Finally found out what was causing my PO300
Finally found out what was causing my PO300 I've trying to work out this problem of random misfires(PO300) for weeks now. I've been getting misfires above 4700rpm at wot in 3rd and 4th gear and it was breaking up terribly. Here is a list of everything in order that I've done.
changed plugs and wires(ngk tr55s,Taylor T-bolt wires)-didn't help
swapped coil packs from right to left and left to right-didn't help
changed pushrods(maybe bent pushrod) that a buddy gave me-didn't help
swapped out entire fuel rail with injectors(same buddies car)-didn't help
put on the coil packs from my buddies car-didn't help
put my buddies PCM in my car which of coarse-didn't help
So I decided to go ahead and order a new crank sensor which didn't come in before Thanksgiving. So on Thanksgiving day my good buddy and I decided to take off my ASP Underdrive crank pulley and install the stock pulley and wouldn't you know it all of my problems went away. Car is running strong again with no misfires and no check engine lights.
Sorry about the long post but maybe this will help someone else in the future.
Big thanks to TILEMAN(my buddy) for letting me tear his car apart to help me fix mine.
changed plugs and wires(ngk tr55s,Taylor T-bolt wires)-didn't help
swapped coil packs from right to left and left to right-didn't help
changed pushrods(maybe bent pushrod) that a buddy gave me-didn't help
swapped out entire fuel rail with injectors(same buddies car)-didn't help
put on the coil packs from my buddies car-didn't help
put my buddies PCM in my car which of coarse-didn't help
So I decided to go ahead and order a new crank sensor which didn't come in before Thanksgiving. So on Thanksgiving day my good buddy and I decided to take off my ASP Underdrive crank pulley and install the stock pulley and wouldn't you know it all of my problems went away. Car is running strong again with no misfires and no check engine lights.
Sorry about the long post but maybe this will help someone else in the future.
Big thanks to TILEMAN(my buddy) for letting me tear his car apart to help me fix mine.
Originally Posted by DaddySS
Any idea why the ASP pulley would have caused misfires?
I called ASP and told them that I was getting misfires above 4700rpm and I told them everything that I did to fix the problem and that putting the stock pulley on last cured my problem. ASP told me that if I would have called them right away when the misfires started they would have diagnosed a bad pulley. They are going to send me a new pulley as soon as they have one available. This will be my 3rd SFI Approved pulley in 6 months because my first pulley broke(face plate fell off at wot) the pulley will cause misfires at wot under load mainly 3rd and 4th gear because it is unbalanced.
