•  

    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
5
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
71
Reaction score
6
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
71
Reaction score
6
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
 

CORedneck

New member
Joined
May 3, 2021
Messages
5
Reaction score
0
Points
1
Vehicle Year
1985
Vehicle
Ford Bronco II
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, You are a lifesaver. Having fought the problem for days and finally deciding the problem had to be the EEC your advice saved me from the expense of replacing an unneeded EEC. I checked for spark like I should have done in FEB, I discovered I had spark. Then I took a spray bottle and sprayed a little gas past the Throttle body and got it to fire off. I then jumped the fuel pump and it ran as long as I had it jumped. The final result is everything is okay except for a fuel line problem that I will take care of when I get the new parts. In my case the fuel pump was easy to jump by taking a test light and touching it to the fuel pump terminal in the VIP test connector on the power distribution box. The information about how the EEC operated the fuel pump is valuable information. Thank you so much again Uncle Gump.
 

Uncle Gump

Moderator
Forum Moderator
Joined
Mar 4, 2020
Messages
71
Reaction score
6
Points
8
Vehicle Year
2022
Vehicle
Bronco
I guess I'm confused to the lack of root cause. What actually fixed your issue?
 

CORedneck

New member
Joined
May 3, 2021
Messages
5
Reaction score
0
Points
1
Vehicle Year
1985
Vehicle
Ford Bronco II
Taking the time to check for spark and bypassing the fuel pump relay to make sure it was pumping fuel properly fixed the issue. It was my first time dealing with a computerized engine and I ignored the basics of checking for spark and fuel. The information that Uncle Gump provided about how the EEC operated the fuel pump helped me down the right path to success.
 

CORedneck

New member
Joined
May 3, 2021
Messages
5
Reaction score
0
Points
1
Vehicle Year
1985
Vehicle
Ford Bronco II
Still Having Problems with my conversion. If I spray gasoline into the intake the engine will run. Problem now is fuel supply. I have 12.5 volts at the pump, 3 inches of gasoline above the top of the pump and not a speck of dirt or corrosion any where in the tank or on the fuel pickup strainer. The pump spins freely. I am on my second new fuel pump from two different suppliers and can't get more than 8 psi out of the pumps and as soon as I stop the pump the pressure goes to zero. It is possible to have two defective pumps, but very unlikely. I have a third new one coming. The only problem I can see is that because of the shape of the tank the pump sits at a 27 degree angle from vertical. Would that 27 degree angle be causing the problem? When the new pump gets here, could I test it in a bucket of water before I install it to make sure it works correctly? Will the water damage it? Uncle Gump, you have helped me before and I would appreciate your input again. If I could start this project over I would definitely save myself a lot of effort and expense and start with a fuel injected BII instead of a carbureted one.
 

Uncle Gump

Moderator
Forum Moderator
Joined
Mar 4, 2020
Messages
71
Reaction score
6
Points
8
Vehicle Year
2022
Vehicle
Bronco
First off... I wouldn't test a new pump in a bucket of water.

The fuel pressure regulator on the fuel rail is what maintains fuel pressure at the injectors. You have a return type system... fuel will be supplied to the fuel rail and the regulator will allow any excess fuel to circulate back to the tank... after the pressure needs are met for the engine/injectors. The regulator should maintain fuel pressure at the injectors for days once the engine is shut off. If your pressure drops to zero as soon as the pump shuts off... I would suspect the fuel pressure regulator is bad.
 

CORedneck

New member
Joined
May 3, 2021
Messages
5
Reaction score
0
Points
1
Vehicle Year
1985
Vehicle
Ford Bronco II
OK uncle Gump I will keep the new pump out of the water. I am checking the pressure at the pump itself with a fuel pressure gauge and I have only had a maximum of 8 psi at the pump itself. As soon as I cut the power at the pump the gasoline drains back into the tank and pressure falls to zero. When I get my third new pump tomorrow, I will hold it vertically in the tank with at least 3" of fuel over the pump and see what happens when I run it. I have 12.5 volts at the pump.
 

Uncle Gump

Moderator
Forum Moderator
Joined
Mar 4, 2020
Messages
71
Reaction score
6
Points
8
Vehicle Year
2022
Vehicle
Bronco
You really need to check your fuel pressure after the pressure regulator. Checking pressure before it is pointless. Checking volume is OK... but it won't build pressure with nothing to pump against.
 

Top