hi there i am new to this forum and only had my scooby a about a month but i have a problem its a wrx 1993 import and the problem is when i am driving along if i put my foot down it starts to stutter,judder and hesitate when it gets to about 4-5 k on the rev counter it only does this if i accelarate hard not when i do it gradually can anyone tell me why please ????????? also the dump valve starts to chatter and release boost pressure the clutch also slips but i am getting that replaced next week is this related i thought it may be the fuel cut or plugs or coil packs or maf sensor maybe need advice quick please help

 

From what you say , I would go with Coil Packs, Or at least fit new Plugs & make sure they are gapped to .7 if higher than standard boost is being used .6, Reducing the plug gap before fitting new coil packs will also help to idenify if the Cpacks are at fault , If the stutter lessons then its them, As they get older the spark weakens & gets blown out by the boost.
As for the Dump valve if this is not holding boost & leaking , it will also give hesitation & stuttering issues.
If you have the standard Dump valve put it back on & try , see what happens.
1 Replace Dump Valve & Try
2 Plugs & Gaps See if it gets better
3 Coil Packs
Dean