Help needed with my 90 olds
 

I have a 1990 old calais with a 2.5 4 banger in it, it's my winter bomb for the last 2 winters. I went friday and had the emissions test done to re new the plates. The guy doing the test said the car passed better then most newer cars. Anyways I left there and drove 3-4 miles and then it started missing and acting strange. I thought maybe there was some water in the fuel freezing it up so I poured in a container of gas line antifreeze and added 10 bucks worth of high grade gas. I babied it home. when it's in parked you can mash the gas to the floor with no problems but when you put it in gear and put a load on it it starts missing and back firing thru the top of the engine. I thought maybe a plug or wire went for a crap so I put new plugs and wires on the car and the same thing. What could be wrong??

Ok a couple of things , did u take each wire off to see what cylinder might be missing? seeings how u did plugs and wires they should be ok , are u getting lots of gas ,borrow a gauge and check it out should be around 40 psi with the key on and the engine not running.Also when was the last time your fuel filter was changed? Check coil packs make sure they are ok,WORSE CASE IS THAT THE MODULE THAT COILpacks bolt to is going south . `Do the simple first I hope i didn't confuse u to much . The kid had the same problem with his 90 Lumina car and it turned out to be a bad coil . Later bake