Lessons learned: '96 RWD Explorer 5.0/4R70W conversion into an '02 coil spring Ranger
Preparation:
1st things 1st, a couple GREAT guides and info on the swap is essential:
http://www.explorerforum.com/forums/...d.php?t=302956
http://www.therangerstation.com/tech...er_ranger.html
http://www.rangerpowersports.com/for...ing-guide.html
2nd, having the Ford EVTM for both the Ranger and Explorer of choice is essential
3rd, buy a wrecked, complete, running Explorer. I needed a ton of brackets, cables, wires etc that go along with the conversion.
Up top, nearly everything fits tight be well, bolts in, looks like it belongs. It's underneath that in some places, space goes away and things can get complicated.
Under the hood:
I thought the round '96 Expo air filter box looked out of place so I swapped in a later '98 square filter box and intake tube. Pulled the original '96 MAF out of the round box, was a perfect fit on the later pieces. Did have to plug a breather hold in the top of the tube. Might be personal taste but I do think it looks better (and uses the same '02 Ranger air filter).
Always thought the rats nest of crisscrossed ignition wires at the coil packs was unattractive. Rebuilt the bracket to turn the coil packs 90° so the electrical connections face to the rear. Since the towers are triggered in pairs, this allowed for all the front towers to run one bank, and the rear towers to run the other. To help eliminate confusion, I did number the bracket with appropriate cylinder numbers. It's personal taste but I do think it adds neatness.
Best fit for the fan shroud was to re-use the Ranger 3.0 shroud with 7/8 trimmed off the leading edge of the shroud to account for the thicker radiator core. Also needed to trim 1/2 off the bottom of the right side shroud mounting tab. As modified, the shroud fits the radiator well and has the fan centered in the opening. The fan opening in the 3.0 shroud is quite a bit higher than the 5.0 one and the way I've got the engine in the bay, fits well.
Wiring the non-PATS PCM to the Ranger harness was a snap built a 16 long adapter using a matched pair of 42 pin connectors from a breakers yard. Made the handful of changes needed within that adapter. Having a copy of both the Explorer and Ranger Ford EVTM's was essential to sort out the wiring.
The '96 Expo engine temp sensor did not match the '02 Ranger gauge. Swapped in the original 2 wire Ranger sensor, but was able to leave it with just the Expo single wire. Works perfectly.
A/C System:
Hands down, the trickiest wiring was for the a/c compressor clutch. The Expo and Ranger use opposite logic for the WOT relay and clutch control. I removed the original Ranger compressor clutch fuse, grabbed the ground path for the Ranger a/c harness from under the fuse/relay box, tee'd off the wire going to the PCM from the a/c switch in the cabin and swapped the pins on the output of the clutch relay.
Both high and low pressure switches are still in use, the PCM correctly controls the clutch for WOT, Just like they should..
The Expo primary a/c hose assembly was a perfect fit to the Ranger condenser and accumulator but, to do it again, I'd use an Expo evaporator and condenser to evap hose. The different inlet angle would add much needed clearance, particularly with the Torque Monster headers.
Power Steering:
High pressure power steering line: Used a 3/8 hydraulic union to marry most of the 5.0 hose to the rack and pinion end of the Ranger's original hose. Quick, easy and inexpensive.
Fuel System:
The fuel pressures and fuel pressure regulator systems are quite different between the early Explorer V8's and the later Rangers.
The Explorers (through '98) use a nominal 2.5 3 bar system with the FPR at the fuel rail and a return all the way back to the tank.
The later Rangers use a nominal 4 bar system with the FPR in the fuel tank and a pressure bleed off circuit leaving the fuel filter going back to the FPR.
Running the 3 bar system at 4 bars of pressure is asking more than the PCM can accommodate, perhaps replacing the 19 lbs/hr injectors with smaller ones, say 14 lbs might (at a cost) and using a later non-return fuel rail could keep things happy.
Another option would be to find a suitable FPR for the in-tank system. Dropping the pressure there would allow an early Expo V8 to run with the later non-return fuel rail correctly.
But, since I did not want to experiment with smaller injectors and did not have access to the Fuel Pressure Regulators R Us catalog, I decided retain the Explorer's fuel rail/FPR and adapt the Rangers system to accommodate.
Dropped the tank and removed the original FPR. Did swap in a new fuel pump while there.
Used a length of 3/8" generic fuel line repair to get a proper line connector and silver soldered it to the end of the front half of the Expo fuel return line. I've read of guys using compression unions and sawing off the 3/8" nipple off the back of the Ranger fuel filter.
Since the Ranger's fuel lines are different sizes at the inlet to the Explorer's fuel filter, I used push on fuel line unions to swap the 5/16" and 3/8" ends on the pair of 5/16" lines.
Once done, the Ranger's fuel supply plugs into the Explorer fuel filter inlet, the Expo fuel return line plugs into the Ranger's pressure bleed line and the Expo fuel filter pops into the Ranger's bracket like it was made for it.
Lastly, I found that both the original and a new FPR ran at the bottom of the pressure window for the system, added an adjustable FPR set to the upper end of the pressure window. Fuel trims run about -7% or so at high way cruising, nothing the PCM can't deal with and should improve fuel atomization.
Transmission:
While the 4R70W transmission is out, take the time to change the filter and inspect the 1st/2nd accumulator springs. They're notorious for breaking causing harsh up-shifts into 2nd. I've no idea what the broken spring color is, and did not find any info on the yellow upper spring. I swapped in a matched pair of white/pink springs.
Added a drain plug in the trans pan while there:
To be continued ......