Unknown juddering

[Dimonsta]

Hi guys, need some help.

There is an unknown juddering of my whole RS when I put my foot flat.

What can this be?

A friend of mine said that its most likely the turbo or something similar.

[Swindog]

More info.

[markw336]

+ 1 more info is required from what yourve said it could be anything

[94 Leone]

A juddering you say? when your foot is flat? your problem is, you're accelerating too fast.

[WRXONP]

Need more info

But a stab in the dark here

Cracked coils !!!

Common as on bc5s .direct fire coils get very hot . After 20 years the plastic cracks - electricity allways takes the easiest route to earth- under light load it earths via the spark plug electrode and the engine runs smooth - when the cylinder is pressurised (on boost) its harder for the spark to earth via the electrode so in most cases if the coils cracked it will earth out the crack onto the head - it causes the car to pop and bang and surge and jerk around and generally go all crazy

Check the coils - they crack on the long piece that goes Down to the spark plug

Other things it could be is air leaks be it vac hoses leaking or the.intercooler setup or intake - bad maf and the list goes on and on

We need more info on the car - what's been done to it . When it started to do it . Etc etc can never have enough back ground info

[Jakee]

Good place to start would be over in the introductions area

[DacerX]

yea intro is usually the best, CS isnt a problem solving machine, well it kinda is but yeah

[Jakee]

 dacerx said:

yea intro is usually the best, CS isnt a problem solving machine, well it kinda is but yeah

I swear the Legacy subforum just attracts first time members lol. Legacy/Introduction/Interweb-mechanics thread lol

[Chosimba]

I've got a really similar problem with my 93 RS liberty. It works fine part throttle, then when you give it the beans it will start to studder and surge really bad around 3500rpm and continue until you let off the gas. It's completely standard. Any ideas?

[Swindog]

Leads, plugs, AFM, fuel filter could be a number of things.

[mondo]

Could be engine/gearbox mounts

[Swindog]

Actually thats a point. Busted engine mounts will make it drive like 40 t ards

[Chosimba]

Really? Engine mounts, never thought of that. Are the leads quite a common problem with the older RS subbies?

[Pappu1]

As the guy pointed above usually bad coils will have issues over a certain rpm/boost etc

They have no leads just coils in the head area on top of the sparks

And yes older coils do have issues with leaks /cracks etc

I had a similar issue on my old one as well

[Chosimba]

So if I were to replace them, which model Subaru would be best suited to take them off?