I have an 88 2.3 ranger. The problem is, about the distance from

Thermostat isnt going to cause misfires. Period.
Older fords like that are really picky about the coolant temp sensor though. I had a 94 2.3 ranger that ran like shit cause the ect sensor was busted. Fixed that and it went back to normal.
When chasing a misfire
Check your ignition system, including plugs wires cap rotor and the tfi module. I believe the 88 is old enough to still use one.
If its got the tfi mounted on the distributor, take it off and have it tested at vatozone or somewhere. But not just once, like a multitude of times. Theyre know for going bad but you have to get em hot to show it when tested.
Also does it ever run fine? Like when its completely cold?

I couldn't imagine a stuck open thermostat causing a misfire. It just would run cold. Check the simple stuff first. It probably won't help but cheap OBD1 scanners can be bought for those fords to pull codes. Check for fouled plugs, ohm out the wires, and check the disturber cap for corrosion. After that check timing, maybe the belt has slipped a tooth.

>>15585015
Runs like a fuckin dream when it's cold. It only starts to act weird if I drive it the distance from work to a little past my house approx 15 miles.

>>15584950
as >>15585015 said I would start with the ignition.

Heat causes bad ignition parts to show problems, given that it only shows up after a lengthy drive I would assume that's whats causing it.

>>15585032
Our mechanic Kenny has an obd1 and were gonna have him test it. I've not checked plugs yet. That would be a good place to start. I'm gonna go do that. Will keep you all updated.
>>15585048
Explain to me why heat causes ignition parts to show problems. What vehicles have you experienced this in, what was going wrong with them, diagnostic process, etc.

File: IMG_20160807_215842.jpg (2MB, 1944x2592px)

2MB, 1944x2592px

Looks bretty gud to me. Now that I see these are OK I'm leaning more towards a new sensor.

The TFI module is solid state and if it has a poor solder joint on its board it may not act up until the board heats up and that solder gets hot and makes a poor connection.

>>15585126
Tfi module? What's that?. What does it do?

>>15585150
The TFI module (also known as a spark module) is necessary to control the spark output of the ignition system via the EEC (electronic engine control) computer. A signal from the TFI module is sent to the EEC and the computer then controls the spark to the spark plugs.

>>15585243
Gotcha. We all collectively don't think it has anything to do with the tfi module. However, I called the mechanic, he says he wants to run the scanner on it. Thinks it's just a temp sensor. I think we have it settled. However if that doesn't fix the problem, I'm moving on to tfi module.

>>15585262
I would still Ohm out the wires if you have a wire with high resistance that could be causing it as well.

>>15585279
Gotcha. All noted. This problem is beyond me. I'm not a complete car noob I'm just young and don't quite have the experience for this type of problem.

Update. At the mechanic. So far I got it warm enough to the point where the problem occurs and it gets voltage in the distributor but no spark.