96 toyota corolla 1st cylinder missfire

I have a 96 toyota corolla 4 cylinder with a check engine light on, the engine sometimes but not always idles a little rough at a stop light and rarely upon acceleration. I had a diagnostic run at auto zone and they told me that the 1st and second cylinders were missfiring. I changed the spark plugs and wires, with no improvement. The interesting thing is that it only happens sometimes but when it does it it really rough. Can someone offer any help or suggestions? Thanks josh

try getting some fuel induction service

injectors are common problems on theese

What exactly is that? Do i just take it to a machanic for that or is that something i could possibly do myself? And what exactly do they do..? replace the injectors?

Look at the distributor cap and rotor. How many miles on the car?

There are 115,000 miles on the car but only about 10,000 on a dealer rebuilt engine. But ill check the cap and rotor, am i just looking for anything abnormal? wear and tear?

You will want to look for burn marks and or cracking in the cap.

The cap seemed to be just fine, but the rotor was in bad shape, i replaced that and have not had any problems as of yet. Im hoping that was the problem, the engine light went off but my wife told me that it had been going off and on. I think that might have fixed it though. Thanks for all of the help everyone.

Well i have changed the plugs, wires, rotor and cap and no dice... the autozone diagnostic read 2nd cylinder missfire, he cleared the computer and the light was off for a few days, but it just went back on again? any other thoughts on what it might be? Its a rebuilt engine with only 10,000 miles on it. When my wife got the engine rebuilt by a dealer before we were married he told her that the light would go off when she returned to her normal altitute..(yeah right). What else could it be. the car still sputters every now and then, you can tell there is a misfire...

map sensors are a very common problem on these 93-97.
But they wouldnt really cause misfires like that, normally hard sarting issues. If the dealer rebuilt the engine maybe the oil control rings are sticking. Have you tried compressions test yet?
Injectors clogging is a very common problem on theese. ALso if you have 115k on the original fuel filter, get it replaced.. I was getting 23mpg, replaced cap, rotor, wires, plugs and used Fuel treatment and got 24mpg. Replaced fuel filter and the next tank I got 30mpg.!!!