1978 20R engine won't turn over it will crank but not start What could be wrong?

Answer 1

Always start with the basics. Do you have fuel? Is there some fuel in the carburettor? Do you have spark? Is it 'in time'?

Start by checking for spark. Remove one spark plug and place back into the spark plug wire boot. Place the electrode on a good ground (basically, any clean metal spot on the engine) and try to keep it from moving. DO NOT HOLD THE SPARK PLUG OR WIRE! The voltage and amperage is definitely enough to kill you. Make sure you have placed the spark plug in a good visible location with not too much light so that you can easily view it from the car while you cranking the engine. Another person does help quite a bit. Crank the engine. Can you see a good blue spark? If you can, replace the plug and move on to fuel.

After verifying there is fuel in the tank, check the carburettor. If you look down the body and open the throttle, do you see and smell gas? If so, move on to timing. If not, check the fuel pump and delivery system for problems.

On the bottom engine pulley there is a series of marks and a single mark on the pulley (harmonic balancer) itself. If you can't see the single mark, turn the engine over by placing a large socket wrench on the harmonic balancer bolt and, turning clockwise, rotate the engine until the single mark is close to the 0 indicator on the timing plate. These are hard to see on older engines. Once these to marks line up, make not of the number one cylinder spark plug wire (the first cylinder up front) and carefully remove the distributor cap. If the rotor under the cap is pointing at the number one cylinder spark plug wire, you should be ok. If not, it's time for, well, new timing. Check the timing assembly for failed parts and replace.

Answer

I forgot to install a power valve on my carb and this left a half inch hole in the metering block. This caused my engine to majorly flood. Fuel filled at least one cylinder and the engine become hydrolocked and the engine wouldn't turn over enough to notice-maybe one degree each time I turned the key. I burned up my starter and had to drain gas out of my oil pan. Even if you're not messing with power valves (they're not even an option on edelbrock carbs) a rich fuel mixture could allow excessive fuel to build up and pass through the cylinder rings and taint your oil so check your plugs for dampness or black conditions every so often.

An increasingly noisy ticking sound coming from your engine could indicate a lifter malfunction. I once had an exhaust valve lifter 'mushroom' where the cam makes contact with the flat end and the lifter wouldn't move up & down smoothly. This kept the exhaust valve from letting out the unspent fuel through the exhaust and the fuel had only one place to go: pass the rings & into the oil.