Hey everybody. I've tried everything I can think of, so I'm hoping someone here has experienced this before or has an idea of something else I can try.

The winters are mild here so I drive my 1967 4 door cutlass year around. I bought it summer of 2009 with 47,000 original miles on it. It has a 330 4bbl and last summer it started acting up on me. When I start the motor, if I let it idle for say 30 seconds before moving I'm fine. But if I try to take off after only 10 seconds I'll get one or two hundred feet and it stalls. At that point I'm not seeing any gas squirt into the carb when I pump the throttle. I can crank the engine pumping the pedal, pausing every few seconds and in maybe 45-60 seconds (feels like 10 minutes when I'm sitting in traffic!) it will start and run just fine. That's the behavior. It doesn't do it every time, but maybe 1 in 15 times when I don't let it idle long enough before driving.

So the first thing I did was put a gasket kit in the carb with a new fuel filter. Drove for a while until it happened again then I replaced the fuel pump. That didn't fix it, so I dropped the fuel tank pulling the sending unit to look for clogs, used the air compressor to blow out the steel line along the frame and replaced the rubber fuel line. I thought that finally did it until tonight pulling out of the church parking lot... lots of traffic trying to get out and I'm stalled in the middle of it all Pushed the car out of the way and sure enough got it started a minute later.

What did I miss? It seems that the carb float bowl is going dry and it takes some effort to get it primed again. As I'm typing this I am thinking that maybe replacing the fuel filter again may not be a bad idea. If I'd known ahead of time what I would try, I should have started at the tank and worked my way forward. But the randomness bothers me.... it doesn't do it every time.

Please share with me any thoughts or ideas you guys may have. I really like driving this car but don't want to get stranded somewhere if it ever fails to re-start. Not to mention the embarrassment at being a "car-guy" and having my cool old car die when I'm trying to go somewhere.

 

John

first thing I think of is old lines as in the rubber being to soft...to much vacuum.. pinching the line closed?

 

Thanks Wes, I changed the rubber hose on the fuel tank and the ones before and after the fuel pump. I'll crawl underneath to make sure there's no other sections of rubber line. John

 

Maybe the float in the carb, or the needle valve. If it sticks in the up position fuel won't get in. Did you rebuild the carb or just gaskets. I assume a Q-jet. Just a thought.

Now I read all of your post and you mentioned float. Material in the carb that every so often clogs the needle.

 

This time are you sure it is still a fuel problem/dry carb? Maybe choke or choke pulloff is not adjusted properly causing the stall but if carb still goes dry that is a strange one. You have pretty much covered the bases with this one...

 

I would have to go with the float deal. I would take it apart and clean it out with some carb cleaner. My buddy had problems with his carb (it was an Edelbrock) in California due to the winter fuel mixture they use (yes, for some stupid reason they change the blend in the winter), the metal in his carb actually started breaking down and flaking off. Ended up replacing the carb body.

 

You might want to replace the needle & seat, along with the float. You may also want to switch over to an electric choke set-up. They are more reliable and easier to use. One other suggestion I have for you, would be to "T" into the fuel line where it enters the carb. Install a fuel pressure gauge there. That way you can verify whether you have a fuel delivery problem or a carb problem.

 

Thank you for the idea's guys. This will give me some things to try.
John

 

a quick look at a clear fuel filter at the time of stalling will tell also. its not the choke closing up on you?

 

I agree, splice in a fuel pressure gage, run it into the drivers area where you can watch it from inside. Then I would hook up a hand choke, so you can choke it when it stalls .

 

x2

 

Did you ever check the gas tank cap? Sometimes the vent hole gets plugged on a vented system and wont allow pump to bring fuel through the line. Sorta like a vapor lock -- but after a while when air seeps back into the tank it will re-pump the fuel and start.
About the suggestion to put a fuel pressure gage INSIDE the car? BAD IDEA!! Can u imagine what would happen if you spring a leak? Dont ever plumb raw fuel into the interior of an automobile! Keep any fuel pressure gage in the engine compartment!! - you can always look at to see if there is any pressure. Rebuild the carb is a good next step but the float is probably not the problem unless it is sticking in the "raised" position and not dropping to open the needle to let fuel enter the bowl. A good test of that is to rap on the side of the carb with a small hammer when it shows no signs of accelerator pump pumping fuel into the carb. If that float is stuck up --- the tapping on the side will shake it loose and fuel will then enter the bowl and will start agin. If your float is bad, and sinks, fuel will spew all over the place --- just the opposite of your situation!!

