HELP PLEASE 94 GT

what modifications does it have?

well the EGR being messed up can cause some really weird problems. Look it over, check for cracks, leaks...

very dark smoke coming out of the exhaust usually means too rich a mixture, probably because the mass air flow (maf) sensor is dirty.

clean the maf sensor.

you could probably use a tune up too: new fuel filter, distributor cap and rotor, and check the spark plugs and wires.

i'm almost 50 years old myself ... and i'm no fossil

If you remove the vac line from the EGR valve, does the idle increase? It sounds like your EGR is leaking. You can remove it and clean out the passages - a piece of carbon can hold the valve open (from seating).

Good luck.

Im having similar problems, excepting for the knocking part...

I agree. It sounds like your EGR valve is going bad. The <'96 use OBD1, which is more difficult to nail down the exact failure type, but chances are your valve is either bad or needs a good cleaning. I don't know about hte FOX3 cars, but SN95 5.0's have an EGR valve position feadback monitor. If the control solenoid is being comanded to drive the valve to a certain position and the position feadback is showing something different (within a certain tolerance window), the system will set an SES light. These Ford systems have really bad idle speed control and if you have a leaking valve, the system will hunt to try and hold the engine speed. I don't know why your engine would knock, unless it's when your speed drops too low (like 400rp). If that's the case, then the controller will open up the IAC and the load will increase significnatly to try and raise the speed. At low engine speeds/ high loads, the knock threshold is faiirly low.

I blocked off my EGR valve with a custom made solid gasket. (An engine shouldn't be fead it's own S***.) My idle hunts around every once in a while I think the system is expecting a reaction from the EGR system, but I don't have the black smoke or missing you described.

Good luck, Whitecobra 95