The Stovebolt Site Forums The Shop Area Engine Shop 216 Engine starting problem

Hello All,

I have a restored 1948 Chevy 3/4 Ton truck, with a 216 motor and a 6V system.

Before I received this truck, the previous owner had trouble starting it. He had it "Fixed" and it seemed to start and run really well. During the "fixing" he had used a 12V jump box several times. The truck transporter had also used a 12V jump box and even charged the battery with 12V.

When I received the truck, I put a brand new 6V battery, and a new starter motor in it. I replaced the fuel filter that was placed directly outside of the fuel tank.

I was able to start it right up with no problems. After I did the brake job, I drove the truck for 20 minutes, turned off the truck at a gas station, filled the tank, then started her up and drove to my house and around the block for another 30 minutes. It drove so smoothly! The engine sounded like it was brand new! I parked it on my driveway and shut it off. Later that day I decided to take my wife around the block and the truck would not start.

When I tried to start it, it cranked, I heard it fire then it immediately shut off. No amount of cranking and gas pedal would get it to fire again. I thought I may have flooded her so I left her alone for a few hours then tried again.

It cranked, it fired for half a second, then nothing. I decided to check the plugs because Tom Langdon had told me that 3 carbs on an Offenhauser is way too much fuel for a 216. I thought my plugs would be all fowled up. They were! So I replaced the plugs with new ones.

Again... Same result. I crank, it fires for a half a second and then nothing... I sprayed a little fuel into the center carb.. still nothing. I then tried my spark tester. It sits in series with the spark plug wire and the plug itself. When I crank I see the light come on in the correct firing order. I thought the light was awfully dim so I decided to replace the coil and condenser with new ones. Again... same result. I crank, it fires for half a second, then nothing. No matter what I do after that I get nothing. I must let it sit for a while before I can crank and get a quick firing...

I have the original single carb intake manifold. I am having it cleaned up by an automotive machine shop. I plan on replacing the 3 carb setup with a single carb setup. I don't want to do any of this until I get this car running again. I don't want to introduce more variables.

Any help getting this thing running again would be greatly appreciated.

Thanks in advanced!

From the images you attached that is a nice looking truck. It may not be the answer to your current starting problem, but I think Tom is right. I'd put the original manifold back on, use one of the Rochesters on it until I could find one of the Carter models designed for the 216. Could have been model: 756s, 787s, 964s, 965s or maybe 2008s.

I would lean more towards a fuel delivery problem. Dirty tank, plugged feed line, bad fuel pump, clogged filter, pump to carbs line clogged. When it initially starts it’s on fuel that has seeped by the blockage and when it’s gone the engine dies. Sit awhile and a little more gas makes it to the carbs and again momentarily fires. Just an idea for some things to check.

I concur with Jon.
Also, do you have one of those really big (0) ground cables on that 6V system? Was it charging OK when you took your 20 + 30 minute drive?

Just a thought here, but if you made a pair of sheet metal covers to cover over the carb intake for the end carbs (bolt the carbs down over the covers), plug up the fuel lines to those carbs and disconnect the linkage to those carbs, you can use that manifold as a single manifold. Now you are running on just one carb and that may help you get your issue isolated a bit better.

If this was a fuel delivery issue, why wouldn't it start if I spray a little fuel directly into the carbs? I would imagine that would get the truck to run for 30 seconds or so..

I do have 0 gauge wire for ground as well as to the starter. It seems to be charging very well. It also helps that I keep the battery on a trickle charger too...

I will check the fuel system. I will disconnect the fuel line going to the carbs and see if my fuel pump is pumping fuel when I crank the motor. I expect to see fuel pumping... That way we could at least cross the fuel pump off the list.

As for the fuel itself... it is very clean and fresh. The tank looks brand new. I be this restoration was done a year or two ago... Again, the truck fired up and ran with no problem or struggle.

