The Stovebolt Site Forums The Shop Area Engine Shop Chevrolet 216 runs like crap. Need help.

Hello. I have a 1951 chevy 3100 panelvan with the original 216.
Last year i overhauled the original rochester carb because It was impossible to drive. It GOT i little better. But today i did the first testride this year and it ran like crap again Starts easy and idles perfect. But when i touch the gas it sputters and pops trough both carb and exhaust and dies very easely. If i Get It to run so i can start driving IT is very hard to keep IT running. But once i Get some rpm It runs better and respons a little better to throttle. But If i slow down and need some throttle in a hill or something it pops and shoots, But eventually starts to rise rpm🤷🏻‍♂️ Anyone have a clue? AS i said, overhauled rochester carb and everything new in the ignition.

Look down into the carb. throat while moving the throttle, fuel should spurt into the throat from the accelerator pump, if not, that would be a good place to start.

Ed

Ok i will check that tomorrow.
When i first started the car a couple of days ago after sitting for about 4 months, the carb overflowed with fuel, IT stopped after i knocked with a screwdriver all the way around it. Dno if this has something to do with it running like [censored].

Hitting the carb with a hammer causing the flooding situation to cease may indicate that the float may be contacting the casting nearby. It is pretty easy to bend those floats out of shape without realizing it.
Having said that, I will now illicit my "Its never the carburetor" mantra.
Popping from the carburetor and/or the exhaust upon acceleration is not indicative of a carburetor problem, but more likely a timing issue.
Either the timing is not set to specs, or something isn't right with the distributor internals, electrical or mechanical, or the timing gears.
The first thing that I would do is to verify that the needle is on the ball when the #1 cylinder is at top dead center.
Carl

Carl,

Like you, first thing I thought was timing is off.
Next thought is dirty fuel, tank etc. that might plug up fuel pump and carb.

What is the status of fuel (how old?), fuel lines (old or new), and tank (was it cleaned out, crud in it, etc.)? Do you have a fuel filter?

Chris

I will check the timing once again then:)

I used the car last summer. It did not run great then either But not as bad AS today.
The fuel is 6 months old. Original fuel hardlines But a new fuelfilter just before the fuel pump.

“Fuel is 6 months old”, corn squeezins or real gas? That could be your issue.🛠

Hi Devilsix,

I am still a newbie here, so please take this with a grain of salt.

So that said, have you checked for rust inside of your fuel lines? IMHO either ethanol fuel or the removal of lead from fuel caused rust inside of the hard lines on my ‘54. You did say “original hard lines” right. My hard lines were causing problems back in the early ‘90’s and every time I took the carburetor apart it was full of rust particles and yes I was running a filter.

And I know it is usually never the carburetor, but if you keep having problems with flooding, you may want to check to see if your float is leaking. If it is, you can easily tell by giving it a good shake.

Good luck,
Phillip

I had a similar issue with my 54 with a 235 . The truck sat at my camp and I started it up every so often and then I decided to bring it back to town 1 hour away so I did a tune up . It was running like crap after the tune up and could not figure it out there is a hill just past the drive and would backfire and pop .long story short was the points .

Slide a pierce of stiff, clean paper like a business card between the points, and see if any carbon or other deposits get transferred to the card stock. Also double check the point gap- - - -if the rubbing block wears it can close up the gap to the point the engine will barely run due to late timing. If the points check out OK, do a close examination of the wire running from the coil to the side terminal of the distributor. Since the housing is in constant motion from the vacuum advance, that wire can develop broken strands inside the insulation that effectively turn the ignition on and off as the distributor housing moves. I like to replace that wire with a piece of high-flex wire scavenged from a discarded voltmeter test lead.
Jerry

Looks like its time to give it a good look over...meaning looking all over it...sounds like carb problems to me. And old fuel is only contributing to da problem. If the needle and seat has a rubber tip, its probly crap. The accelerator pump sounds like its not working either. And i there are any rubber fuel lines spliced in, i bet the inside of em are disintegrating. See the common denominator, Bad fuel and rubber dont get along. Double check all secondary ignition, and if and when its all good. Dig into the fuel issue. If you have a ,"known good carb," drain crappy fuel, service lines as necessary, and try it. Dont over look a failing fuel pump either...Food for thought.. keep us posted. And good luck.

Old fuel can ofcourse be the problem.
But look at this video and tell me if you see a problem. Its me filming down the carb while running and giving some throttle.
The points seems to be in good shape.

