LOL, you preaching to the quire here. ..... I'm in a similar situation as you, although I think our issues are different.

My 1993 Caravan runs perfect and will cruise down the highway 75-90 mph with no issues ... speed limit is 75mph here so everybody drives 80+.
But only for about 25 miles, then the engine acts up ... I feel like it is timing, but it could be fuel. Just hard to tell if it is running out of gas or it is getting the wrong timing signal.
I slow down to 45-50 mph and take the back roads home ... it runs perfect again ... can drive 50mph all day long. try to drive highway speeds and it acts up.
Let the car cool off and sit, can drive highway speeds fine for about 25 miles.

So far I have changed every sensor in it. I started with crank sensor, even though the installed sensor was brand new. The engine has brand new coil, plugs, wires, cam & crank sensors, TPS, 02, IAC, MAP, EGR & EGR solenoid.
Every electrical sensor in the vehicle is brand new. .... And the symptoms have not changed at all. .... Same time it is a used junk yard engine with 135K on it. While changing the engine I installed all the new parts on it.
And since then I have extra sets of sensors that came with the tested to run good used engine ... so I had extras to swap back and forth ... always kept new installed after proving it was not the problem.

It had a fuel pump with about 5K miles on it. I installed a new fuel pressure regulator, new fuel filter then finally installed another new fuel pump .... and I also purchased a new fuel pressure tester ... it is right psi.

Yesterday I ordered a used pcm just to try and see if it fixes the issue .... if it does, I will spend the $250 for a fresh rebuilt pcm.
These issues can be very frustrating .... the crank sensor and fuel pumps are kinda the usual suspects. ... If I was you, I would get a fuel pressure tester ....$25 on Amazon.
If we are going to run older vehicles, they are cheaper to maintain with parts and insurance .... we do need basic tools to be able to diagnose problems .... cheaper then a car payment and full coverage insurance,

This old Hoopty Dodge Caravan was the wife mothers car ... so it has some sentimental value to it. Paint, body, interior are really nice. Has all new tires, struts, shocks, brakes .... it will be a real nice dependable car again, once this issue is fixed. Just frustrating finding it. We have owned the car for 9 years and have driven it all over TX, NM, AZ, UT, ID, WA, OR .... we love it.

 

highway driving yeah forget it with this thing even back roads from a stop you have to ease into it a bit get rolling then she starts sputtering popping back and carrying on and does not matter the speed but as soon as you stuff your foot in in it coughs a bit then takes off and you have to back off. on hills unless you get speed ahead of time (as difficult as it is)you have to drop it right down it 1st and keep RPM above 3K and it wants to go like heck. let it get to 2nd and rpm drop your done its with start coughing bucking and carrying on till yo stuff your foot back in it. Just doesn't make sense to me but i only know my way around them but stuff like this is way beyond me and i for sure can't afford $80 to $100 per hour for diag. i just don't have it. and if it's something major i can't afford that either and i can't afford to replace it. up kinda up the creek without a paddle and sinking as well as where i live currently is a non town maintained road so 4wd is a must as is ground clearance in the spring
Just looked up the timing chain kit for this truck (in case that is the issue) surprisingly not that expensive still out of the budget this month surprised though there is no listing for and guides or tensioners?

 

Do you have a Harbor Freight near you? - if so, here's the fuel pressure test gauge - https://www.harborfreight.com/fuel-i...ter-58760.html

 

Where does it idle at(rpm)? Any change after it started running bad?

 

They also loan fuel pressure gauges at auto parts stores .... I checked on them, they actually wanted a $140 cash deposit refundable when you return the tool.

I figured they were cheap enough and would use it more then once so I bought it .... but you can rent the tool for free and just let them hold your $$

 

I guess I missed your post about putting your foot into it and it taking off .... Does not sound like a fuel pump.

I use to check timing chain slop by removing the distributor cap and rotating the engine back and forth by hand. I would see how far the lower crank pulley turned before the rotor button moved ....that would be the slop in your chain.

I have a 1970 318 in the corner of the shop I can do this with ... not sure if it still works with a 1995 .... they changed many things.

 

The basics of the small block Mopar really hasn't changed greatly. That is certainly one way to check for timing chain slop. If you do replace the timing chain, be sure to install a decent double roller chain and gearset.

 

i would try that with this but the cap is such a pain in the rear to get at let alone see its tucked in the back of the engine behind intake and not the easiest place to see let alone reach i did cap and rotor this summer mostly by feel that and being winter in NH and the fact that it is getting harder and harder for me to do the things that a year ago i could handle.

 

at idle it seems fine. i go out turn the key and it will fire right up and seems to idle fine it just seems to be when driving and when it started thanksgiving day it gave no warning at all. was going great granted it was snowing fairly heavy and i was in 4wd but it does not seem to matter 2wd or 4wd acts the same. what is confusing me is if i keep the rpm high it seems to want to go but say mid throttle like out of a stop sign or light it just stumbles, coughs , and pops back almost like it's running out of gas but it doesn't seem to matter if i got a full tank or 1/4 tank it acts the same

 

i will have to see if i can record a video on a back road of how its acting and figure a way to share it here somehow then maybe folks can have a better understanding of what i'm saying as i may not be putting it out there the best but doing it how i can. my biggest issue is by the time i pay bills and buy enough propane to heat my camper for the month i only have a couple hundred $ to try to keep this old pos going