0L HO motor here are some "need to knows":

1. The Mustang Flexplate from the automatic will work, if you have the torque converter that measures 11 7/16" measured at the bolt holes diagonally. These were in the 76-77 models, but many of the earlier ones have been upgraded from the 10.5" pattern. It's a crap shoot here! You have to have the 50 ounce imbalanced flywheel/flexplate and Dampner. If you decide to use your v-belt setup, just change everything from the timing cover forward, and buy a 3 bolt dampner from TOTAL PERFORMANCE (810)468-3673 for $160 delivered. The 5.0L Mustang bell housing doesnt have a bolt hole for the clutch lever, but there is a simple solution. I'm sorry I dont have that information at this time.

2. Many are using the short Mustang headers, but the clearance on the passenger side is very tight. Also others have reported that the driverside interfers with the clutch linkage???


My List:


Upper&lower stock mustang intake with 19lb injectors, EGR spacer, Throttle body(Idle speed control & throttle position sensor), & MAF. Plus the guy sent me the rubber tubing T.B.-MAF, & MAF-airbox. $225 plus $50shipping. Great experience! COD ONLY! Great resource for 5.0L info.

http://www.allmustang.com junkyard in AZ (800)454-8387

Complete EEC-IV Dist., coil & rubber boot, also sent wires.---$70. Fuel rails & regulator w/ some line---$50. Throttle cable & bracket---$35. Coolant tubes---$15. PCV, T for upper intake PCV, & vacuum connector that screws into upper intake---$20. A9P computer---$100. Freight---$25. Dealt with Tom(sales), but talk to the tech(Chris) that pulls the stuff also. What Tom writes may not be exactly what Chris pulls!

Scottsdale vehicle concepts AZ (602)998-8885

M-12071-c302 EFI harness---$316.25 (This is not needed if you dont mind purchasing a HELM wiring manual, and doing a little tracing. Also you will have to judge the quality of the used wiring available. DON'T PAY THE $700-$900 SOME OF THE WIRING PLACES ARE ASKING FOR THEIR HARNESS!) M-12071-D302 Sensor/Relay package---$128. M12071-E302 Engine harness---$126.90. Freight---$7.00 Had everything in stock!

Local Ford Dealer

e3az9e731a Vehicle speed sensor(Any ford transmission)---$25.13. These guys were useless w/o part #'s or specific application info.. Me and other's have run with/without the VSS and we can't tell the difference. I would only bother with it if you have cruise control!


Cable ties, 14 & 18 gauge wire, New V-belt, 10071Heater hose---$10.49. 9812Heater hose---$13.69. Ford fuel filter---$10. PCV filter---$4.29. Couple of plugs with pipe threads for intake holes not used. Fittings for the 5/16" fuel rails to barbs. 24' of steel tubing 3/8". Fuel injection rubber tubing 3/8". 4' of vacuum hose. ST404 Starter solenoid w/ diode---$14.--. If you talk to the right guy, they can really help also.


Gaskets: 8384432--$3.20, 8384432--$5.32. Valve cover gasket--$12.19. Fuel injection hose clamps(These are really good)---$2.49. Borg-Warner fuel pump(86' F250 external 5.0L pump)---$99.99,price checked with Autozone -$34.00 = $65.99 + tax($70.77). Some shops wont price check any longer! 8>( Don't expect much from these guys.


Muffler shop: weld O2 bosses onto vehicle---$36.44. Speedometer cable, Summit racing: K&N air filter RU-3130 7" conical---$34.45 delivered. Plus I sold my Duraspark stuff, Holley 600cfm, & FMS intake at the CORRAL for $300. The cannister purge system, and solenoid are not necessary in non-smog applications. Just thread the hole in the intake, and install a plug.

Lets start with the fuel system:

I added a 23gal. tank with a extra 3/8 line for the pickup. I wanted the pickup back by the baffle, so I drilled a hole in the front of the tank, just right of the original, at the side. I ran a piece of bent 3/8 brake line down the side and curved towards the middle. My local radiator shop welded it in for free! Just the one weld at the front. I did the external EFI fuel pump from a 86 F250, and I ran 3/8 steel tubing up and back, it wasn't hard. I don't know if I like it, I'll have to put rubber between pump/line. I think I should of just ran rubber the hole way. Well, this will give me something to do next year. Remember you only need the expensive high pressure rubber efi line between the pump and the fuel rails, the rest can be regular fuel line. Here's how it turned out:


The fuel pump bracket, is my old coil bracket. Make sure you keep the lines away from any heat! The rubber lines where slid over the pump and filter fittings, and clamped. I connected the other end of the line to the fuel rail with compression fittings and a little tephlon tape:



Remove the Duraspark ignition, and Carb./intake. Remove throttle linkage, and valve covers. Put lower mustang intake on, don't forget the new gaskets. Install injectors, engine harness, coolant tubes, rails, sensors (ECT & ACT), water temp for gauge, plug(at rear on drivers side), and nipple(at rear on pass. side, for EGR). Installed a 195 thermostat. Easiest to install this stuff with intake off the vehicle. The water hoses for the coolant tubes were; one hose was 3/4" with 90degree to 5/8", This was hooked to the heater valve with another piece of 5/8" to heater. The other hose was just a 5/8" with a 90degree bend, It was hooked to upper tube and then ran to heater.

Pulled out the O2 sensor harness, and guess what there were two. My lucky day, two for the price of one? NOPE, One (BA) is for automatics, Second(AA) is for Manuals. I have no idea why, but they are different! I hooked the harness to the installed O2 sensors, perfect! I am mounting the O2 harness on the firewall as recommended.

