Help, Bad Injectors? Hesitant/Backfiring

ok, today i left school and when i started the car, the idle was fluctuating about 150 rpms for 20-30 seconds. i sat there and it leveled out so i figured it was just cold, i took off for the gas station about 1 mile away. i pulled up to the pump, shut the car off then i decided to get gas elsewhere since it was 2.60 for premium

the car had been shut off for about 30 seconds, i started it and took off. when i pulled out onto the road it was very hesitant and backfiring. not loud backfires, but just jerky. i wasnt hard on the car on the way to school, or leaving. never went over 2200 rpm. just appeared out of nowhere

the idle fluctuates slightly at idle about 100 rpm. i limped to my cousins house and checked it out. pulled the plug wires, and snapped them back on and drove around the block, it was fine through first and second gear then it came back. then i changed the fuel filter, it was fine down his road through third, then taking off from the stop sign it started again.

have checked timing, plugs are new, new cap and rotor, new fuel filter, fuel pump is fine, plug wires are fine, fuel pressure is good. we are thinking it is my injectors? its got certain rpm's at times where it runs smooth enough, but accelerating or slowing down brings it back?

anyone else had similar problems or suggestions? they are stock 19 pound injectors, with speed density still. 99k miles on car.

this weekend im installing my intake, tb, and mass air stuff so id like to order new injectors/whatever to get it going again. sorry for the long post.

did some more searching without result.

one more thing, it occurs at all rpm. highest ive gone is 3000. the times i can get it to run smoothly at a consistant speed is right around 1400 rpm.

i can hope? what else can i check for?

im just buying some new injectors if that is most likely the problem. we did a compression check the other day also, and i still have 125 compression.

the car seemed to have been fairly unmaintined before i got it. had the original fuel filter with 97k, dirty ass k&n, timing was set at 28, had badly gapped old plugs (10 to 67), and cap and rotor were old and dirty.

seems logical with that being discovered some dirt could easily have affected the injectors. just need some opinions or anything else i can check for by tomorrow before i place an order.

ill just pick up another set. this past weekend we just put the plugs in though.

my car was running bad then, so we checked my plugs and they were gapped wrong, and 2 were cracked. so new plugs and cap/rotor were installed then it ran great until today.

this weekend i was going to install intake/mass air/ and tb anyways, so ill just thow some new plugs in again with that.