2006 Tiburon Engine

Hey guys i fixed a 2.0 liter engine for a friend that bend a connecting rod and changed bearing, the problem is that the car idled great on the first start went for a drive up and down hills and no problem. The thing was when we drove on straight flat road the car went off and did not start. When it starts, you can not accelerate because it turns off or starts to bog. What can this be? I need your help!!

My first guess is a fuel supply problem. Possibly the fuel pressure regulator is damaged, crushed fuel line, blocked fuel filter, or a bad fuel pump.

Try attaching a fuel pressure gauge to the fuel rail (there should be a fitting for this) and looking at the reading, both at idle and when the engine is under load.