With the low, rough idle in mind, I would look into a cracked blow by hose, vacuum leak, or defective connection in one of the sensors, in particular MAF, temperature or TPS.

Plugs, wires and filters should be kept in good condition anyway, so it would not harm if you changed them if you have not done so recently.

Good luck!

George A. wrote:
> My 1.8L Subaru Impreza 1995 (manual, front wheel drive) recently
> started to behave strangely:
>
> When an engine is truly cold (mornings or driving home after
> work), it starts and begins to drive normally, however, shortly
> after that it tends to lose power for a moment or two, then
> resumes OK, then these cycles repeat until an engine fully
> warms up. Then it behaves perfectly O.K.
>
> It's kind of difficult to describe. Basically, I press
> accelerator and feel that it "does not work" - very little
> (if anything) happens; then, as I continue to hold it down,
> the car "wakes up" and finally responds and accelerates.
> This usually happens at least several times, rather
> unpredictably. It's as if the engine is not getting enough
> fuel or air, or as if the mixture is not ignited in timely
> fashion.
>
> May or may not be related, I also noticed that, when the car
> is in this state, it seems to idle strangely - an engine
> shakes (I can feel the car shaking a lot more) and tachometer
> goes up and down from high 1,000 rpm to about 100 (when warm,
> it idles at approximately 400 rpm normally).
>
> The car is up for some expensive maintenance and break job
> pretty soon, so before I do any of it, I'd like to know
> what might be the problem with the engine and how expensive
> it might be. (I can, after all, buy another car, if it
> does not make financial sense to fix this one).
>
> Any ideas? Many thanks in advance.
>
> George
>