I have 97 Ford ranger 2 wheel drive. I recently changed out the motor cause the previous motor had 270,000 miles and no power going up hill. It's a 2.3. I replaced it with a used motor with 130,000 miles. I found a couple of spark plugs were broken off in the head of that motor. It looked like whoever owned previously didn't know how to take them out. It needs to go to a machine shop so I opted to use my old head for lack of funds. I still have the same problem. Going uphill is slow. Any ideas?

 

Have you done a Compression test, if not you need to.
Run the compression test, record your findings, then retest using a little oil in the cylinders, record your findings. If it is rings, the compression should go up once oil is added, if it is valves then the compression usually won't go up. This all depends on just how much wear there is in the engine.

How does it run other than lack of power ?

I haven't seen the engine so I can't really say, just thinking out loud.

Good Luck,

p.s. I just reread your posting and notice you used your old head.
If the newer engine is know good, then all points to the head.
Do the compression test, see where you stand, might need a valve job.

 

Welcome to the forum

Lack of power is usually a sign of lower compression, which you may have transferred over to the other engine because of leaking exhaust valves in the head, or worn cam/rockers

You will need to do a compression test FIRST, above 150psi is expected
You need to take compression Off the Table or find out that it is the problem, or you will just be wasting money and time on non-fixes


You can also test fuel pressure, 30psi is expected at the engine end when running
But lack of fuel pressure will show up as more of a stumbling going up a hill, i.e. like running out of gas, not a general "lack of power"


Engines made after 1980 or so usually have rings and bearings that will last 400K + miles, just better materials were available
The valves in the head are what wear out because of the 1,000+ degree temps they deal with, they are not lubed like rings are, or directly cooled by coolant like the rest of the head

The 2.3l Lima engine also uses a Timing belt, this has to be setup "just right" or compression will be low because valves are not timed to pistons

When any head is off the engine you should flip it upside down, with spark plug in place, so its level, and then fill each cylinder cavity with water, or gasoline, then wait
See if valves are leaking fluid out, ports should remain dry
Its not a definitive test but if any one of the valves are leaking the head needs a valve job for sure, all the valves and seats need to be done