y does it hesitate when warmed up
 

im havin a problem with my 94 wrx saloon,
when it warms up it has a really bad missfire and loss of power!
tried connecting test plugs for error codes but got nothing!
if left for a day goes great for 20 mins then goes cr*p after that!
ive replaced the plugs, cleaned boost solonoid and tried a 2nd hand maf :brickwall


has a z4 ecu, blitz bov and stainless cat back exhaust

any help please
thanx

anybody??

coil packs most likely, they break down inside and are worse when hot

Simon

had same problem replaced coil packs happy days
better off doing all 4 at the same time sometimes you ca'nt see a crack after i took mine off one looked perfect put a screwdriver in the end and a little bit of pressure on the side and there was just a hair line crack in it

thanx for the help guys

im having this issue on my newage wrk, cyl 4 misfire, sorted a new coil pack, will see what happens lol