Question regarding 95 /96 4.0L OHV Wiring Harness/PCM Pinout differences

[Tom Graham]

Hello!

I'm swapping the 4.0L OHV engine in my 95 Explorer for a 4.0L OHV engine out of a 96 year model.
The engines appear identical except for the camshaft position sensor, the connector shapes on a few things like vaccum selenoid, coil pack, etc..
I want to use the wire harness that came with the 96 engine, as it is in better shape than the one in the 95.
Both wire harnesses have the same 60 pin PCM connectors.
There are a few slight differences in some of the other connectors.
Mainly the two connectors that route to the transmission.
One is grey & round with a second black square connector on the 95 harness, where both are square (black & grey) on the 96 harness.
I cannot find a 95/96 4.0L OHV PCM Pinout diagram to compare the two.
I plan on cutting the needed grey connector off my 95 harness and splicing it to the 96 harness...only there are two extra wires on the 96 harness' grey connector that are not on the 95.
I really don't want to take all the sensors off the old engine or buy new ones just to use the old harness.
My sensors & selenoids are fine on the 96 engine (I believe).
The newer 96 engine has a complete harness with matching sensors/selenoids and it would be great if I could keep it and use it with the 95 PCM.
I bought this 96 engine used and it did not come with a mathing PCM.
I believe I have OBD 1 & OBD2. I have the OBD 1 connector under the hood near the fuse box and I have the OBD2 connector under the steering wheel.
Can someone please tell me if the newer 96 wire harness will work with the 95 PCM or know the differences between the 95 & 96 PCM Pinout?
A 95 & 96 PCM Pinout diagram would be very helpful also.

Thanks in advance.

 

[410Fortune]

Use your 95 harness and 95 engine components

The 96 is OBD II and uses a 5r55e transmission
your 95 is OBDI and uses a 4r55e
they are different transmissions

The cam sensor must match the computer so you must put your 95 cam sensor into the 96 engine

If you want to use the 96 engine wiring harness you would need the 96 engine PCM (Computer),
1995 was the first year of the Gen II explorer and it was an odd ball year for many parts

 

[Tom Graham]

Thanks for your reply.
I figured this would be the case.
This does however raise a few new questions.

• These two synchronizers appear completely different. Plus, the wire connector on the 95 Synchronizer Cam Sensor is broken. The harness connectors are slightly different but both have three wires. Could I just cut the cam sensor connector off the 96 harness and splice it to the 96?

• Why do I have OBDII connector under the steering wheel and OBD1 under the hood?

• Why are both PCM wire connectors 60 pin?

• the oil, coolant & crankshaft sensors appear identical. I am assuming I can leave those original sensors in the 96 engine and just swap out the throttle assembly with TPS, vacuum selenoid, EGR selenoid & coil pack?

• I was really hoping to avoid pulling the synchronizer. Will this affect my PCM timing the fuel injection? Any pitfalls there?
Will I need to reset the PCM by pulling the SPOUT connector?
I've never done this part before and really appreciate any guidance.

Thanks again

 

[Tom Graham]

UPDATE:

I took your advice.
I swapped the following sensors/selenoids etc. from the 95 engine to the 96 in order to keep the 95 harness & PCM

• Crankshaft Position Sensor
• Synchronizer & Cam Position Sensor
• 2 Vaccum Selenoids
• EGR Selenoid
• Throttle Body with TPS
• 2 Coolant Temp Sensors
• Oil pressure sensor
• Ignition Coil Pack

Now I have a few new questions.

1. Does the synchronizer only drop in one way? Or will it also go all the way in at 180°?
I am only able to get it in one way.

2. I rotated the harmonic balancer on the 96 engine so that it matches the exact point where the 95 engine was when I last ran it.

In other words, the pointer on the Crank Position Sensor is pointing to the same location on the 96 harmonic balancer, as it was on the 95.
Assuming both engines to be matched now on the crank & cam positions, will dropping in the 95 synchronizer into the 96 block also be matched, assuming it only goes in one way?

What I am getting at is, matching both engines should be all that is needed to plug & play, right?

Or will there be a timing adjustment after it is bolted in & ready to fire up?

Pulling that synchronizer back out, once the engine is installed, is not something I want to have to do.
I have this engine out & on a stand. It would be great to get it set up to plug & play as much as possible before install.

I repaired the damaged 95 Cam Position Sensor on the synchronizer. Was just the plastic part of the wire connector at the housing was cracked enough for the connector to move around. The three wires were still intact inside.
I epoxied the plastic back to the synchronizer base. Now it is fine. No play.
I think it got bumped on the firewall when I hoisted the engine out.

