The old 93 is starting to get a little tired and a friend happens to have a low miles 2.5 he pulled out of his 98 regular cab after he was rear ended. I know this gets asked often but I am having a hard time finding clear answers.

The 93 is clearly OBD-1 and the 2.5 is clearly OBD-2 so this would not be a direct swap of course. However since then locks are basicly the same and the heads are interchangeable is it possible just to swap the OBD-1 intake and exhaust manifolds over to the 2.5 to make it run? I have also seen something online about the crank sensor being different on the 2.5 but have no idea if you could simply use the 2.3 sensor on the 2.5 block in the intended OBD-1 location.

I really don't want to spend $2000 on rebuilding my current 2.3 if I can make the 2.5 work for less.

 

Won't be an easy swap.

Not OBD issue specifically

Your Pre-1995 engine used a Hall effect Crank sensor, 1995 and up used VR(variable reluctance) Crank sensor.
There is no "wiring" change or electronic device that can convert this.

If you had a 1995 Ranger then you could just swap it out and change intakes, still have to do that regardless of OBD 1 or 2

You would have the same problem swapping in a '95-'97 2.3l into your '93

Image of hall effect crank sensor here: http://i28.photobucket.com/albums/c2...0821111337.jpg


Now the 2.3l and 2.5l are the same engine, just different crank and longer connecting rods.
So you MAY be able to pull off front engine cover on both and put the '93 hall effect sensor and cover on the 2.5l.
Never done it so can't say if crank will work with older front cover.

Front cover is the part behind the timing belt

 

That's my main concern. Ford did delete the hole for the dizy on the latter blocks. So the question is if the mounting for the two front engine covers are the same.

in addition I assumed I would need to swap all the sensors over off of the OBD-1 2.3L since they are slightly different.

The 2.5 head is a lot different then the early 2.3 heads. The roller cam is a nice advantage on the newer 2.3/2.5 engines and from what I understand the OBD-1 ECU is capable of of compensating for it.

 

Yes, that would be the question, if you can swap front covers.
The pre-'95 Crank(CKP) sensor speaks French, and your ICM(ignition module) understands French, and your '93 computer speaks French with the ICM

In 1995 the Crank sensor switched to Italian, and ICM was moved into computer which is also speaking Italian now.
And there is no translation possible between the two, which is where the language comparison falls short, lol.
You need to mount the French CKP sensor on the Italian Motor

There really are not many "sensors" to deal with.
On engine block there are two SENDERS, oil pressure and coolant temp for dash gauge.
And one sensors, the ECT(engine coolant temp) sensor used only by a fuel injection computer, drivers side towards the front under intake on a '93
It may be on heater hose on 2.5l
But same sensor, '93 computer will understand 2.5l ECT sensor

If you have a CPS(cam position sensor) then it should be the same as 2.5l, VR sensor

The intake will have the TPS(throttle position sensor), and MAYBE the IAT(intake air temp) sensor, in '93 that sensor could be in the Air Filter box

And thats it.

Intake will have the fuel injectors and return fuel line used in '93, which 2.5l won't have, which is the main reason to change intake.
Also IAC Valve
So swapping intakes is done to match wiring for injectors and ICM, and fuel system more than OBD issues

But the BIG DEAL is can you use the '93 CKP sensor on the 2.5l engine

 

That seems to be the only real obstical is dealing with the CKP issue. I have been trying to bring up images of both the Pre 95 2.3 and 2.5 front engine covers to see if there is a clear difference.

Since the fuel injected 2.3/2.5s cranks are interchangeable I don't for see any issue with crank interference. It's really a matter of if the 2.3 front engine cover will mount to the 2.5 block and allow for the correct placement of the crank sensor.

 

Yup, that's the only issue

 

Confirmed you CAN put a newer 2.5 in where a 2.3 was, remove the hall effect sensor, align very very carefully on the new block using the 2.3 harmonic balancer, then drill and tap holes in the block (much easier with the oil pan removed, so you can clean up any drill debris).

One thing to note: the rear part of the 2.5 timing cover will need to be notched, similar to the 2.3, when you have the 2 side by side you'll see what I'm talking about.

I did this in 2001 and put a 1999 36k mile 2.5 + manual transmission from a totalled out Ranger into my 1993. The only other issue there was the 1999 had no physical speedometer sensor gear. So I swapped the tail housing from the 1993 over to the 1999 transmission, along with the plastic gear from the rear shaft.

Yes a really old thread... But wanted to let others know it absolutely can be done, just use all electronics, intake/exhaust from the 93/94. Mine ran extremely well for a LONG time, I eventually sold it.