mardimacfly

New owner of a 1978 Chevrolet g30 350 5.7l with an edelbrock carb, named Lucky Number Two.
When cold, it idles rough in park, reverse, neutral and drive. After it warms up it will idle fine in park and neutral but not in reverse or drive. Acceleration is fine. All this happened after a burst hose and possible overheat. (temp light never came on). No signs of oil/coolant mixing. No moisture in tail pipe.
Checked spark plugs they all look good. Checked under distributor cap, all dry.
Furthermore, temp light does not come on when key is in on position. I grounded the wire and the light comes on. Changed coolant temp sending unit and still the light doesn't come on. Don't want to risk future overheat so I'll be installing a universal temp gauge when my wallet allows.
The pcv valve is missing and the evaporative emission control canister is completely disconected. Also there is a electric choke on the carb which the wires are disconnected.
Doing compression test tomorrow.
Any advice?

canucklehead

In gear is slightly lower in rpm making any off idle issue worse. Try using a propane torch to allow some propane leak out by the intake manifold. If you hear the rmps smooth out or increase then you have a vacuum leak.
I would go and pick up an aftermarket guage trio and add it. I hate idiot lights. I wanna know what the engine is doing. You can wire them up to the wires coming from to the dash and you will have a more accurate reading.