Ok - so you can't ignore the fact that the timing seems good when its cold. And you can't ingore that something to do with it getting hot cause it to act up... Thats why I was wondering if youre getting a hot enough spark or maybe a spark at all at times. If you have a volt meter you can test to see if the engine is getting a good ground. A bad engine ground can cause coil issues. In fact, you do mention you have a aftermarket coil. Can you swap it out with the old one?

That's on my 4.0 ranger that runs like a champ lol. The 2.5 that I'm having problems with has the stock dual coil packs. How do I go about testing the ground? I haven't messed with much when it comes to a multimeter...

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99 extended cab, 4.0, auto, 33s, 4x4 lifted with some stuff done

98 2wd 2.5, 5 speed, dropped with some stuff done

Read the voltage across the battery and compare it to the reading you get when you put the positive lead to the battery positive and the neg lead to a good bare metal spot ground on the engine block. The engine needs to be running so you have a load.

eidt - If you have a good ground you should have very little difference in the 2 voltages

ok Ill go check now, so one I put the meter on the posts, and the other I put positive on the post and the neg to a good grounding point on the block. this is what I did already today, and again no codes even after it was running like that.

so today I picked up a vacuum gauge and hooked it up to a line going into the intake, when running at an idle it shows the vacuum around 17, as the throttle is increased I lose vacuum all the way till its basically 0 then as the motor dies, I took 2 videos to show the gauge.

the first video is a cold start. hasnt started in about 24 hours. I then gave it throttle and the vacuum decreased, and then you can start to hear the motor choking and then as I increase throttle it sounds different. then it died.

https://www.youtube.com/watch?v=flLzJsb9hPo

second video is starting it immediately again after it died. no throttle was applied thats just the truck trying to idle, then I applied throttle about 30 seconds in and vacuum decreases again and motor runs a little better about 40 seconds in it starts to lean out and I pointed the camera at the intake so you can hear the air box making the weird noise that almost sounds like an exhaust. at that point there is almost no vacuum and then as it starts to die the vacuuum gets very bouncy.

https://www.youtube.com/watch?v=ned_MhdnNNU

so reading this link http://www.gregsengine.com/using-a-vacuum-gauge.html it looks to me like vacuum should increase so maybe i have something plugging the exhaust? that seams to make sense to me, as I apply more throttle and the truck wants to get more exhaust out the truck builds up back pressure and suffocates...

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99 extended cab, 4.0, auto, 33s, 4x4 lifted with some stuff done

98 2wd 2.5, 5 speed, dropped with some stuff done

Wow - looks like a vac leak. Is the intake torqued down good?

yeah intake is tight, i can check lines, but will an intake leak make it run that horrible?

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99 extended cab, 4.0, auto, 33s, 4x4 lifted with some stuff done

98 2wd 2.5, 5 speed, dropped with some stuff done

The exhaust theory sounds good except you should be getting an O2 code - ?

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Is it hard to upbolt the exhaust upstream of the converter, it may have gotton hot and clogged up...

You have a vacuum leak. Do you have a code reader or a scanner that reads pid's? Did the issue develop after you changed the plugs?

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It could? however you should have a p0171.

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2004 Ext Cab, 4WD, 4.0, Auto, 154k. (4.0 engine is out of a 2009 Ranger w/96k) ( as of 7/1/2017)

2004 Ranger, Ext Cab, 2WD, 3.0, 5 speed , 4WABS, crank windows, no cruise, Edge 116k.(6/5,2014) (SOLD).
1999 Ford Ranger, Reg Cab, 2.5, 5 speed, 2WD, no AC, 150k (SOLD).

i went back out and found a cracked line, fixed it and got a new video

more stable for sure, but still weird.

https://www.youtube.com/watch?v=UF57XBTTz2A

I have a scan gauge that I can set up to check parameters. what should I be looking for? still no codes or stored codes. checked again.

I was thinking about trying to unbolt the upstream o2 sensor, while it would give me a check engine light, it should at least give the exhaust a chance to breathe better. that could tell me if its the cat. I could also try unbolting it at the flange to see if its the muffler. I put the plugs in about 500-1000 miles ago, and up to the point of the timing belt it ran fine.

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99 extended cab, 4.0, auto, 33s, 4x4 lifted with some stuff done

98 2wd 2.5, 5 speed, dropped with some stuff done

My guess is something is wrong with the timing belt or you have a intake/vacuum leak. IMHO Something you did with the repairs is wrong. It is very very strange that you are not getting any codes #bizarre

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2004 Ext Cab, 4WD, 4.0, Auto, 154k. (4.0 engine is out of a 2009 Ranger w/96k) ( as of 7/1/2017)

2004 Ranger, Ext Cab, 2WD, 3.0, 5 speed , 4WABS, crank windows, no cruise, Edge 116k.(6/5,2014) (SOLD).
1999 Ford Ranger, Reg Cab, 2.5, 5 speed, 2WD, no AC, 150k (SOLD).

I would unbolt the exhaust upstream of the converter and run it. If you found a leak that means the computer may have made the mixture too rich which could mean the extra fuel was burned in the converter which may have caused it to get too hot and clog up...

I hate to sound like a DB but are you putting the ignition KOEO(SO THE CEL IS VISABLE) then checking for codes?

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2004 Ext Cab, 4WD, 4.0, Auto, 154k. (4.0 engine is out of a 2009 Ranger w/96k) ( as of 7/1/2017)

2004 Ranger, Ext Cab, 2WD, 3.0, 5 speed , 4WABS, crank windows, no cruise, Edge 116k.(6/5,2014) (SOLD).
1999 Ford Ranger, Reg Cab, 2.5, 5 speed, 2WD, no AC, 150k (SOLD).

ha yes I am checking codes with engine off but key on. I have also checked with engine running.

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99 extended cab, 4.0, auto, 33s, 4x4 lifted with some stuff done

98 2wd 2.5, 5 speed, dropped with some stuff done

Disconnect the MAF then run it.

1) does it run better or worse?

2) do this a few times then check for codes. You should have a MAF code.

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2004 Ext Cab, 4WD, 4.0, Auto, 154k. (4.0 engine is out of a 2009 Ranger w/96k) ( as of 7/1/2017)

2004 Ranger, Ext Cab, 2WD, 3.0, 5 speed , 4WABS, crank windows, no cruise, Edge 116k.(6/5,2014) (SOLD).
1999 Ford Ranger, Reg Cab, 2.5, 5 speed, 2WD, no AC, 150k (SOLD).

i forgot to check for codes after I pulled the maf. Ill go do that now, but no change in how it ran.

the weird part about it is it ran for about 100 miles to get back to my house. towards the end of the trip is when I started noticing it would not want to run at high rpms like it was starving for air or fuel, then it got progressively worse which also makes me think its mechanical like the exhaust plugging up.

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99 extended cab, 4.0, auto, 33s, 4x4 lifted with some stuff done

98 2wd 2.5, 5 speed, dropped with some stuff done