rough idle

[jwetering]

Ok...what with the car running so nice and strong after my exhaust backdate, I think I'll try to address one of the last niggling little items with my 78 coupe.

Ever since I got the car, the idle, when cold, is rough at best. It seems to surge and stumble, but it never gets so bad that I lack for power or even smoothness when I let out the clutch.

The idle smooths out considerably when the car warms up, although she still gives a light pop every five seconds or so.

I had a problem with a hanging idle in the past. The solution was to disconnect and plug the vaccum line running to the idle speed smoother outer valve (sorry I don't know the technical name) This is a 2 inch high, 1.5 inch diameter device that sits just behind and to the left of the airbox. This helped a great deal, until my recent exhaust backdate, when my car was started stalling if I let off the throttle quickly and put the clutch in. I've just re-connected the idle speed valve thing, and it won't stall now.

I've not addressed my problem directly, because overall the car runs very strong, recent maintenance is as follows:

A short while back, my shop installed a new fuel distributor after I failed my emmissions test one too many times. I've also had new injectors in the recent past. Naturally the spark plugs, dizzy cap, rotor, fuel filter, and air filter have been replaced as necessary.

Does this sound like a warm up regulator? I don't have a fuel pressure guage, so testing it is a little tricky for me.

Is this maybe normal for a 1978?

Thanks for any help....