ok so i put in a stock evo 7 engine in my evo, after the failure of a built one. it started fine and was idling fine aswell, so next day i started it again and its fine, so i let it cool down and start it again but this time its hesitating but still starts and is sputtering and dies.

what can cause this issue? my mechanic checked all the sensor and wires but still it will do the same so he said to change the map as i had a 2.1L map installed of the previous built engine. can the 2.1L map cause the car to act erratic in the stock engine? i mean below 100 load, nearly all the maps are same so i personally dont think thats the issue. i havent driven the car at all just idle and rev to 4000 rpms.

so what can cause a car to hardly idle and missfire and die?

i will upload a video by tomorrow, but for now can i have your opnions please.

 

Maybe bad plugs or ignition coil?when you acelerate, what shows your AFR?

 

i cleaned the plugs same thing. and i havent driven it yet, when it was fine just before this happened the AFR's were normal at idle 14.5

i will have to look at the ignition coils, i have the spoolin up COP installed, will put back the stock ones and see if it makes any diffrence.