Chevrolet Repair: 1996 CAVELIER HOT START PROBLEM, fuel pressure regulator, oxygen sensors

Question
Hi MARK: Sure hope you can help this car is driving me nuts. Cold starts are excellent and immediate. Once engine warms up, the only way to start it up right away is to keepthe pedal all the way to the floor for about 3 or 4 seconds. Once it starts it runs perfect. This to me is strange because i've always been told using the pedal starting a fuel injected car has no effect. Spark is fine, i've replaced the fuel filter and both oxygen sensors. o2 sensors are working fine i've checked them with a scanning obdii. new air filter, the obdii shows temp sensor is working or at least temp rises as car warms up. so i'm not sure its the coolant sensor. again cold starts are immediate and fast.Problem arrises only when the car is at operating temperature. please help, any suggestions will be greately appreciated. if it starts cold, fuel pressure must be ok. I can't think of what to do next. And i cant understand why it starts warm when the gas pedal is all the way to the floor. Must be air related i have no idea. 1996 chev cavelier, 2.2 liter 4 cyl fuel injected

Answer
Hi Alex, the only thing that comes to mind is the fuel pressure regulator. I'm thinking that maybe it is leaking fuel into the intake and causing a flooding type of condition. This could also happen with a leaking fuel injector but I have not seen this happen. What your doing when you hold the pedal to the floor is stopping the fuel from being injected at wide open throttle.

Hope this helps

Mark