hi ya'll. so i'm working on a 1951 chevy styleline deluxe, 216, 3 spd, pretty much all stock. so i thought i had all the bugs worked out but i guess not. i took it out yesterday to get some gas, about 5 miles round trip and i only put $10 in gas. it started right up with the choked pulled. once it warmed up it ran great without it. started right up after i put the gas in without the choke. i stopped off at my buddies and noticed a bit of oil leaking so i took it right home. it started right up without the choke and ran fine all the way home. inspection showed a leak at the valve cover which as it turned out, just needed to be tightened down. this morning i took care of the valve cover and deciced to make sure that was the issue by going on a short ride. the car started right up using the choke but would not idle. i figured it was just cold, restarted with the choke and found that it would only run with the choke and even with it pulled, it would run for a few seconds, sound like it was gonna die then run again. it sounded like it sounded like it was running out of gas. it would do this with the choked pulled but when it was not it would die. i it sounds like it is fueled starved. so here is what i have tried. took the carb off, checked the float level, increased the level by bending the tab on the float, oh yeah, its a rochester b single. that didn't help so i thought maybe fuel pump. its brand new but a china special. i tried a gravity feed set up, by passing the pump with a bottle hung from the hood. no change. i've also pulled the plugs, which are new, they were all fine but i cleaned and gapped them again, still the same. so what could it be? i did rebuild the carb as part of the "getting it going" process. any and all suggestions would be great. thanks
Is there a fuel filter in the carb? If not, did you bypass it when you gravity fed it? Kinda sounds like a clogged filter.
Restriction on the fuel line ( dirty clogged ) Plugged port in carb ? ( pretty basic carb but maybe ?) Vacuum leak ? Stuck valve ? (Possibly ) hook a vacuum gauge to it and see what it tells you.
Should run for a short time just on the fuel in the float bowl - you can fill it through the vent. If it runs rough with known fuel in the bowl, then it’s between there and the intake manifold - aka disassemble themcarb and clean everything up again. It’s often the culprit. If that doesn’t do it look upstream, such as filter, pump, etc. all the way back to the tank. Best luck to you and yours. john
Yep you've sucked up a piece of something. Have you tried to throttle it up by hand and throw a rag over the carb? Might help it suck whatever is clogging it up on through
What was the last thing you did while out ? You put gas in it . I would suspect the fuel first,,,,,unless you put good ole 100% gas in it . It was already up to operating temp before you gassed up,,,,so the new gas didn’t effect it . After it sat overnight and cooled down,,,,,and the new gas had time to infiltrate the old gas,,,,that could do it . Since it is starving for fuel,,,,,,ethanol will cause it to act in a similar manner. And just because the pump says 10% ethanol,,,,,there have been test where it had up to25% concentration at times . Also,,,,maybe the batch of fuel you purchased had some contamination,,,,,other chemicals or even a little water . Many years ago a good friend of the family accidentally put kerosene in his old Chevy truck . He realized it too late and already had several gallons in the tank He didn’t notice any difference at the time,,,,it was already warm and running . But after he shut it down,,,overnight,,,,it wouldn’t start,,,,,crank ,,,crank,,,,. It would finally start,,,but ran like crap until it warmed up,,,,,,he finally ran it out in a few days . who knows really,,,,,there is a lot of stuff in new gas now,,,,,because all the modern cars can compensate for bad fuel . I could be wrong,,,,but I suspect the fuel first . Tommy
I think gangrene nailed it. those old inline chevies were notorious for the intake to engine and carb to intake coming loose and causing a vacuum leak causing these symptoms. take a wrench and tighten Tom
Have you ever cleaned the gas tank? It may have years of crud in it. How about the fuel lines, are they rusty? They could have a pin hole in them.
You may want to hook up a vacuum gauge and see what readings are present. You mentioned an oil leak under the valve cover. Was this just prior to the problem? I had a similar experience with my 223 six and it turned out being the valves needed adjustment... the same reading I was receiving on my vacuum gauge. Good luck.
wow, thanks for all the replies! sorry i didn't get to them until now. so there is no fuel filter in the entire fuel line. i guess that may have caused the problem? in addition the whole line, tank, sending unit are all new. there was a intake leak but i changed the manifold gasket to the thicker one, can't remember the name but, another member of the forum suggested it a few posts back. i will check that the bolts are still tight. i was thinking a inline electric fuel pump if everything else checks out. it's still 6 volts. can i use a generic pump or will it need to be a 6 volt? once again thanks for the help!
If your running 6v it needs to be a 6v pump with the required pressure. Are. you using a Rochester B carb ? Somewhat known and problematic with the upper and lower housings warping and throttle shafts getting worn in the bores. Are you using the thick phenolic spacer ? Not sure , but I think you still need a gasket on both sides of it, it’s not a gasket but a spacer to keep the carb off the intake. if you don’t have one get a vacuum gauge cheap and good diagnostic tool. It’s also easy to check for loose bolts or a disconnected vacuum line. could you distributor be loose and moved loosing your timing ? Just a random thought .
so it is a b model, there is a spacer and a gasket between the spacer and carb, don't think the dizzy is loose but i'll check. kinda new to all this so can you tell me just what to check with the vacuum gauge and how to do it? thanks
I'd put this at the top of my list as far as things that are cheap and easy to check. Disconnect the fuel line at the carb and pump a bit of gas into a glass bottle or jar. Let it set overnight and see what settles out or floats to the top in the morning.
Are there any flex hoses in the line? If so inspect them very carefully for cracks or other damage. Those can also swell inside and stop the flow. Even the smallest little hole on the suction side will kill it. Have you tested for fuel pressure at the pump? Check the needle and seat assembly in the carb. If it has a Viton (rubber) tip on the needle it could be sticking shut. I've had a lot of problems with that in years past. I won't use anything but a steel needle. Pull the gauge sender/pickup out of the tank and inspect it. There may be a fine mesh screen on the end of the pickup tube. Check closely for damage. Check the float bowl on the carb for water. A very small amount will cause your problem. If you find any water at all put a bottle of gas line antifreeze in the (full) tank. Install an inline filter. If you can get it to run and stay running, lightly spray some WD-40 around mating surfaces that bolt together. Any change in engine speed will show you a vacuum leak.
well, thanks for all the info and suggestions, they were a big help. looks like the problem is solved. i blew out all the fuel lines and removed the carb and took it apart. i really didn't see anything amiss, but cleaned and reassembled it and the problem is gone so it may have been both or one but either way, its fixed. thanks for the help!
If it has the factory hose going from the pump to the line check it,that went bad on my 37 years ago.
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