Hay i have a 1991 subaru gt legacy.the car starts fine but runs a lil ruff,but its wen u give it a little throttle it runs more rrough and then u gve it more and then its alryt.the coil packs r fine and i changed da fuel filter but dnt no wat else to check.thanks

Could be a few things, if you pull the plug wires off the coil and there a little bit corroded and light green in color I would replace your coil. The easiest check is to check and see if the EGR valve and vacuum solenoid are working properly. Locate the EGR valve, It's about 6 to 8 inches from the throttle body towards the drivers side. It looks like a small stepped flying saucer about 3 inches in diameter with a vacuum line going to it. Get something like a golf "T" to fit into and plug the vacuum line once you have disconnected it. Drive the car to see if there is any improvement in driveability. If not, then there are more things to look at but those are the most common. I hope this info helps.