Contour Enthusiasts Group Archives Forums General Troubleshooting surge on accelaration

I have '98.0 se w/ duratec and ATX. Sometime, not always, when accelerating at high rpm (when the secondaries are open) the engine will surge. The torque moves up and down about 20%. No CEL.

MAF sensor replaced at about 55K.
All cats replaced at 83K. (Courtesy of Ford.)
Plugs (autolite dbl plats) and wires 86K.

The MAF sensor was replaced before I bought the car (it had 61K when I bought a year and half ago.)

It has done it off and on since I bought it. It doesn't seem to be getting any worse or more frequent, just shows up from time to time. It sort of reminds of the years I drove Italian cars, and they would do things from time to time just to let you know they had personality.

Any ideas?

possibly the IMRC malfunctioning. it's opening and closing when it should remain open.

Yeah, sounds like a failing IMRC not holding the secondaries open. Might want to replace the fuel filter if it's got more than 30K or so.