Ok i have a 86 mustang GT and when i start it the idle fluctuates up and down up and down ect ect. then after it gets warm it somewhat stops. Can this be from the egr valve or what?

 

<FONT face="Arial, Helvetica, sans-serif" size=3>I am willing to bet its your idle air control valve. You can try cleaning it out with some brake cleaner and it might solve your problem, but if it is really gunked up more than likely the brake cleaner wont work and you will need to go to ford and get a new one.</FONT>

 

EGR probably