Got a prob with my car already in 4th and 5th when i get to about 4000rpm the car stutters and wont pull smoothly.

Anybody shed any light on what its likely to be ? i replaced the wastegate actuator on a 'friends' advice didnt make any difference so that will be going back tomorow !

Thanks

 

Have you tried reseting the ECU? (Disconnect the battery for an hour)

What fuel you running?

Hope this helps

Dan

 

Is it a WRX?

They have a speed limiter at 112mph as standard, which you would hit in 5th easily, and possibly 4th.

Could it be this?

Paul

 

Could be overboost?

What modifications are on the car?

 

Sounds like the spark plugs to me. Make sure they are gapped to 0.7mm rather than 1.1mm. I had this problem, regapped the plugs and hey presto the car was smooth again

 

Does it still rev past the 4k mark or does it stop there? Limp home mode?

When was the last service?

The more info you can provide, the better bud.

 

overboost doesn't cause sturttering, it's more like going through the windscreen.

could be plugs

what boost is it running when it happens? If it doesn't do it in 2nd and 3rd is reaching less boost in these gears?

Paul

 

wow loads of replys
Car is 93 WRX, 1st 2nd and third 'seem' ok (got nothin to compare to) im running it on only optimax at the moment knocklink seems fine with it.
Someone suggested changing the coil packs, as that was a likely cause, sound possible ?

 

Ive got the same sort of problem on mine, My99 uk turbo, i've been told to get a new Mass air flow sensor! Might be worth a try?

 

my00 started slightly backing off a bit at about 4500 revs a while back, then the check engine light came on...

They replaced the oxygen sesnor under warrenty...