 

John,

Another possibility to consider is a collapsed fuel sock on the gas sending unit. I had a similar problem to yours, and after replacing my old gas sock with a new one, the problem was resolved. PITA to fix, Just a thought, & good luck!

Les

 

Les, I pulled the sending unit out of the tank and looked at the sock, but I was looking for dirt and crud plugging it which I didn't see. When you say collapsed, what would it look like? What was your source for a replacement sock? Changing that would be a pain, but if there's a chance that would fix it I'd be willing to give it a try!

Chesrown, The tank has two breather hoses on it and the foam filters in them were dirty, but didn't look completely blocked. I had thought of replacing them and should do that.

On two of the incidents I pulled the air cleaner and looked for fuel squirting when I pulled the throttle with my hand. There was no fuel, so that's why I suspected the float bowl was dry. I did replace the needle and seat with the carb kit. I didn't see any garbage in the float bowl when I took it apart. I've got a little brass hammer, I'll try tapping the float bowl next time it happens.

Yes, Southern Oregon also has oxygenated gas in the winter time and I don't know exactly what it does but have heard stories that its lousy stuff and causes problems.

 

I've no idea what to do to solve your problem; it's well documented that I do not work on mechanical aspects of our Oldsmobile's! LOL! Bory work I can do. I would suggest that once you have corrected the problem you might use some of the NEW Sta-bil BLUE (Marine -biu at your local marina, or Wally World has it; I not shop there, except for that) when you fill the tank. I keep hearing that it counteracts in some way the crap that they are putting in the gasoline mixture nowadays. Good luck on finding the problem!

 

I'm going to go with the stuck needle theory. It's easy to check as my '66 442 would randomly do this too. Force it to stall, then rap the carb with a small hammer and see if you can squirt gas immediately again. If you can, it means the float went down, but the needle stayed up. My plow truck is doing this right now too.

 

you meant well and have the right idea -- but actually if the float 'sticks" it is in the 'Up" position which has the needle on the seat (or closed). As the fuel is used from the bowl the float drops which RAISES the needle off the seat to allow more fuel to enter the bowl. If the float sticks in the "raised" or "up" position the needle stays on the seat and the fuel bowl runs dry as the fuel is consumed - hence "no squirt" from accelerator ---- If the problem is "stuck float" -- this is why the rapping with a hammer will jar it loose and cause the float to drop which inturn allows fuel to enter the bowl and then it will squirt and engine come "back to life"!! All science aside - bottom line is - if float sticking IS the problem ---the hammer tapping ploy success will verify that a "sticking float" is indeed your problem -- and now you can go in there and resolve it. May be gummy, or something bent in there a little?

 

All I could go by is the only carb I've ever worked with, the Marvel Schebler. It's needle goes up and gets stuck up while the float drops with the lack of fuel.

 

Like I said -- Same story - only upside down!! LOL - yud think gravity wouldnt play so many tricks on us - eh?

 

John,

Do you have another carb that you could switch with the one on there now? I would try a different one to see if that solves your problem. Then, if that is the cause, then you know the carb needs to be gone over again.

 

Darrell, swapping carbs may be the simplest way to eliminate the carb as a problem. I do have one on a 1967 425 that's in good shape, it should have the same choke and throttle setups. I like to troubleshoot things starting with the easiest thing first... and hope to find the problem quickly!

And knowing the gas at the pump isn't as good as it should be, a bottle of additive might be good insurance to reduce future problems. John

 

Is the float new or was it readjusted, a new float could have a burr which is catching (if it's a Q jet with the plastic float) or if it were readjusted the position could have changed slightly to cause it to hang up. When it happens again gently tap the carb with a tool. I had this happen on two Caddy's with Q jets and new floats. It worked itself out, presumably the burr or whatever was causing the float to hang up eventually wore smooth. Power pistons can also bind on a Q jet but that will usually just cause the car to run terrible.

 

When this quirk started the first thing I did was the carb. I didn't replace the float and didn't reajust it, but I did replace the needle and seat. So the problem could be with the float. We'll be getting rain all week so I'm going to have to wait until next weekend to tinker with it. Too much treasure (pronounced clutter!) in the garage for me to get the car in there! John

 

I know this thread is pretty old now, but I was wondering what happened.

I recently had a fuel delivery problem in my 66 Dynamic. To make a long story short the steel fuel line close to the connection at the tank had small rust holes, just enough to prevent a good vacuum from the fuel pump. I cut a suspicious section of the steel line and replaced it with rubber, and all is good.

 

As suggested by other guys it turned out to be the float. I replaced the plastic one with a brass one from NAPA and have had no problems with it since. Seems strange to me how it could one day just start sticking, but that was it!
John