My 1993 Suzuki Samurai will not idle when hot.Idles perfectly when cold.It also backfires when running against compression.

With throttle held wide open... A good running engine should produce 140-160lb compression

From a cold start my sami idles really fast, but as I drive it and the engine warms up it will idle correctly. Is there a way to make it idle slower from a cold start?
what engine ? 1.3 L
carb or EFI? (94 was first year of efi, and many have been converted this old)
but the answer is the same , that is normal.
on car its a fast ilde cam on the carb.
in EFI its on the software and in the IAC thermal valve.

dont know if this is the same but i had a sj with same problem when it wwas cold it run fine but when it was at temp it cut out and revvin up and down ended up havin a new carb which was costly and hard to find now ...

check the carb main jets i just had that problem rebuilt the carb and fixed it. auto zone has rebuild kit for around 30 dollars easy to rebuild if you take a lot of pictures!! spray all the jets out with carb cleaner around 4 dollars

Run a fault code test as a starting point for diagnosis of this problem, learn how to do that here

Check the operation of the coolant temp sensor.
Check the thermostat is also working properly.

First ck for a vacuum leak listen for a small slight hisssing noise. and ck pcv hose and valve. the normal rpm is 750 to 850 from the front of the vehicle look on the right side of the carburator youll see a screw at the base of carburator turn it in and you lean the vehicle out which you dont want. turn it 1/4 out and see if it idles smooth, if neither reacts than you got a vacuum leak going on

Yeah it sounds kinda high. There is no adj except for the idle screw on the throttle, the computer does the rest, if it has one. If not, then you can adjust it some how. If carbureted, check for 2 little screws in the front, and check the choke, If throttle body, then just the idle screw, the idle should be around 1000. Hope this helps.

Fuel Pressure Regulator... they get old and sometimes the diaphragm wears out and you get fuel dripping into the vacuum line. This throws off the Oxygen Sensor. $133.00 from Checker; $233.00 from Car Quest. Changed mine out and voila! Perfect Idle....

88 model its a carbureter,need a clean by the sound of it