I have an 87 Mustang that runs great while it is cold. However, when it warms up, it begins to run rough. It is almost like it is either getting too much fuel or not enough. it almost acts like a fuel filter. When you press the accelerator, it smooths out. It seems to start when you are holding at a constant speed. And it doesn't do it too much when varrying the speed. I have replaced the fuel injectors, and many of the engine sensors. When it begins to run rough, it also idles rough while stopped. But it never dies. I took the throttle body and air intake off the other day and cleaned them well - same day I replaced the injectors. I also cleaned the EGR valve orifice as it was clogged tight. Also, when I removed the O2 sensor, it blew exhaust out instead of sucking in as I was told it was supposed to do.
Any clues to where I need to go next???

 

Have you tried plugs and wires?

 

What are your RPM's at idle?

 

When you replaced your fuel injector did you upgrade them or put the same psi, if you upgrade them you need to replace the MAF sensor to recal injectors and fuel system.


Roman 88 T-bird/gt w\347