I am trying to help my son-in-law with his 96 Mazda Protege. It falls to a very low idle at stop signs. It keeps running but at a very low idle. At times, it falls to about 200 rpm and then jumps up to about
400 - 500 rpm. The period between falling to 200 and jumping up to the larger numbers is very brief... about 3 or 4 seconds. I should mention that the car was give its 90,000 mile tuneup recently where the following items were changed: fuel filter, air filter, plugs, plug wires, distributor cap and rotor. I am not sure what is happening and would appreciate some suggestions.Thanks, Al Kondo