Driving iswara 1.3 1993 model.Every morning start the car will heat up for about 15minutes.When move the car will be jecking and lack of power.Try to rev abit then ok for a few minutes then start back.After running a long time then OK.When stop for 1/2 hour then try again still come back to the same situation.Change fuel filter,plug,did engine tuning clutch etc.Still have the same problem.Took back to mech and and did tuning again but still have the problem.Need some help from All sifu'sss urgent