hi there fellow friends. i have a 86 ranger xl 4x4 5 speed. i purchased this truck about 2 months ago for $500. so far i have just about over hauled the front end (new rubber, brakes, rotors etc). when i bought when i would start it up a puff of smoke would come out the tail pipe; or when i have the motor in a bind, ( taking off on a hill or down shifting to a stop). and the motor was sluggish on take off. i figured a good tune up was in order. new air filter (fram tough guard for off road truck) new plugs/wires/cap (bosch platinums, bosch 8mm wires, and gold line brass tiped cap and button. now the darn thing smokes all the time lol the engine has 144000 on it (btw its the 2.9) i know the stuff i put on it should be good, for thats what i ran on my 86 bII b4 it got creamed at 45 mph from the rear (thats a story in its self there .. wonder if there is a place to tell it on here?) but that engine had 200000 on it and would pull the front tires off the ground in first if i dumped the clutch (youthfull days) so my question is should i just drive it till it all out quits (usally when/where you dont want to brake down) or should i just budget for an engine over haul. if i do over haul im going to get the improved a/m heads for it. but should i get other machine work down or just do an o.e.m. rebuild? thanks for you time. for i know this is kinda long winded but i could go on all day about trucks

 

what color is the smoke coming out of the exhaust-blue, black, or white?

 

I would run it for a while longer to it gets worse, but in the meantime save up for the occasion. I would also recommend using a thicker oil such as 20w50, it wont smoke as bad and wont burn as much, if in fact the smoking is from blow by from the crank case.

 

As long as it doesnt burn oil like crazy, I would leave it be. Its very possible that the smoke at startup and while under a heavy load is just unburnt fuel.
Octane

 

Got a compression gauge?
Dono

 

Bad valve seals can cause a puff of bluish white smoke on a cold start up. The bad seal(s) allows a small amount of oil to leak into the cylinder while the engine is not running and this oil burns off when the engine is started, causing the puff of smoke. It is a cheap fix. There is a short cut where by you can hold the valves closed with compressed air while changing the seal, making the fix even cheaper. The seals are rubber and get hard and brittle with heat and age. Like Dono said, I would check your compression first. The most important thing to watch for in a compression test is that all of the cylinders be within a few pounds of the same reading. (10 to 15 percent from high to low) Good luck