My '87 hatch has a stumble in the engine that doesn't show up intil it's in third gear. I'm inclined to believe it's a fuel problem because it gets worse with more load on the engine. But so far I haven't found anything. I've replaced both filters and rebuilt the carb and it made no difference. I've checked for vacuum leaks and haven't turned up anything. I tried starting the engine with the fuel lines unhooked. It seems to put out enough fuel, but there doesn't seem to be much pressure. I take it these cars have an electric fuel pump? Maybe this is my problem? If it's not this, I'm going to dive into the ignition next. Have any of you fine Subey gearheads ran into a problem like this? Is there anything else I should be checking? Thanks for your help.

Definitely check ignition system. Start with checking condition of spark plugs and work back from there.