I am just concerned that the timing isn't going to be right, or injectors will be spraying on the wrong stroke, spark plugs firing out of order, etc...

Any advice would be appreciated.

Thanks.

 

[410Fortune]

You need to align the 95 camshaft synchronizer now while the engine is out, or at least before you install the upper intake plenum

Does your 1995 camshaft sensor have a glass window on it?
If not you may need an alignment tool



To align cam synchro:
You will need to bring cyl #1 to top dead center on compression stroke, then install the 95 synchro with the pointer inside the looking glass.Your crank balancer should then have the 0 degree mark line up with the pointer on the crank sensor.
Cyl #1 is the front cyl on pass side on your engine
To find TDC on compression stroke
remove all 6 spark plugs
place a wet finger over the spark plug hole on cyl 1.
Turn the engine over, clockwise
You will feel air rush past your finger, this is compression stroke.
Take flashlight and as you turn engine slowly watch the piston come to the top. Some people will stick a screwdriver in and watch it rise, I use a flashlight on the OHV
As soon as the cylinder stops and starts to drop, that is TDC
Now you can drop in your cam synchro pointing in the correct direction on the engine
with the flag pointing in the correct spot in your glass window / vision panel
(or the alignment tool installed)

This aligns the camshaft sensor to the engine, there is no other timing to perform after this

The crank sensor simply bolts onto the engine and the crankshaft balancer you installed is keyed and can only go on the engine in one position.
Let me look up instructions for the 95 synchro it was covered here recently

The ohv 4.0L engine was made from 90-2000 in Rangers, Explorers, Aerostar and Mazda B4000
The early ones 90-92 had head cracking issues and some oiling issues to the valve train. Still very good engines. In 93 they were upgraded slightly and then again in 95. In 95 the heads were improved quite a bit. In 96 they were finally full OBD II electronics, and in 98 they were upgraded again and used a 8 bolt crank.
When replacing your current engine with a later model, you want to re use the long block, which is the block and heads....keep your trucks wiring and sensors, and never throw anything out until the swap is done.
I park both engines next to each other in the shop, strip what I need from the old and clean/install it on the new, good time to replace any gaskets and do a full tune up. Fix any aging vacuum hoses, etc.
95 is a good year, I know of a 95 Eddie Bauer with over 380K miles on the stock engine, still passes emissions.........FYI in 95 the 4.0L pushrod was the only available engine

Good job so far!

 

[410Fortune]

This should cover the install instructions for your 95 synchronizer

Cam Synchro

1995 is an odd year for the OHV, but a good one!

 

[Tom Graham]

Thanks so much!

I got the 96 engine real cheap ($175) plus another $75 for the guy to deliver it to me in Nashville from Illinois.
So it was already pulled when I bought it.
The engine is reported to have 150k miles.
I popped off the oil pan & valve covers to find a like new appearance on all the moving parts.
The bearings, rocker shafts, valve springs, crank etc...all had a beautiful golden color and very little carbon build up or wear.
The guy had video of the engine running before he pulled it. He had bought the Explorer wrecked for the transmission. His son needed that for his Ranger.
He kept the motor in his shop for a few months till I bought it.
Very low risk at that price, since I could make most of my money back simply scrapping it.
But I believe this to be a good engine.
I put it on an engine stand and so far I have replaced the Rear Main Seal, new Motor Craft Spark Plugs, New Serpentine Belt, Oil Pan Gasket, Valve Cover Gaskets & PCV Valve.
I took your advice today and swapped out the remaining 95 sensors to the 96 block.

Here are some before and after photos of the process. I cleaned every inch of this motor. Painted & very close to completion.

I do have a sight glass on the 95 synchronizer. I'm not sure what pointer you are referring to though.

I will try to research this a bit more.

I am mainly concerned with how the PCM determines the correct time to spray injectors if It still thinks the engine is set to the position it was when I pulled it.
If I stab this 96 motor with #1 at TDC, how does the PCM know?
I know on older OBD1 Ford motors (like the 88 460 7.5L) the SPOUT connector has to be pulled to reset the PCM.
I guess I am over-complicating this.

Anyway, I have the 95 sensors all swapped over to the 96 block and will keep the 95 harness going forward.

I'm still not confident in this synchronizer situation but I appreciate the help.

I may need to touch base with you this weekend to make sure I get this sight glass thing right.

Thanks again for your time and input.

Happy Thanksgiving!

 

[gmanpaint]

95 is actually an obd1.5 because of the trans, and a couple other items.

The port under the dash is a dummy. Ford started obd2 with the 95 ranger, and 96 with the explorer when it became mandated. The port was already configured for the same engine used in the ranger, and they just used the same harness style in both, knowing it would be used in production later that same year. Still doesn't make a lot of sense, as the two systems used diff wire counts and connectors. ******* year is what I call it.

