It was in storage for 2yrs. Drained all fuel. Replaced plugs & wires. Cleaned cap & rotor. New motor oil,air filter,oil filter. Hard to start (cold or hot). Have to pump gas pedal to start. Runs smooth above 1000rpms. Drove 50miles to barstow,50miles back. Have to accel with one foot & brake with other to keep from dying out. Weather was 80degrees. Ran good to an from. Did not act up until end of trip. Check engine light is now on.Checked for loose wires,cracked hoses, leaks. Have a good spark at coil. Plug wires have good spark.
Engine shakes when idling below 1000rpms. on 1993 Mercury Villager
I had the exact same problem. It is definitely from a vacuum leak. Check the pieces where the hoses connect for a leak. Mine ran smooth immediately after fixing the leak. However, a vacuum leak usually doesn't turn on the check engine light. So most likely from some type on leak in the air intake. Unmetered air getting into the system almost always sets off a trouble code in the comp.