I have a 1993 ford f150 xlt 2wd 5.0 it smokes when on freeway for a wile like a haze and if you punch it you smell oil bad and power lack. Never smokes in city never looses oil in city but only if I drive for like 30 minutes or more. Has plenty of power when it is cold once it's warm a smart car could out run it in reverse and I only get 10mpg city and 12 on freeway.now stuff I did to it I have checked the timing it is within 5 degrees play Wich is good and I replaced plugs, wires, cap and button.I replaced fuel filter, tps sensor iat sensor. I cleaned Intake and throttlebody I punched the converters unplugged the egr system and the smog system no difference the one thing I did to make a difference on power was I adjusted the timing of distributer just a tad so it has plenty of power well mostly but still smokes on freeway and after adjusting distributer a tad it has power but when you crank it up in the mornings or about ever time you here valve ping so I know that's not right but if I adjust eny more one way it pings under acceleration and the other way it just gets retarded and no power and no respons like before no power when warm the only code I got before everything g was unplugged was an injector out of ballance code wich may explain why it runs weird like first start smooth after run for 5 Second it misses Lil bit and randomly misses on what feels to be 1 cylinder and as it warms up the miss gets a Lil worse to were you can feel it under slight ecceloration but if you punch it. It will lite the tires and would take lag a bit and sometimes I stop and engine runs smooth other times it's like that 1 cylinder keeps missing and I think k maybe I have an injector going bad but seams like everything else maybe tied in with it. Like it loves to over heat well try I shut it down at three quarter mark or l of nomal but it runs city below normal and if you strap a load to it city will o er heat freeway keeps it cool but ow if your empty and on freeway I half to leave heat on to keep it from getting to l of normal and if I'm hard on it it tyres to over heat I have replaced water pump and thermostat flushed the radiator and heater core and new hoses everything g with a 180 cool Stat thermostat in it and it still does it soon idk my dad told me oh the rings are getting bad and the Pistons are about to explode and I had a professional ase master look at it and ran some test and vacume test and told me there's nothing ron with it. It's a perfectly good running 302 and so I told it to a friend who builds 302 engine and he looked at it and said punch the Converter so I did and he said check timing so we did and he said check your distributer for play and we did and nothing he went over it top to bottom and sense it checked out OK on vacume test the rings are fine well compression. Enyway so someone help I drive it everyday I love it but if she ain't gonna run. Right image tear the engine apart and ground up if I half to I take pride in my truck I will do whatever I half to

 

Welcome to FTE.

So, what are you asking? You say you checked compression and it's ok. But it loses power and smokes when it warms up. It overheats. It is an EFI motor, but some of the emissions stuff like EGR and "smog system" have been disconnected. It gets poor mileage.

Usually, the suggestion is to return the engine to the stock specs, emissions and all, and diagnose it with the OBD I codes, do the compression test, etc.

Let's just go after the smoke first. Have you checked for leaks? If the rings are good, the other suspect internally is the valve seals. Stock Ford neoprene umbrella seals start to harden, crack, split and fall apart as soon as the engine is first started. The chunks block the oil returns, so sometimes oil builds up in the valve covers and can be ingested via the crankcase breather/PCV system. You still have the PCV etc?

So, check for leaks, then pull the valve covers and check the seals.

Also, when posting, please:

--Spell correctly.
--Make sentences with periods and capital letters and all that.
--Make paragraphs for each subject you are talking about.