There are a few features in the 95 that also make it obd1.5, like the intro of the gem, and alarm. Like 410 said, it's an oddball year, with stand alone features, not found on others, but does share some items with the 96. They have the same trans. 97 is when the 5 speed was used. Yours might have been a late year model with the 97, and why the harness is different. Hard to say.

96 is a 120 pin, so not sure how yours is a 60 pin. Something doesn't add up there.

95 is when they jumped to a 3g 130amp alternator, and a few other electrical upgrades. It was either a test year, for the switch to the obd2, or Ford had a group of wacked engineers scrambling to match the already upgraded ranger in full production, but fell short on a deadline. Lol

 

[974X4BLACKSPORT]

Nice tire.

 

[Tom Graham]

Nice tire.

Lololol...I don't know how that tire got uploaded. When I realized It was there, I attempted to edit but it won't let me delete the silly thing

 

[410Fortune]

Good info there Gmanpaint!!

Follow the link I provided for the camshaft pos sensor installation it will show you what pointer I am talking about

A 96 4.0L with only 150K on it is awesome, especially after you have completely refreshed it with new gaskets and tune up parts. You keep the oil clean and the engine cool and you will see 350K miles from this engine no problem........

It looks GREAT!! Nicely done.
Did you polish the oil filter mount? Holy heck man you must have ADD like me!!!

 

[Tom Graham]

Yes I have an affliction lolol.

But as for the pointer on the CPS...
The image links are broken and I cannot view those.

 

[410Fortune]

These pics? I can host them and upload them here



This shows the angle of the cam synchro on a 98+ ohv 4.0L, should be similar to yours when seated properly

Here are some interesting instructions that work for all years
These instructions although handy, can complicate things.
All you need to do is have the engine at TDC then drop in the new Synchro with the pointer in the correct spot and the body of the sensor at 60 degrees and you are done:

 

[Tom Graham]

Perfect. Thank you. I can see the pics now.
I will give this a whirl.

PS anyone have any advice on removing the fan & clutch? The manual says I need a special tool. I'm about to carefully & surgically remove it with a large hammer if I can't figure out something. I want to clean and polish/paint front engine area (timing cover/ water pump/ pulleys etc...)
This fan is really in my way...

 

[gmanpaint]

Best just to go get the $20 fan wrench set. One holds the water pump, and the other turns the fan from behind.

Most auto parts stores carry them.

 

[Tom Graham]

Hey I'm back with a new round of questions.
I hope I'm not being too much trouble.
Here is where I am:

• I am to a point where I have #1 Piston at TDC on compression stroke.

• The needle on the Crank Position Sensor is pointed directly at the 0° mark on the harmonic balancer pulley. (See image)

• I followed the directions precisely and dropped in the synchronizer. The Haynes manual says to "align the trailing edge of the sensor vane with the short mark at the left side of the sensor window."
I have 2 marks in that window. One is short and is on the left side of the window. (See image)

• The problem I am having now is, there is not enough clearance to turn the synchronizer body enough for the leading edge if the vane to touch that short mark.
(See image)

What am I doing wrong? I cannot proceed until I have this worked out right.

I appreciate the assistance.

 

[roscoe 0202]

the drive shaft to the cmp has splines pull the sensor up so splines are out of shaft and rotate sensor drop down on splines you should be able to rotate it where it needs to be
roscoe

 

[Tom Graham]

UPDATE:

Thanks Roscoe!

The shaft in the bottom of the bore hole demonstrated some play (wobble) and was falling to one side and not sliding inside the bottom of the synchronizer shaft hole. It was smacking the bottom edge of the synchronizer & not stabbing in it.

I rotated the engine on the stand slightly to the left until the shaft in the bore hole stayed stationary in the center and BAM! Synchronizer went right in!

Now it looks like this.

The Haynes manual states

 

[Tom Graham]

Sorry. Hit the wrong button.
Picking up where I left off:

The Haynes Manual states to put the leading edge of the vane on the small mark on the left of the sight glass, then insert the synchronizer.

Once it dropped in, the leading edge of the vane is now closely aligned with the long mark near the center of the sightglass.

The synchronizer is now aligned very close to the 0° center engine line.

I still have #1 piston at TDC (0° mark on Harmonic Balance Pulley) and is on compression stroke.

Do I call this a successful synchronizer installation?

Here is a wider shot of the synchronizer alignment near the 0° center engine line.

 

[gmanpaint]

I think your good to go there. If it was a tooth off, it would be around 15* off. Might want to wait for others to confirm, just to make sure.