The V8 engine in the Grand Marquis has developed an odd quick which can't be diagnosed though the computer codes or fuel system pressure testing, and I need help badly.
Every once and again, while driving or at stop lights, any time at all really the engine will stutter for a moment and then right itself. Were it a non-computerized/non-injected car I'd say that the coil was going bad or the condenser/points/rotor need replacing or a bad primary coil wire, or the fuel pump was failing, the usual simple fix.
None of the codes come up though, no indication that something's wrong, but there is for sure. Except for when it happens on the highway, it's a simple annoyance, but at speed, it's a bit dangerous.
I could use some serous help/opinions/suggestions. I looked and checked and changed everything and no help, even tried Dry Gas (GASP ! ! ! ) Nothing stops the problem.
Thanks—
btp76
Reader
3/16/14 10:09 a.m.
My 99 Town Car did the same thing. Only once did it give me a code for a single cylinder misfire. I swapped the coil packs between two cylinders to see if I'd get another code, but I sold the car before it did it again.
Sounds like an coil pack.
Ford used to have a lot of trouble with throttle position sensors getting glitchy. It was most noticeable when you would just tip into the throttle from a light, or at your most common cruising speed.
A duff coil, you should be able to reproduce the issue by accelerating as hard as you can without having the automatic trans kick down. High load, low rpm equals high cylinder pressures and increased output required from the coil(s).
Those symptoms are exactly what I'm getting with the Duratec engine in my 2005 MPV, so this thread just became highly relevant to my interests. TPSs aren't that expensive, I find; Rockauto offers me Standard, Airtex, and Beck/Arnley, and of course there's OE Mazda (which I assume is Ford?) Recommendations for what to use/avoid?
Coil. My van used to eat about one a year.
