I have 1987 Cougar 130,000 miles that runs good until about 10 to 15
minutes of driving it will start to midly miss, you can feel it
shudder when driving. It does not miss under acceralation just on
crusise. It seems worse around 45 when climbing a small hill, but you
can stomp on it and not feel it miss. At crusise around 70 to 75 there
is this small shudder. When it happens it is intantanous, but it is
just after driving 10 miles or so at highway speeds. I have given a
complete tune up a year ago, plugs wires,cap, rotor air filter,PVC
valve. No engine check light comes on. Any ideas?

"n0nsx (AT) direcway (DOT) com" <n0nsx (AT) direcway (DOT) com> wrote:

No hesitation or idle problems, otherwise?

What brand plug are you using?

I suggest you have the codes read out... sometimes a DTC code will exist
without setting the light

--
Yeh, I'm a Krusty old Geezer, putting up with my 'smartass' is the price
you pay..DEAL with it!

<n0nsx (AT) direcway (DOT) com> wrote

Are you sure it's not a torque converter shudder?

CJB

If it has a distributor try replacing the rotor and cap.
Could also be the start of a problem with the TFI (thin film ignition)
module bolted to the side of the distributor.