the cure was discovered when...i converted xr2i to rs turbo bought a engine ecu map sensopr and edis4 was supplied with the ecu, fitted all together fully re-built bottom end forged up new crank etc etc...turned it on idled fine started to drive all on ofac turbo gear and it did exactly what hrst did got a guy in called auto tune somehow he thought injector 4 wasnt firing put it back on xr2i ecu it works fine....then discovered the map sensor was xr2i not turbo changed that all 4 cylinders work fine....the cure in the end was just driving the car belive it or not after all the map sensor changed etc drove a bit better jerked as soon as i try go anywhere with it, the ofab and ofac ecus require adjustment period this is where they self learn as long as all earths and loom is okay it will self learn properly beleive it or not i have dobne this twice on ofab and ofac did the same thing just taught the ecu how toi drive, it will jerk at 1 psi then 2 then 3 slowly getting better eventually depending on how it set up 10 psi like both mine did takes about 10 miles id say to run perect after this a quick test on the gas analyser prooved it running absolutely spot on