Hooked up a jumper from the battery to the fuel pump, WHAT A SWEET PUUURRR! Hooked up pressure gauge to the schrader valve, 42PSI, I'm a happy man! One little leak, but it was a simple fix. I strongly recommend the fuel injection clamps, the regular clamps seem to cut into the hose. One spot where I slipped 3" of rubber hose over 3/8"steel line and clamped, I had visions of this exploding apart, what a imagination. I worry to much!

The computer harness was prepared earlier on the living room floor. All the tape was removed from the brand new harness, this is ugly! The only thing I left on the drivers side fender was the coil, test plugs(2), and connector 31(FMS#). Connector 31 was removed, 8 wires were present. Some of the wire colors even matched the Bronco colors. The rest of the harness was routed over the firewall. Plugged in the black/white connectors to the engine harness and stuffed them behind the intake with everything else!

I removed the gas pedal and heated it up at the "dog leg", twisted it 90degrees so the ball on the end was facing back of vehicle. Make sure the ball is still centered with opening to the firewall. Ground off one side of ball and punched it out. Drilled it 11/32, hack sawed a notch from top down to hole. Chiseled the notch open gently, to allow throttle cable to slip through and snap in the plastic retainer into place, just like it was OEM. Bolted the cable right to the pedal assembly!


Mounted fuel pump block off plate, sealed off passenger kick panel with piece of aluminum, mounted computer onto kick panel with metal straps and two sided foam tape for a little cushion. Cut hole in firewall 2 7/8"x1 1/4" inserted eec-iv plug and wrestled the groumet into place. Replaced the old starter selonoid with the NAPA ST404 with diode.


CRANK&RUN source was located at the ignition. It is simply a wire that has electricity when the key is in the run, and the crank positions. It is recommended to use a relay that is triggered by this wire. I have been running mine directly off the ignition with no problems; Check engine light, Red/green(ignition), and the Gray/yellow(fuel relay) were all connected to the Green/red 70' Bronco wire off the ignition. FMS says to hook the Gray/yellow to a "run only" source, but mine has worked fine for a year now.

CRANK Red/light blue wire(TFI), and White/purple(Self test input). These were connected to the "I" terminal at starter solenoid.

Here's the details: (From the FMS wiring instructions)


* EGR vacuum sensor was connected to harness and receives vacuum from manifold, with another vacuum line running to the EGR valve.
* TAB & TAD were connected to harness to maintain "closed loop". They received no vacuum.
* AC pressure switch plug was connected to post on AC cannister.
* Plugged MAF connector into MAF.
* Connected O2 harness.
* Plugged relay's into Fuel pump switch and Wide open throttle.
* Power wires Blue & Black connected to starter solenoid(ST404 at NAPA) positive.
* Hooked main ground(Black/white) to battery post neg..
* AC clutch connector, Black/yellow was connected to AC clutch.


* Plug in coil, mounted on fender.
* BROWN PLUG was removed so the RED/light blue & White/purple could be connected to "Crank".
* The Red/green to "Crank & Run".
* White/red & Red/white connected to oil pressure & water temp gauges(These are not part of the computer system).
* Tan/yellow connected to the tachometer.
* Gray/pink & Purple/yellow are for the neutral safety switch on manual transmissions.


* GREEN PLUG near the computer was removed:
* Gray/yellow(fuel pump relay) goes to "RUN".
* Purple gets the power from AC thermostat(old wire that went to AC clutch).
* Dark GREEN/yellow to fuel pump positive. The neg. fuel pump connection was grounded to frame.
* Pink/orange to VSS(-) and ground. Green/black to VSS(+). VSS(any FORD) #E3AZ-9E731-A $24.77. New speedometer cable $30.
* Pink/green to a "check engine light", with other side connected to "Crank & Run".


* BP sensor was connected and mounted to firewall. (NO VACUUM!)
* Dist. and Engine harness connected.
* GREEN PLUG near the computer was removed:
* Gray/yellow(fuel pump relay) goes to "RUN".
* Purple gets the power from AC thermostat(old wire that went to AC clutch).
* Dark GREEN/yellow to fuel pump positive. The neg. fuel pump connection was grounded to frame.
* Pink/orange to VSS(-) and ground. Green/black to VSS(+). VSS(any FORD) #E3AZ-9E731-A $24.77. New speedometer cable $30.
* Pink/green to a "check engine light", with other side connected to "Crank & Run".


* The upper intake was mounted, wish I had plugged off the EGR since this adds alot of heat to the intake.
* EGR spacer with water supply.
* Throttle body mounted.
* The original rubber tubing that connected the MAF to the T.B. was partially used. I just cut off the elbow and used it to point the MAF towards the fender and down, since I have no lift.
* Connected the 7" conical K&N filter and everything clears.
* I should mention that I have a hood bubble. Some have mention slight rubbing, depending on how much the body bushings have been crushed over the years.
* Connected throttle cable and the kick down cable(Simpson--lockar kickdown cable).


* I have also set the timing to 12degrees. Set the idle at 750-800rpm(Auto).
* Adjusted the TPS on the throttle body to .980volts, by rotating the TPS clockwise. Voltage was measured at green & black wires on TPS, while ignition is on, but not running.

Thats all for now! Brian Wickert...contact at bwickert@cnetech.com

Bfix "What's a Bronco?"
Bfix "What's a Bronco?"
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Is there an easier way to get FI ?

Post by mybronco69&74 » Wed May 27, 2015 12:12 pm

I have two project EB's, a 69 and a 74, Im working on the 74 presently it is an automatic/302 and it probably needs the motor redone, I was thinking either throttle body efi, or a mustang motor with efi, just want to do it as easy and less costly as possible, otherwise I will just suffer with the carb for a while, opinions on ease and cost needed.

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