The Stovebolt Site Forums The Shop Area Engine Shop Frequent stalling

My '59 Chevy Apache 31 has been sitting for about a year, and now I am starting a restoration. I took it to my mechanic, here's what he did:
New plugs and gapped
Set timing
New battery
New fuel filter
New clutch.

He put 9 gallons of gas in it and drove it about 48 miles. He had it idling for about an hour total while he was working on it. After I left his shop, I drove about 5 miles and it died on me. Looked at fuel filter, was bone dry. Put 5 gallons gas in, fired right up. Filled it up yesterday and noted the odometer to try and find out exactly how much gas I'm using (the sending unit needs replacing so I can't rely on the gauge). Had a new windshield and back glass installed this morning, picked it up and was driving home when it died again (after about 10 miles of driving). Looked at fuel filter, dry again. Filled tank, held 2 gallons. Fuel filter had gas again but it wouldn't start. Came back to it in about 30 minutes and shot Engine Starter in carb....it finally started up and ran fine all the way home.

It is really cold here today (about 12 degrees) so it's not the best driving conditions, but I'm starting to get spooked about driving it. I'm not smelling any gas while driving, but the gas mileage is figuring out at 5-6 mpg and it keeps dying.

Any ideas? Thanks!!!!

Someone put on an unvented gas cap?

The closer to full the tank is to full the smaller the air space and the quicker a vacuum forms.

The float valve is sticking closed and starving the carb?

Fuel pump worn?

Eliminate them one at a time.

I'm trying to follow your math on the gas mileage. A total of 16 gallons was added to the tank. The truck was driven a total of 63 miles and idled for an hour. Since your sending unit doesn't work, at no time did you know how much gas was actually in the tank. How can you figure out your gas mileage given all of this?
When your filter goes dry, you likely have a fuel delivery problem which is likely caused by debris in the bottom of the tank. If the chunks are large enough, they won't even make it out of the tank to be caught by the filter. The fact that your fuel starvation symptoms are intermittent also indicates fuel tank debris. The chunks move around from the gas sloshing around when you drive it or when you add fuel. I had this problem before. The truck would idle all day long, but if you increased the demand on fuel consumption (driving) it would stall like it was out of gas. At idle, enough gas was getting past the crud to allow the engine to run.

I'd agree it's most likely flakes in the tank, but it could be to do with the pump as well or as Jim suggests, a non-vented gas cap

Bill

I'd get a look inside the tank before you run anymore. If the tank is full of rust, dirt and varnish from old gas you are asking for bigger issues with your engine sticking valves and bending pushrods.

Thanks for the replies.....52 Carl, I know how much gas was used because I filled the tank completely full, measured the miles driven, then filled the tank again and saw that I had driven about 10 miles and had used 2 gallons.

I have a new gas cap.....will also get a new tank and go from there. Thanks!

Any explanations for the terrible gas mileage?

You have to much gas going into the engine. Maybe pull the spark plugs and see of they are black and sooty. It could also be a bad fuel pump and your filling the crankcase with gas.

Is the fuel filter after the fuel pump? (i.e. between pump and carb) -or- is it before the pump (i.e. between the tank & pump).

Does your fuelpump have the glass bowl and filter screen?
If so how does it look? Any debris visable in the glass bowl?

In a fuel delivery problem, 1st step should be to determine if fuel is getting to the carb which you have. Then work back towards the tank. Depending upon where your filter is located, could be the pump, lines and or clogging tank.
If there is clogging, there should be some evidence visable in the filter.

!'d make sure everything from the tank to the fuel fitting at the carb is good and that you have good fuel flow to it before tearing into the carb.

re. poor gas mileage. Once you get the stalling problem corrected you can isolate & correct the mpg problem.
My 216 w/a 1bbl Rochester finally got 13mpg on this last tankfull. It's been avg'ing 11.5 to 12.
It's only been running about 9 months or so w/approx 4k miles. Both mpg & power has steadily improved w/usage.
I expect it'll improve alittle more but I'm OK w/it as is.

If your engine has been rebuilt is should improve way beyond 13mpg but if it's worn probably not.

Good luck
Dave

2 gallons of gas in 10 miles is a bunch of gasoline.

and it's mostly not getting burned, look for wet spots everywhere

Bill

Ordered a new tank, new gas cap, fuel pump, and carb rebuild kit.

