My 1999 Ford Contour was running rough at times. Felt like the gas peddle just went away and I had to let off to get it back or it would stall. Changed Mass Air Flow sensor with no luck. No engine light and no clue now. I have put new fuel filter and fuel pump is a year old. Please help? No codes and no luck leaves me along side the road twice now in a week.
There is a Service Bulletin on a hesitation/Rough Idle on Warm Startup. It was put out on 5/15/2000.
It states that the PCM (Powertrain Control Module) should be reprogrammed to repair the condition of Hesitation/Rough Idle on hot startup.
This reprogramming can be done at a Ford Dealer by a qualified Technician.
When you bring your vehicle in for service, just mention to check the following Service Bulletin.
Rechecking the fuel pressure and fuel volume should also be rechecked. Just because the pump is new doesn't mean it can't fail again. It happened to me, the pump was in about a year and the car started to stall and then restart before it could be checked. It had me going nuts for a while.
Let us know how you make out.
Now I have a code of P0190. I know it has something to do with the fuel rail sensor malfunction but it doesn't say if it is the pump, the pressure regulator or what it is. Can it be more vague? What is most common with this code and where do I start to look? Thanks
If the car is indicating a fuel problem I would check the fuel pressure first.
The sensor can malfunction causing a PO190 code and still have the engine run fine.
A faulty Fuel Pressure Regulator could cause a fuel pressure problem
The code PO190 is for the Fuel Rail Pressure Sensor voltage problem.
The Reference Voltage should be between 4.0V to 6.0V.
Try wiggling the connection and also tap the sensor to see if the Voltage Reference changes.
Make sure that the Fuel Pressure is at about 40PSI, and that there aren't any leaks in the system to cause a pressure drop.
This is just a start to diagnosis this problem. Get back to us with more information and we can diagnosis this further.
If you are good with cars then you can get all the information to your car at ALLDATAdiy.com.