88 merc grand marque, 5.0 L, FI, Air, 160K.
Problem: rough idle, stalling, choppy during normal driving, hard to start.
EGR valve has been replaced, same problem. However, when the vacuum line to the EGR valve is disconnected the problem goes away. I am not really sure what the EGR valve does or how it works. Could there be some kind of blockage in the air plenum that it attaches to. Any ideas on where to go from here would be appreciated. It has new plugs, wires, rotor, coil, and fuel filter. Thanks in advance for any help.
Thursday, March 15th, 2007 AT 10:19 PM