Volfandt:
Gas tank => fuel pump => fuel filter => carb
Fuel filter has glass or plastic bowl....no debris shown.
Engine has not been rebuilt.....valves were adjusted 2 years ago but it doesn't sound like it's missing out the exhaust....it's the standard 235 Thriftmaster

Move the filter in front of the pump. If its a mechanical pump the valves may not seat due to crud... you said there was a glass dome (aka pulsator) does it look like there is a fine white crusty looking coating in there? That's a sign that fuel and water have dried out and left the grit, and can affect pumping.

As mentioned... you need to look at your plugs. They will tell you exactly what's going on. Its one of two things... not enough or too much fuel. Are the manifolds tight? Is the heat riser working?

Before you rip out all the old.. hook up a vacuum gauge and pull the plugs.

pfarber - I don't see any crusty coating in the fuel filter, just gas.

I'll pull the plugs and report back, thanks

Have you pulled and smelled your dipstick? Make sure your mechanical fuel pump hasn't failed and the gas is going in the crankcase.

Also are you sure you're not losing fuel from a leak?

What's the inside of your tailpipe look like?

Don;

Where are you going with the tailpipe question? What should it/shouldn't it look like?

Tailpipe inside is black....some soot came off on my finger.
Pulled dipstick (truck has been sitting for 2 days). Smelled OK, maybe just a little gassy. I have sinus problems so my "sniffer" could be off.
Spark plug is black soot, came off easily on my finger.

P.S. Pulled dipstick again, it does smell like gas

The reason I asked about the inside of the tail pipe is because it will get black and sooty when its running rich. If the oil smells like gas you need to get it changed. Sounds like you have lots of parts coming. Good start.

As soon as the gas tank, fuel line, fuel pump, and carb rebuild is complete, I will get the oil changed and monitor it. Thanks!

Sounds like you are running rich. Soot in the tail pipe AND on the spark plugs means mixture is off... not 'flooding the motor' off, but enough to stumble off idle when you switch from the idle circuit to the high speed jets.

Personally I think your carb is off. I'd spend an hour or two with a vacuum gauge and a timing light to ensure that everything is set properly. Since nothing is wet the fuel pump isn't over pressuring the carb and flooding it, and that also means that the fuel pump is working. You have a glass pulsator dome so if you had a ripped diagram you could see fuel level go down.

If anything you will have a brandy new fuel system!

Yes, sounds like it. Along with the new tank and fuel filter, I ordered a carb rebuild kit, so maybe between all this, my problems will get solved. My mechanic set the timing a few weeks ago so I think I'm good there.

Parts should get here later in the week, may be next Monday before they get installed. Will keep everyone posted.

That is good to know about soot in the tail pipe. I'll add that to my bag of tricks and check my Burb as soon as I get home. Keep the great ideas coming!!!

There will always be some soot in the exhaust.... carbs will run rich during normal use (accelerating, using the choke, dirty air cleaner) so some soot is normal.

But if the plugs are sooty, then you have a real issue.

I'm amazed how some keep trying to split hairs and beat a dead horse all the time.
There is a big difference in what the tail pipe looks like on the inside on a vehicle running extremely rich vs. a vehicle that is in reasonably good running condition. Heavy black soot, to much fuel. If its black / grey and not wet looking its running decent.

I didn't have a soot level to fuel mixture ratio chart handy, so I figured I'd explain that soot is normal.

This is obvious:


Idles like crap, stumbles, heavy, visible soot out the pipe.

Not sure what 'wet looking' means. Water is the byproduct of combustion, so a wet exhaust means nothing. By 'gray' I guess you mean water vapor?

Tailpipes are full of soot. I've yet to know of a car that has a 'clean' exhaust... properly running or not. So by just looking at the tailpipe you cannot make an informed decision about the mixture of the carb. If you have devised some method (a certain mg/cm2 ratio? use a micrometer to measure the layer or soot?) please do share. I guess a good guide would be: if your exhaust looks like is out of a diesel engine then you might have a problem

Its all easily diagnosable by simply pulling a spark plug. That's the only sure way to tell whats going on with the mixture (short of an exhaust gas analyzer).

Don, hook, line and sinker. He didn't even use any bait. You of all people, should know by now that there is only one person who visits this sight that is 'right'.

Carl did make the 3rd post.. so we all should have just figured that was the only, unequivocal, non-debatable answer to all questions, ever!!

How dare we mere morals have a discussion, on a discussion forum.... please forgive us, do not smite us for our transgressions.. hahahahahaha

Will be interesting to hear the resolution.