•  

    Click HERE to join our forum and participate in the discussions.

     

HELP Can't get my BII conversion to start.


CORedneck

New member
Joined
May 3, 2021
Messages
1
Reaction score
0
Points
1
Vehicle Year
1985
Vehicle
Ford Bronco II
Did a 92 Ranger 4.0 swap into my 85 BII. The Ranger is my own and it ran well before I started my project. I installed all the wiring harness from my 92 Ranger into the BII except for the light harness which I kept in the BII. The headlights, turn signals and horn even works. The starter works off the ignition switch. I connected the red/green wires together like in the excellent tech library article. Everything went well until I tried to start it. There is a relay that kicks on and the fuel pump runs for maybe a half second and then everything kicks back off. The fuses in the power distribution box are all good except the one for the alternator is not getting power to it. I ran all of the Ranger harness to the engine and over to the drivers side and retained the BII plugs to splice into. Any help anyone can give me to find the problem would be greatly appreciated. I used an old mechanics trick when I put the engine in. You take some spare stock rims without tires and put them on the front axle lowering the front several inches and making it easier to clear the front radiator support.
 


Uncle Gump

Moderator
Forum Moderator
Joined
Mar 4, 2020
Messages
63
Reaction score
3
Points
8
Vehicle Year
2022
Vehicle
Bronco
So the fuel pump relay turning ON with a key ON cycle and back OFF is normal. The relay should then turn ON again once the ECM sees engine RPMs over 400 RPM.

What I would try is to jump the fuel pump relay and see if the engine will start that way.

I assume you checked for spark and you have it.
 

Uncle Gump

Moderator
Forum Moderator
Joined
Mar 4, 2020
Messages
63
Reaction score
3
Points
8
Vehicle Year
2022
Vehicle
Bronco
Here is a cut and paste from a post in another forum that may help get you going....

Do 50/50 test anytime you have a crank but No Start............on ANY engine, lawn mower to V12

50/50 test
spray fuel into the engine, i.e. gasoline, ether, carb cleaner, ect.............

Try to start
If it starts, runs and dies then you have, good/timed spark, but no fuel delivery
If it doesn't fire or start then you have no spark
50/50, instant results on where to look

The ONLY sensor that can cause a No Start is the crank sensor, just FYI, and it causes No Spark


When you turn on the key the CEL(check engine light) will come on, it means computer is powered up
When you activate starter motor the CEL should go OFF, that means Crank Sensor is working, computer is getting a timing pulse

There is one other sensor that can fail in an extremely RARE way, the throttle position sensor(TPS)
Unplug the TPS 3 wire connector and see if engine starts and runs, if TPS shorts fuel injectors are shut off

New fuel pump means NEVER TESTED fuel pump, unless its a Motorcraft, and they are way too expensive, lol
So "new part" doesn't mean "working part"
If possible test fuel pressure


I just had to change the capacitors in my 1994 computer, after 20+ years they leak and fail, under $5 to fix
So if you have odd issue it worth a look versus just randomly replacing parts that can'[t fix a computer issue
And it's free to have a look
You can see the 3 blue capacitors in this picture: http://www.auto-diagnostics.info/ford_eec_iv
 

Top