1998 Town & Country--Rough Idle/stalls

[lhargrave]

Started rough idle 500 rpm-800rpm up and down, and stalling at idle & low speeds about month ago. Cleaned throttle body, replaced plugs (they looked rough) and wires. Idle still rough, still sometimes stalls, and noticeable miss at cruising speed, no miss during acceleration. Maybe bad coilpak..???

[Alphabravo]

Could be a vacuum leak, or the idle air control. I would not replace the coil pack just yet. is the miss on the same cylinder? If a coil was bad, you would have two cylinders missing, because there are three coils in the coil pack and one coil runs two cylinders.

[Alphabravo]

OK the miss at cruising speed could be a separate problem. I heard that you're only supposed to use Champions, Bosch are no good in these motors.

I had an occasional miss at cruising speed in my 92. It turned out to be the wires.

Also, I did once get a bad plug and another time a bad set of wires from Auto Zone. Just because you recently changed them doesn't mean the new ones are necessarily good.

I would still check the IAC or look for a vacuum leak for the rough idle.

[lhargrave]

Forgot to say it's a 3.8 engine. Scanner showed Cyl 1 misfiring this morning so I thought I had a bad plug and bought another one and switched it out. No change, and then scan showed 1 & 4 misfiring (same coil in coilpack) so replaced coilpack and again no change. Now I'm thinking crank or cam sensor and from what I've read on the web either can fail intermittently and never throw a code. What's so puzzling is I have no miss during acceleration, only at a steady cruising speed or an idle. Suggestions..?