Chevy spark engine immobiliser bypass. Has a keychip. Engine turns but no start. Replaced Fanbelt. No loose connections.

Either the engine isn't receiving fuel or if a petrol engine there is no spark...

Perhaps a wire was missed when connecting the battery or perhaps there is an immobiliser.

Whatever the fault, only systematic checking is a sure way of finding it.

jump starting an engine will sometimes corrupt the program in the CPU . I would have the CPU reset using a code reader first so that the immobiliser was reset before I did anything else.

I would be checking for a loose battery terminal ( from the bump) or a damaged battery. The immobiliser normally will not allow spark and normally does not stop the cranking action of the engine. If it is an auto a broken isolator switch for the park/ neutral position will also causes the fault

check the battery in the key and the engine immobiliser for operation

It has nothing to do with ECU and immobiliser even if you turn your ECU OFF your car will start and will your but not properly without CPU your car will work in emergency mode. try finding Idle sensors and check them if they are ok

not unless you are a skilled electrical engineer. the immobiliser is within the computer.

think you need to have the factory immobiliser reset ,dealer only

just put a compression gauge on each cylinder that will let you know if engine has a bent valve, gauges are relatively cheap. if the belt didn't have anything to do with your timing belt i doubt you have a bent valve, any check engine light? do you have spark? fuel pump turning on when key is turned to on position?

i had this problem and again it was narrowed down to the immobiliser. however it wasnt exactly the immobiliser it was the immobiliser coil. it sits around the key slot and it is the radio part that check the chip inside the key. got mine replaced and it starts first time every time now. it cost £35 to replace.