It should start for a few seconds, Gig. I'm telling you something you already know, but there are only a few elements to worry about...gas (is it getting there?), spark (is it happening all the time and is it happening at the right time?), and valve timing (which if you have been running the truck already and if nothing blew up or made any sort of odd noise like a camshaft gear disintegrating should still be fine). Mike is right in that you can cover two of the carb intakes and plug up the fuel lines. But may as well go ahead and use the stock manifold since you have it.

As for spark happening all the time, I mention this because I've been stumped before by a failing ignition switch and also by a messed up wire going to the coil (bad connection which made contact off/on). You can't see these problems and sometimes you don't consider them. The wire in my case had broken inside above where it connected to the end which connected to the coil and I almost never found this. I believe it was still making contact but it wasn't a good contact any longer. The ignition switch had simply worn out. The contacts were making connection sometimes fine and other times very intermittently. I discovered this when I was able to wiggle the switch sometimes and get the thing to start. Have you contacted the prior owner to see what he did and how he "fixed" it? Pull your plugs when it won't start and see if any are wet with fuel. You'll know you're not getting spark consistently that way. You'll also know you're getting fuel.

Oh, by the way I looked on eBay and there is a Carter 965s carburetor for $175 plus shipping. It is the automatic choke model (didn't find any of the manual models yet), and it is incorrectly listed as NOS (whereas it is actually rebuilt). However it does still have the ID tag and it looks nice. I've sent the seller a note suggesting he correct the listing and I suspect he will. I've actually dealt with this guy in the past and remember him as being ok. The auction number is 253840982247

Try this when you go to restart after running it for awhile.
1) While cranking, slowly depress the throttle all the way to the floor.
2) IF it doesn't start after 3 or 4 times as it turns over,
3) slowly let the throttle pedal up while still cranking.

If it catches and starts try to remember what position the throttle pedal was at when it started.

What you're trying to accomplish by doing this is to vary the amount of air fuel mixture while cranking to a point that it'll start. On my single carb'ed 216 I have to use this method to restart just about every time. I use my toe to depress the stomp starter and my heal to depress the throttle pedal. It's not as hard as it sounds LOL....

Many times when these old engines shutdown they'll heat up the fuel in the float bowl(s) which boils over into the intake. This causes an overly rich condition that a warm engine doesn't need for restarting. If you're trying to start with the throttle closed at the idle position you're making it richer by restricting the air flow to the cylinders.
Slowly opening the throttle to wide open increases air flow which helps to lean it out during starting. Flooring the throttle hard during cranking results in squirting more fuel into the engine and this is not what you want.

All this may be moot as you've got 3 carbs where only one of them is needed to provide good performance. It does look good tho.

One of the easiest ways to diagnose a problem between ignition, and fuel is to simply hook up a timing light. I found out the no start on my 216 right away when the light didn't flash while cranking. It was the points. You can even rig it up to check while driving with intermittent problems putting the light inside the cab. Same for fuel pressure, but not inside the cab. Ethanol fuel can do crazy stuff too.

Thank you for that! I am looking at the carb right now! Why is this one better than what I already have? Will this one work better? Or is it purely for aesthetics / correctness for my truck?

Well... you guys were right! The fuel pump diaphragm failed! I have a new pump ordered and on the way! I should have it Tuesday! In the mean time, I will take it apart and clean out the lines, drain the tank, and replace the filters.

Gig, Good to hear you found the trouble!
As a related thing, last year in my 63 stepside, the fuel pump suddenly failed. It was bought from
one of the classic truck part supply catalogs, don’t remember which one.it wasn’t very old at all.
Well, I opened it up expecting to see failed diaphragm, but instead one of the two check valves had
fallen right out of the hole it apparently was pressed into. Won’t pump that way, of course.
This has made me very uneasy about buying and depending on after market parts, which seem to vary in price a lot.
Well, I did a makeshift replacing of the valve in its hole, put it back together and it works, but.....
So I have an electric pump installed parallel to it ready to switch to, and while the truck is parked for the winter I’m
trying to decide what pump to order and how to know if a part is good quality or not before ordering.
Perhaps I’m missing an already existing discussion here on the forum.
But, again, I hope you’re troubles are over, and she starts and runs good!

