overheated 4G15 colt/mirage/summit hesitating under power

[6Red]

i'm trying to get my little colt back on the road after a mild crash last winter, and i need some advice. feel free to skip the first part, as it doesn't contain any info that's not in the thread topic. thanks!

[the story]
last winter, in the second/final really bad snowstorm we had, i found myself driving on the highway. car had received some hits to the body and a flat tire from encounters with guard rails in the first/previous really bad snowstorm, in which i was also driving. at any rate, i was making my way home when a transport truck went by in the other direction, dumping a load of wet snow on my windshield, completely obscuring my view. my only option was to let off on the gas, and try and keep it on the road. but what seemed to be a straightaway turned out to have a bit of a curve in it, and when the snow cleared i was headed for a guard rail. again. i managed to turn the car enough that instead of hitting dead centre, the rail hit in front of the wheel. luckily it was of the post and cable type that rises out of the ground, so the bumper and wheel hit, the whole car sort of jumped off, and other than the blow kicking my head into the roof, i was still on the road, in my own lane, and ok. i pulled over, and everything seemed fine. however once i started driving again, the heat went out, so i stopped again and found the radiator was leaking. i was most of an hour away from the next town, and i had to keep going. i had with me a 1 litre bottle of water, which i poured in along the way. i also tried refilling the bottle with snow, but it being that it was -35C outside and there was no heat, the snow didn't melt very readily and the rad went dry. i made it to the town after the engine overheated and stalled three times, and from there i had it towed home. i actually drove it home from the garage i had it taken to, since i wasn't sure what i was going to do with it and it was only a few blocks, so it obviously wasn't as bad as it could have been.

[the car]
1994 colt, with the 4G15 model 1.5L 12-valve SOHC engine, with about 178000km on it. the only pre-existing condition was a cracked rubber pipe-thingy that connects the exhaust manifold to the rest of the exhaust system. there is also a bit of oil seeping out the front by the plugs, but that's nothing new with these engines afaik. the radiator was ruptured in the impact, and was replaced with an identical one from a '95 colt that also has a bad (worse) engine.

[the problem]
the car starts fine, in fact better than it did before the crash. and if you press on the gas extremely smoothly, it revs up just as well as it used to. but otherwise, the engine hesitates badly on acceleration. there's some smoke out the exhaust when it does this, but not enough to tell if it's white or blue. smells awful though, obviously. there doesn't seem to be any oil in the coolant or vice-versa. also i don't remember if it was like this before, but the ignition system seems louder. you can hear the current running through something when the spark plugs fire.
i've been focusing on the intake side so far - following is a list of things i've tried, and the results:

• replaced rad, flushed 3 times to remove rust/anything else - stopped overheating (obviously.)
• fuel injector cleaner - no change, but may be contributing to some of that smoke.
• compression test (dry and wet) - three cylinders are close to the nominal 190psi and one is a little lower but still within 10%
• replaced fuel filter, spark plugs, and distributor cap - no change
• cleaned airbox, filter, and butterfly valve - no change

[the plan]
nothing has helped so far, and i'm getting a little discouraged. i'm not a mechanic by any means, but i am technically inclined, so i'm trying to do as much as possible without paying for outside help. the engine light is not coming on, so i'm not sure if there's a point in getting the codes read or not? next i plan on switching out the distributor, and replacing the O2 sensor and thermostat. oh, and completely draining the oil, but i doubt that's the problem. if none of that works i may muster up the get-to-it-iveness to change the whole fuel injector assembly. but beyond that i'm at a loss. if you have any suggestions i'd love to hear them!