The Stovebolt Site Forums The Shop Area Engine Shop Engine{235}won't start after new rochester carb.......

Frustrated that after purchasing a new Rochester carburetor and spending good money for the fuel tank to be drained and the engine to be inspected and prepared for the road the engine will not start. I was able to make 54 of the 56 mile trip home when the truck stalled at the third traffic signal coming into town. Towed the last 2 miles "Fred" is safe and secure under our carport. The 1952 Chevy 1/2 ton is restored from stem to stern. I can report that it ran perfectly fine on the 10 freeway at 50 MPH. I also stopped for gas and no problem starting.

I am open for suggestions as to how to trouble shoot the starting issue. You might have surmised I am no mechanic. I do believe this must be a quick fix as all systems were go when I picked up the truck.

An engine needs a few things to run, and diagnosing a problem starts with establishing whether or not those things are present.

Gasoline
Air
Spark
Compression

All of these things need to be there, and at the right time and quantity. Checking for gas is simple- - - -take the air cleaner off, and work the throttle linkage by hand while shining a flashlight down the top of the carburetor. You should see a stream of gas squirt into the intake as the gas pedal linkage is moved. If that does not happen, dribble about a teaspoon full of gas down the carburetor and try to start the engine. If it fires up and runs for a few seconds, you've found the problem. Find the source of the restriction between the gas tank and the carburetor. If you hold your hand over the carburetor throat and crank the engine, you should feel a considerable amount of suction, indicating the pistons are creating enough vacuum to draw air into the engine. That will also clear small pieces of dirt from the carburetor jets and allow fuel flow, at least occasionally.

If gas is present, check for spark. Pull the center wire out of the distributor cap and hold it about 1/2" from the engine block while somebody else cranks the engine with the ignition switch turned on. A spark should jump from the end of the wire to the block. No spark, take the distributor cap off, crank the engine, and see if the rotor is turning and the points are opening and closing. No rotor movement is a disaster- - - -mechanical failure to the camshaft, or the timing gears. If the rotor moves but the points don't open and close, adjust the points to provide a small gap when the shaft turns, about the thickness of a business card or a little more. Check for spark at the coil wire again.

If you've got gas and spark and still no start, you'll need to get back in touch with whomever did the restoration work. A compression test and a few other professional-level diagnostics are going to be necessary.
Good luck!
Jerry

Since the fuel tank was drained, this implies that the truck may have sat unused for some time. There was probably varnish buildup in the fuel lines, which could have moved forward.

If there is a fuel filter in the fuel line right before the carburetor, I would replace it. Once the fuel filter has been replaced, fill the carburetor through the carburetor vent.

And then try to start.

Jon.

Had something similar happen to me. W ent on a drive to pick up some stuff for the garden. About 50 miles round trip. Truck ran fine and all was good. It quit at the light 2 blocks from home. No restart. So I towed it home. Checked the fuel lines and fussed with it. Until I discovered the rubbing block was missing from the points. I had just replaced the points 2 days before. Points don't open and...truck won't start. It pays to be systematic as you work through the process. HRL has given you a good list of things to do. Check them one at a time. Test them one at a time and you will get it running.

Thanks from Palm Springs. Will be following your suggested steps Saturday.
Merry Christmas.
[censored] Bowman