new owner-86 Ranger 2.3 Diesel

Last month, I bought an 86 Ranger Diesel and have been trying to find all the info about this motor as I could. That's what led me to join this site...I didn't know the D50 came with the same motors as an option. I'm in the middle of replacing both timing belts are a precaution...as well as other little things that I've found. One of which is the coolant temp sensor for the dash gauge. The old one resembles a Ford knock sensor and I don't see the portion that sticks out into the coolant stream. Can I replace this with a more modern sensor? I've grounded the plug that goes to the sensor and the dash gauge slowly swings to full hot and a buzzer starts sounding about half way, so all that is working properly. Also, why does the sensor appear to have 2 prongs, yet there is only one wire going to it from the wiring harness?

Next is the air filter. It still has the stock air box on it, and the only number I can see on the old filter is 546131. It has an orange outer foam material, so I was thinking it might be WIX or Fram or Purolator...yet I can't come up with anything using the 546131 part number. Any ideas?

The problem is, ford made a lot of things on the engine their own...as ford tends to do, like the vacuum pump.
I would check with carquest to see if they can cross that filter number. Also are you sure its not an 85? I am almost positive 85 was the only year the ranger had the 4d55 as an option, and older was the 2.2 perkins

coolant sensor wise, replacements all have 2 pin (for automatic transmissions that need a sensor for when to allow overdrive) so its cheaper to make one with 2 pins than 2 different sensors.

Thanks for the reply. It's indeed an '86...built in May, IIRC. Good idea on carquest...or maybe NAPA could find something. There is a thread here about a mystery sensor on the side of the head near the injector lines. The sensor I'm talking about is the same sensor...and I've determined that this sensor just threads into the head, but doesn't extend into the coolant stream. I did some testing on it and found that one prong is grounded and the other switches to trigger the warning alarm. To my surprise, it works...so I'll just re solder the connections. The strange part is that the sensor has the 2 prongs as I mentioned, but it has only one wire that extends from the plug which plugs into the wiring harness. Strange. I thought that I could T into the front sensor(near #1 injector) and run a modern coolant temp sensor that actually will give a more accurate reading of coolant temperature.

rangers were available with the 4d55 from 85 to 87. they sold over 220,000 of them from some numbers I have seen, but have no way to verify.

How far should I let the motor wind out before I shift? What RPM?

5200rpm is the redline if i remember right, dont think it makes any power above 3000rpm though

Our 4D55 motors are governed out to 4200 rpm, which is convenient because that is also when it makes highest rated power. 80hp for TC05 motors, 86hp for TD04 motors. I usually rev mine to about 2900-3200 rpm before I shift, but I'm also running 4.222 rear end gears, so yours may behave a little differently depending on your gearing.

That's when the Rangers tach starts to show redline. 4500RPM...and goes to 6K. I've been shifting it at 2500 max and was hesitant to let it go any higher. I figure peak torque is at 2K RPM, so when it falls into the next gear, it will be at or near peak torque. I'm also shifting with fuel mpg in mind.

Rear end is 3.45 fwiw.

Have any pics?

Well, that didn't work. Try these:

https://i.imgur.com/t3MwvgH
https://imgur.com/F4VBFKe
https://i.imgur.com/VMANOAG

The biggest downside to the ranger version is the ford only alternator+bracket, AC+bracket, Vacuum pump+bracket, and Serph balancer. the normal everywhere else version has the alt at bottom of passenger side of engine with vacuum pump on back of it, and a/c compressor on driver bottom.
Not sure where ford has the power steering pump, but the normal is passenger side above the alternator.

Just me commenting on the pics

The power steering pump is below the A/C compressor and the vacuum pump is below the alternator. I haven't looked at what brand the PS pump is, but it's not one of Fords run of the mill pumps. It may be a factory Mitsubishi unit, idk. This truck appears to have an original 81K miles although it has seen some wear and has also been towed behind an RV at some point in its life. It also hasn't been on the road(until now) since 2007. I plan to run it on veggie oil in the near future...should be a neat project. Timing belts were the first thing I replaced on the motor along with a few other items.

I wouldn't run pure Veggie oil, especially used, unless you make sure it is clean. The injection pumps are old and worn, and veggie oil can clog them up quickly.

Isn't there a way to DIY refine cooking oil so it's safe? I've seen it clean the innards out of diesel engines like magic.

Yup you can set up a basic filter and do some transesterfacation and run 100% chip oil no worries. Engine will run for years on homebrew stuff no issues

From what I've seen, there is a 3 step filtration process that the WVO needs to go through, then it has to sit for some time to allow any left over impurities to settle to the bottom of the container. I still have more research to do on the process of running on WVO, but this is my understanding so far.