87 Ford Ranger 2.9 V6 stick

87 Ford Ranger 2.9 V6...problems started about a month ago where it would lose power. Stepping on gas pedal didn’t help...once it went through this cycle (of no power) it would even back out again and run fine...happened on inclines and straightaways. Horrible gas milage and you could smell fuel on start up.
Changed the following on the advice of everyone under the sun
MAP sensor
ECT sensor
IAC sensor
Tighten vales
Fuel Pressure Regulator
Timing
New Spark Plugs
New Wires for plugs
Checked fuel injection-fine
Also check fuel pressure that’s within the limits of almost 40 when starting and 32 pounds when the regulator takes over.
It still runs...but once it warms up...same problem but now we’ve added backfiring to the problem. Water temp (on gauge inside truck) stays within the ‘normal’ range, however the engine is VERY hot on one side...what is wrong with this truck? When I bought it the guy said he just replaced the head gasket..that was this past spring.
What’s going on...any idea’s or suggestions? :banghead:

Check compression.

Good ideal! Thanks Taillight! Think I might have found out what the problem is.... I took the little blue truck for a spin this morning around five while it was still dark out, wanted to see if the cat was clogged-even tho it was ‘checked’ by someone I still wanted to make sure, sure enough...the bad boy was glowing like a big dawg from the right before the muffler to the exhaust manifold...which would make sense because if it was running rich before I changed all the sensors and the fuel press. regulator...it would have burned up the cat converter...or I hope thats the problem anyway! Looks like another busy day with the ranger runaround

Well...it wasn’t the cat converter...what a surprise..ha. It runs fine in idle, but after running it on the road for about four miles it starts backfiring and losing power...ugh!:banghead: Is it the O2 sensor I’m wondering...no one can seem to give me an answer...ugh again! Have an appointment in the morning with a guy to have the compression checked....and hopefully tell me what’s wrong with this thing...runaround

Yes I have seen the O2 sensor change the air fuel ratio so much that the engine would die but I am also am thinking about when you said you tightened the valves. No lash could keep the valves open when the engine gets hot. Check your valve lash. You might have 2 problems. One you put in.