I have a 71 318 4 Barrel and it has been running great but today my idol is horrible from 500 to…

Mopartooya

I have a 71 318 4 Barrel and it has been running great but today my idol is horrible from 500 to 2000 really quickly and when I'm trying to drive it misses and dies while sitting at stop lights, cruising down the highway the engine goes from two to 4000 RPM the passenger side cylinder header has oil on it is it a bad head gasket Scotty, I literally just got it registered and inspected and I'm planning to move tomorrow

Comments (5)
No. 1-5
Believe231
Believe231

Start with the spark plugs, see if they're looking fouled or are showing a lean condition. Also verify ignition timing is not sticking (if have a vacuum advance, mechanical distributor). Also hook up a vacuum gauge to see if it's showing signs of a vacuum leak-if so, try Scotty's video looking for vacuum leaks using a cigar.

Carquestions
Carquestions

This is a long shot but if the fuel tank and sending unit are original the pipe may have a crack in the neck inside the tank sucking air - pull the tank and inspect

Mopartooya
Mopartooya

I've had a similar problem with acceleration a while ago and it seem to be fixed whenever I adjusted on the idle mixture screws, today was the first day I went more than a couple of miles at one time and everything was fine till I had lunch in town and got in the truck and it started it's hiccups

Mopartooya
Mopartooya

I rebuilt the whole engine took it all apart and replaced everything new carburetor new fuel filter electric ignition, I pulled the plugs and they were clean one of my spark plug wires fell apart so I replaced it and then a nut on my electronic ignition was loose so I tightened it and drove down the road hoping for the best and everything seemed fine no more problem

Carquestions
Carquestions

Not likely a head gasket since you aren't complaining of overheating or losing coolant - given its age it could be lots of things - a tear in the diaphragm of the old fuel pump, fuel filter, points and condenser if it has them, carb adjustment of floats or a carb rebuild, bad coil or ignition wires, - these would be the most common for that year of car