i was having intermediate misfiring problems which was common with a ptu on its way out...or so i thought i ordered a second hand ptu from america with connectors which was apparently tested and in working order i wired up the ptu according to the tech section car ran beautiful for about a week...felt more responsive bit more bottom end and so on...it then suddenly started misfiring irradicaly when at idle it is obvious it is misfiring....however when i put my foot down it kicks out of the misfiring stage at about 5-7 rpm with a massive increase in power then goes back to running rough and sluggish for curiousity i changed back over to the s1...it again ran well for afew kms then same story can anyone point me in the direction of a solution...is it possible ive scored to faulty ptu's...even in a s2? could it be spark plugs...coil packs or fuel related? thanks for the help if anyone can assist me
If I were you I would spend an afternoon doing connector work. Clean, retension and dielectric grease every connector you can find under the bonner. PTU, CAS, TPS, CTS, AFM, injectors, coil packs, etc - you get the picture. When I did it, it felt like a new car afterwards - smooth and sweet. Even if you get no improvement after doing this, you have eliminated a whole heap of potential problems, making the real problem easier to find. I use a nail file to help the process. Ground it down in a bench grinder until it was the right width to fit inside the conectors. Lubricated it with electrical connector cleaner.
