I have an 07 Sebring, the original engine started knocking, I purchased a new used engine, it came from the identical twin car color and all, tried starting, it cranks excessive, checked for spark, it has spark, has fuel, it will crank til the battery is dead if I let it, as its cranking if I spritz starting fluid in it, it starts and runs fine it drives fine, turn it off and it wont restart only cranks, sprits again and it starts and runs fine, I changed the entire wire harness, I changed the injectors, I changed the sensors, the original engine started perfectly fine just knocked real bad, I'm at a loss of what to do, I'm 1500 into it with the engine change, any advice would be appreciated, thank you

 

When you spray in the starting fluid, do you open up the air cleaner? Could there be something blocking air flow? You say you have spark and fuel. The only other thing you need is air.

Any codes? Is the intake air temperature sensor working properly?

Other than that, The only suggestion I would have is to put a case of starting fluid in the trunk and keep it handy.