My '89 F150 XLT Lariat 5.0L auto 4x2 will start just fine but after driving for a short distance of driving @ normal operating temp will start to miss and sputter. If I pull over and feather the gas pedal it will continue to do the same as-well-as sometimes back-fire. Sometimes it will catch, most-times it won't and then cut off.After letting it set for a little while it starts right up, and allow me to drive a little further and it repeats the same thing over again. If I let it set for hours (cooling considerably) it will drive further.
In the past year-and-half I have replaced the entire ignition sys. and the main and front fuel tank fuel pumps and filter for other problems.
Could the timing being slightly off, a defective fuel relay or fuel regulator cause this problem?
Thank you, Steven P.S. Someone please help!!