ivan129
BlownZX
I'll try and make this a short story. I have a 1UZ (about 300kms or road use and possibly many more hours of garage idling) running an after market ECU. Engine developed a miss at idle and exhibit a miss when revved up so we found that it needed more fuel and inturn started fouling plugs. Checking the manifold vacuum we spotted a fluctuating vacuum signal. Did a compression test and found No7 with no comp. Lifted the valve cover and found that the very back exhaust valve was stuck wide open. Unfortunately could loosen the valve so the head came off. Found that the valve was seized in the guide by carbon. Now this is a brand rebuilt engine with 80lb lextreme springs. New stem seals, valve job and all lubed during assy. Has anyone got any clues as to how this might have occured or experienced something similar?