The Stovebolt Site Forums The Shop Area Engine Shop Give me a few things to try

I've got a '56 3100, 235. It runs good has nice acceleration, has HEI ignition and new fuel pump and new carb. The problem is it is difficult to start. Both when cold or warmed up. Even with a new battery it will spin the starter on and on without firing up. Almost ran it completely down after driving into town and stopping and starting three times. That third time caused me to stop running errands and head home. Where do I start? I expect it to be a little hard to start after it's sat for several weeks. But then to still be hard to start after driving into town (10 miles) doesn't make sense. Any ideas?

What type of carburetor do you have?

It's a new (made in America) Rochester. Not sure about that ("Made in America. ) part.

The next time you have a "hot no-start" condition, do these things.

First, look down the carb throat with the throttle held all the way open (engine not running, of course) and see if you have fuel pooled or pooling on the intake runner. I would do this as soon as you shut the truck off after an operating temperature drive. Then look again when you come back from buying celery.

If you see fuel or dribbling, your accelerator pump is most likely leaking.

If there is no fuel leaking or dribbling, look down the carb throat and goose the throttle manually. If you don't see a strong squirt of fuel, your accelerator pump isn't working.

I'll give it a try and let you know Otto. Probably be tomorrow. But to make sure I'm clear the engine will start it just takes several long tries. After several of those it starts. Hopefully before running the battery down.

What is the tag number of your "new" Rochester? How old is the fuel?

You have too many unknowns for an easy answer (non-original carb, non-original distributor).

If it were mine, I would enlist a helper.

Remove air cleaner on a cold engine.
Open choke butterfly about 1/2 way.
Have help begin to crank engine.
Standing back away from the carb, and wearing goggles, spray a stream of starting fluid past the choke butterfly for maybe 1 second.

Does it start immediately? If so, distributor probably OK. Try to find a worn-out original carburetor to try. Repeat the test.

Post your results.

Jon

There is no tag on the carb. The fuel is fresh. I've done that spraying into the carb before but not with this carb. I do have an older Rochester I can use.
Not having a helper is one of my problems.

If there is no tag on the carb and it is new, it is probably an import.

Try the older Rochester.

Jon

Finding a new "Made in USA" Rochester B 60+ years after they stopped being used on new vehicles is about as likely as finding an honest politician. That one was probably made in some offshore Asian sweatshop by virtual slave labor. You can solve the "no helper" problem with 6 feet of plastic tubing- - - - -stick one end down the carburetor throat and spray starting fluid into the other end from the driver's seat. In case you're experiencing a "hot soak" flooding situation, have you tried cranking the engine with the throttle held wide open?
Jerry

I prefer using spray choke cleaner over starting fluid, seen some bad results when the engine fires off with too much gusto, pistons get to the bottom & keep going.
Driven many a rig with failed fuel pump into the shop with a
spray can of carb cleaner.

I have been on the wrong end of an engine fire... Not Good! I don't use anything that volatile around an engine now days.

My 250 does the same thing, it has a time limit on restarting. If I drive 8 - 10 miles and run in to get my celery and come right out, it fires right off first hit. If I set and eat the celery, it cranks for way longer than needed but will fire off eventually. If I let set for a couple hour or so, it hits right off like a new truck.

I'm pretty sure mine is heat soak letting the fuel boil over into the manifold flooding the engine. The short trips to the hardware store is not long enough to really heat up the carbs, but 20 - 30 minutes does. I can see fuel residue running down the side of the block where it seeps out of the rear intake port gasket ( it all runs to the back due to the engine installed angle). I keep it wiped off, but last week it was 100* out and it was terrible to restart. I have insulating plates under both carbs, but it needs a fuel pressure relief return line to let the heated fuel go to the tank instead of the carb bowls. Thats my next project then I get time.

I don't notice any black smoke when it starts, but holding the throttle open while cranking seems to clean it out some. I have tried holding partial open, giving it more fuel, leaving it shut, nothing seems to help much other then just cranking it till it starts. I have a good working HEI and a new battery, 99% sure it over fueled related. I should look at the carbs when it won't start, just too lazy to pull the air cleaner lid.

Mine runs on the lean side, I also have a small catalytic converter that puts a lot more heat into the exhaust and holds it there. But, it runs great when it starts, doesn't smell, the exhaust is clean, it gets great fuel mileage, so I tend to live with it no more than I drive it. 250 inline six, dual Carter W-1 carburetors, HEI ignition, A/C.