In your opening statement you rated your Mechanic as the best in Karachi. Now you are saying "Ustad Hamara aisa he hai". Make up your mind bro. You seem like a genuine auto enthusiast (my assumption is based on the fact that you chose Denso to get the diagnosed problem resolved) so that means you really want to resolve the issue and are ready to walk the extra mile. First thing is to get rid of the "Ustad". Also do you mind sharing his name and the brand he works under? This way the 4x4 experienced members will be able to tell you whether you are in safe hands or not?
Also, NEVER ask for Zile Illahi's (Xulifqar) cell number again!!! This is the biggest sin one can commit on PW and you have already committed it. Just keep posting and keep praying Xulfi bhai will read your posts and respond. He is not a mere mortal whom one can speak directly to. He is our Xulfi bhai, the legends of all legends and the inspiration for Artificial Intelligence. Savvy?
