Its a 88 sedan with a zc fresh rebuilt block turbocharged 450cc injectors,zdyne ecu. the problem is its giving me a code 9 and it kinda jerks from 2000rpm-3000rmp only. After 3000rm if i mash on the gas it runs like a champ. Things i have changed to try to fix the problem is a new distrib. stock injectors, stock ecu and the crank angle sensor but problem is still thier. what can it be? thanks guys

 

Do you have a DOHC ZC or a SOHC?
If it's a DOHC, did you check the cylinder position sensor on the exhaust cam?

 

it is a DOHC. According to mechanic that was working on my car he switched it with his zc sensor and the problem was still their but ill try changing it just to make shure.