Car started having problem's about 2 months ago

Car started having problem's about 2 months ago. Stopped running. Replaced dizzy cap and coil. Go the car running again but was running around 300rpm instead of at 700rpm. When driving and putting your foot down the car would cough and sputter and rev's would drop really low like it was going to cut out. Then 3 weeks ago, pulled out of our road and the car just died, no coughing, sputtering nothing and wouldn't restart. Once the motor cooled down I got it started again and got it home again.

Right in the last couple of week's we have replaced the air filter sensor, Idle control sensor, fuel filter and today the fuel relay sensor and replaced a fuel pipe due to having a crack. The throttle body has been cleaned as have a lot of other things. Oh and we now have it back to 700rpm. Fuel is getting through but car will run for a bit then kill itself still. We do know that the ignition is worn and we can have trouble starting the car because of it but that doesn't seem to have anything to do with what the running problem.

What the heck could be causing it?