Im having a strange problem with my Swift 1990 (Khyber shape).. the car wont start at nights & early mornings but when the sun gets out and the car gets hot (its used to park out in the street) its a half-slef start car,. even when its not used for 2-3 days, it easily starts in day time but on the other hand even if its run the whole day, it wont start at night time when the engine is cold. also its pretty hot these days here in karachi and it should not give such problems during night.
now when you push start it the car will have seriously rough idling and backfires for a couple of minutes after which the engine becomes running smooth and the car drives normally. and again, there is no such problem during the day time.
i have got its battery checked, and have opinions with 2-3 different mechanics and cng technicians. no one has been able to get a clue. please note that the head gasket was changed during ramazan and head was refaced also..
experts please give valuable suggestion how to solve this problem