Problem No power on take off

[bochiman]

lately my 2005 subaru libery 2.5L has been having problems with taking off if i plant my foot all the way the car has next to no power, as the revs climb slowly the car jolts and gets little bursts of power, it is very inconsistant the car will sometimes take off ok but other times it will do as i said, i took it to my mechanic and he replaced the spark plugs and it seemed to have fixed the problem for about a week and now its back to how it was originally. Im hoping that somone may have had the same problem and had found a way to fix it. any help would be much appreciated thanks

[marki]

Possibly replace the coils

[champ]

Fuel filter?

[jslayz]

Fuel supply issue I would expect.

Have you run some injector cleaner lately?

It is also possible it's extreme heatsoak......

J

[rooby]

I had similar symptoms in my old car and it was the coils.
And in another of my cars way back there were similar symptoms and it was the leads.

The roughness comes from not having all cylinders firing all the time.

So I would check problems related to spark (seems like your mechanic agrees with his first impression being spark plugs).

[jslayz]

its a non turbo duoh!, shouldnt be heat soak then.

If fuel filter has been replaced and injector cleaner run it will have to be leads or coils.

I have similar and very intermittent issue, ran injector cleaner and half a tank later was suddenly running much better.

J

[HyRax]

My old MY01 Liberty RX had bad leads and coil - car running rough and an apparent loss of power. Turned out I was effectively running on only two cylinders due to two spark plugs simply not firing.

I got the coil pack (two terminals were rusty and just didn't conduct anything), spark plugs (may as well at the time) and leads replaced, and the power of the car just magically sprang back. Massive difference.

[bochiman]

This helps a lot guys thanks for the input