Thanks for the update. Good to know I still can provide useful information occasionally. Hope you were able to find a quality pump.🛠

Hi Gig,
It isn't for aesthetics nor period correctness. The Rochester is what would have come originally on the engine. The two carburetors are different designs and certain factors in the Carter might be more appealing. The idle system is different, the cruise system is different and the power system is different if you compare the two. Some people think the Carter will work better and have fewer problems, but in fairness there are a lot of people who are fans of the Rochesters and lots of them are still in use. There are some challenges in them, and actually I'm working now to try to solve one of them. There is a ton of information here about the whole Rochester v Carter thing. There isn't any rush but sometime you might want to read through some of it and that way you can decide what makes the most sense to you.

Hi Jon G,
Thank you very much for explaining that to me! If I get it, how would I set it up?
I am not a carburetor expert, not even close! All those needle adjustments make me nervous.
Do you think the truck would start after bolting it on? I am sure there are plenty of
Instructions on how to set it up, could you point me to a link? I would love to conquer my fear of carburetors!

Thank you all for coming to my rescue! You all are really educating me! I can’t wait to share this with my boys as they get older!

Thank you!

Carburetor adjustments are simple- - - -always have been, always will be. People who say otherwise need to come talk to my garden in the springtime and I'll save a bundle on fertilizer costs. There are two adjustments on a stovebolt carb regardless of what brand you're working on- - - -idle mixture and idle speed. The idle speed screw is the one that speeds up or slows down the idle- - - -it's on the lever that moves when you step on the gas, or maybe on the carb housing next to that lever. Turn it clockwise to speedup, counterclockwise to slow down. If you're got a digital watch, get somebody to explain the CW/CCW concept to you! Set the idle speed somewhere in the 500-700 RPM range. Doing it "by ear" right now is fine- - - -we just don't want the engine stalling or racing.

Now- - - -idle mixture- - - -that's the screw sticking into the carb body near the bottom. It's a short screw with a spring around it, and nothing near it is going to be moving. With the idle speed set somewhere near "normal" speed, start turning the mixture screw clockwise until the engine slows down, stumbles, or tries to stall. Back the screw up until the engine runs smooth and steady. Go just a bit further CCW (maybe 1/8 turn). readjust the idle speed if necessary to get the best idle speed and smoothness.

It takes me less than a minute to adjust most carbs, with NO test equipment whatsoever. If you've got a tachometer, a vacuum gauge, and maybe a 4-gas exhaust analyzer, you can charge your customer a whole bunch of money to do the same procedure I just described, and impress him/her with your alleged "knowledge" of carburetors. Tuneup "specialists"have been using procedure #1 for as long as I can remember, and getting just as good results as the guys do who have a shop full of equipment. No external adjustments on 99% of the carbs out there have ANYTHING to do with high speed mixture or gas mileage, no matter what the self-styled fuel system gurus claim!
Jerry

Jerry, I think I love you man! 🤣

Now I feel like I can get that new carb on eBay that Jon suggested!

What do you think about it? EBAY item 253840982247

Carter's slogan for many years was "The ABC's of carburetion- - - -Always Buy Carter!" That's the right carb for your engine, the price is right, and it's an automatic choke model. What's not to like? My father, whose shop in Nashville was a factory-authorized service center for Carter through the 1940's and 50's, used to say "Automatic chokes and automatic transmissions are smarter than all drivers and most mechanics!" He was a very wise man!
Jerry

Thank you for making that decision easy Jerry!

Thank you Jon for recommending it!

I just purchased it! Now what do I need to do for an air filter and housing?

Anything but one of those tiny chrome ones. Get the part in hand first and do some measuring. Looking at the pictures of the carb, it looks like the original equipment oil bath filter should be a drop-on fit, or that same housing can be converted to accept a modern paper filter without a lot of effort.
Jerry

I just got this one Jerry! It is an original Chevrolet, non oil bath, air cleaner assembly.