hard shudder during acceleration, cel blinking

having a prob, during light to hard acceleration, my 97 expedition just started shuddering pretty bad, the CEL is also blinking, been told a coil my have gone bad? does this sound right? the shuddering seems to come from under the seat area, maybe trans going south? has 127k on it.
tia,
Rick, Ore

turns out one of the coils went bad, the quoted price for a tuneup, i.e, new plugs and fuel filter is approx 250$, just FYI

Glad to know you found the problem. I have a question for you though. Before you replaced the coil pack, did you have to crank it a little longer to start it. Especially when it was cold. My Expedition shudders a bit when accelerating and I have to crank it a little longer for it to start. Both of these started happening at the same time. Did you check the coils yourself, if so how did you do it. Thanks.

yes, a little harder to start, obd-2 diagnostics reader is required to read the codes stored in the onboard computer, i just had the dealer do mine, parts cost approx 105 $, plus the labor and the diagnostics, total cost is approx 250 $ changing the spark plugs is also a pita, dealer recommended, and runs about 250 $ as well
so far i've had 2 coils go out in less then 2 weeks, uncommon, but not a rarity
hth,
Rick, Ore