4.0 swap

[Leland]

I just completed a 4.0 swap on my 89 Bronco 2, the donor was a 94 Explorer. The issue I am having is after I drive for a while and shut it off it won't start right away, I have to let it sit for a while 15-20 minutes. It doesn't overheat, miss or anything else it runs great. Anyone have a clue?

 

[RonD]

Welcome to TRS

Nothing comes to mind right off

But you could find out if it was spark or fuel causing the no start using 50/50 test
After engine is warmed up and doesn't start
Pop the hood
pull off the power brake booster's vacuum hose, from the booster end, hold it up
Spray Quick Start(ether) or gasoline into the hose so it goes into the intake
Put hose back on and try to start engine
If it starts and dies fuel system is the problem
If it doesn't fire then spark is the problem
50/50


1994 4.0l used EDIS-6 module for spark it was usually located on the front side of the Rad support to keep it cool, i.e. out of engine bay and in cooler air.
Where is yours located?

You don't mention poor MPG which would be a sign of leaking injector or FPR(fuel pressure regulator)
This can cause Flooded Engine issue on warm start.

CKP(crank position) sensor is the main sensor for the system, only sensor that can cause a no start, but these rarely fail, not never, just rarely
CKP sensor generates its own AC voltage as crank spins next to it, it isn't a high voltage, so can be effected by heated wires.
CKP is located at about 10:00 on the front of the engine next to crank pulley, its wires run up the front of the engine around water pump and into the main harness on lower intake.
Have a look at that section of wire, make sure it hasn't been damaged and insulation is still intact

There was a member here that had similar issue with 2.9l using TFI ignition, so not related at all to your type of system, but...........
He had an interesting approach to find the problem............ICE
Used a bag of ice to cool down TFI module or coil or ?? to see if engine would restart faster in one of the components was cooled down

 

[Rustbucket350]

Might want to carry a test kit with you and check the fuel pressure when it won't start.

 

[BLOODBANE]

Might want to carry a test kit with you and check the fuel pressure when it won't start.

My 94 Explorer was having issues like this as well. It would run fine and out of the blue it would just crank (no start). I ended up taking it to FORD and they had it about 2 weeks and came up with bad fuel pump (starting to go). This is just my experience and not necessarily what your facing.

 

[richard booth]

Had a similar issue that turned out being the inertia switch.

 

[broncobuckinaround]

just did a 4.0 swap a year ago and was very pleased. still running strong.

as posted already i would check fuel pressure. then check spark. if it is an orange color it is weak. needs to be bright blue.

if may be ground related. easy to miss in doing a swap.

check for codes as well

 

[dangerbird92]

I just completed a 4.0 swap on my 89 Bronco 2, the donor was a 94 Explorer. The issue I am having is after I drive for a while and shut it off it won't start right away, I have to let it sit for a while 15-20 minutes. It doesn't overheat, miss or anything else it runs great. Anyone have a clue?

Any chance you can give me some advice on how you did the wiring the write up doesn't give a lot of details 89 bronco ii and I have a 4.0 and wiring from a 94 explorer

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[BlackBII]

Any chance you can give me some advice on how you did the wiring the write up doesn't give a lot of details 89 bronco ii and I have a 4.0 and wiring from a 94 explorer

Sent from my SAMSUNG-SM-G891A using Tapatalk

What specifically do you have questions on? You basically need to swap the entire engine bay harness along with the computer. If you also swap the dashboard it makes it much easier.

You'll likely have to put some extra time into the harnesses that go to the rear of the truck; tail lights, fuel pump, etc.

 

[dangerbird92]

What specifically do you have questions on? You basically need to swap the entire engine bay harness along with the computer. If you also swap the dashboard it makes it much easier.

You'll likely have to put some extra time into the harnesses that go to the rear of the truck; tail lights, fuel pump, etc.

On the write up it says I have to cut and splice wires in the driver's side fender I pretty much got that other than a red wire and a red with blue stripe than it says I have to cut the power distribution box and replace it with the explorer but it is unclear why

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