I would also suggest adding a fuel filter just prior to the carb. either a clear plastic or a screw in type at the inlet. I have done this twice now, one prior to the fuel pump and one prior to the carb. If you have a glass bowl fuel pump, clean that out as well. There may be some floating or shifting junk in your gas tank too, I don't know if your truck has gravity flow out of the tank or a pick up screen and plumbing out the top. If gravity flow, pull the shut off fitting and see what comes out. If plumbed out the top, the filter on the end of the pick up could be clogged too. The fuel deterioration advice is good too.

I am going to sing my usual song here, and tell you that a Carter YF will make you life easier than the Rochester will.

Once you get it running , try some sea foam or top cleaner to clean out your system.

A compression check may tell you some things too probably should start with that, clean up the fuel system, and check the timing, points, distributor vacuum line and advance and clean the plugs.

Interesting. I would have thought there should have been a more consistent squirt of fuel.🛠
Is the vacuum advance working properly?

The accelerator pump only gives a squirt when you goose the gas pedal. It isn't a steady stream. Its purpose is to provide additional gas when you accelerate quickly. If you eased into the gas pedal while you drive, you won't get a squirt at all.
I am starting to think that bad gas is the culprit. In the video, when the throttle was goosed, it seemed like the accelerator pump was injecting fire retardant into the throat of the carburetor.
When I suspect bad gas, I use a small plastic outboard motor gas tank with brand new gas in it. The hose and squeeze bulb come in real handy as the hose is usually the correct size for your hard fuel line.
Carl

Last rebuild, the new accelerator pump leather was dried out and smaller diameter than the old swollen one. So I reused the old one and all is well. I wet that new one with a bunch of oil and put in a ziplock for next time, maybe it'll swell up to proper diameter. Believe if I'd used the new I woulda had same problems OP had.

I have used a hand sprayer for weeds with some clear line and a filter. You just pump it up and away you go. I even drove my truck at homecoming like that for my first drive!

Chris

Devilsix

I hope that you were able to figure out your problem(s). If not, I ran across a link from Old Cars Weekly that should be helpful to you and others in resolving this type of issue with our old trucks.

https://www.oldcarsweekly.com/restoration/pinpointing-carberator-problems

The experts in this Stovebolt forum (of which I am not one), have discussed most if not all of these troubleshooting checks at one time or another. This is just a handy link that combines much of what others have posted here and it appears to be in-line with the thought process of our sages. If not, I hope they will jump in with their expertise.

It is a rather long article, but the author covers several subjects just discussed here by the previous posters along with much more.

While the title is “Pinpointing Carburation Problems”, the author also states, “If the engine is not running right, the carburetor is the last thing that should be checked before blindly tearing into it. Ensure that compression is up to par in all of the cylinders, the valves are adjusted to their set clearances and the ignition system is operating properly. Often a faulty spark plug, wire, sticking ignition points or sticking, improperly-adjusted or leaking valves can mistakenly be diagnosed as carburetor trouble.” I believe that statement is directly in-line with what our experts here know from years of working on these old trucks.

In other words, it is never the carburetor until it is the carburetor.

Good Luck again,
Phillip

Thank you guys for all the help. I havent had the time yet to check anything But gonna check AS soon AS i Get time.

Just wondering of there are any v8 Engine that FIT on My three on the tree trans?
Im starting to lean towards Engine swap, But dont want to change trans and other drivetrain parts

I can't think of a V8 that would be a bolt-in swap on any stovebolt truck older than a mid-year 1955, when a 265 V8 was a factory option. Trying to install a small block Chevy V8 creates exhaust clearance problems with the steering column, and a totally different transmission, driveshaft and rear axle arrangement was used on the V8 trucks.

Engine room-wise, a Rover aluminum V8 would be a better fit, but lots of adapting would need to be done to couple it to the existing transmission and drivetrain. You would be far better off trying to find a 1954-62 235 or 261 cubic inch six. Those are almost a bolt-in fit without having to make any major drive train modifications.
Jerry

Ok, But if i wanted to swap to a v8 and different trans. What do i do with the rear END, and/or the torque tube? What do i swap that out with?:)
But hopefully i Get the 216 to run good enough to use

Concentrate on one thing at a time before letting your ADD/ADHD get the best of you like mine did. What happens in here is that it becomes one post with numerous side tracking things. Also, The search on here is your friend and can give you that info.

Chris

Yeah sorry. I tend to Get a little of course😂🤦🏻‍♂️ Will concentrate on the 216 for now

Timing seems to be spot on. New plugs with correct gap. Gonna try to install new points tomorrow and also adjust valves and also put new gas in IT and hope all this will help