Cadillac & LaSalle Club Discussion Forum

Cadillac & LaSalle Club Forums => General Discussion => Topic started by: D.Yaros on August 19, 2012, 02:25:26 PM

Title: Strange - To Me?
Post by: D.Yaros on August 19, 2012, 02:25:26 PM
While driving my '55 CDV yesterday, I had the unfortunate experience of running out of gas.  After adding fuel to the empty tank she would run for short time and then die.  It would run and accelerate in neutral, then it was as though there was no more fuel.  This happened repeatedly.  So much so that I feared I would completely run down the battery.  I ended up towing the car home.

Once back home I filled the carburetor fuel bowl through the fuel bowl vent and she ran fine, and stayed running.  It was sort of like having to prime the pump situation, but in this case the pump was the carb fuel bowl.

Anyone else ever encounter this type of situation? 
Title: Re: Strange - To Me?
Post by: TJ Hopland on August 19, 2012, 05:13:34 PM
Does a 55 have a 'sock' or some sort of screen in the fuel tank?   My first thought would be that when running it that low would have let what ever crud was in the tank get concentrated enough to plug the filter.  The new fuel + time + the tow rattling things around got it clear for the time being.    No sock then my theory is not very good because any other sort of filter would be less likely to un clog.   
Title: Re: Strange - To Me?
Post by: Dave Shepherd on August 19, 2012, 07:22:46 PM
Agreed on the filter in the tank, you should do a fuel pump volume test see what you get.
Title: Re: Strange - To Me?
Post by: R Sotardi #11719 on August 19, 2012, 08:29:50 PM
Sounds like the fuel pump is starting to go. As Dave said, a pressure  and suction test is in order. Problem is...volumn test( measure of amount of gas per minute) needs to be done while the car is in neutral without load on the fuel system in drive. There might be enough gas flow in neutral, but starvation on acceleration. Fuel pump test for pressure can be done while driving. That way a gauge will warn you of a glitch. Loss of pressure denotes a failing pump.  A drop in suction ( hooked up to the inlet side) will show a fuel line obstruction. Ron
Title: Re: Strange - To Me?
Post by: Walter Youshock on August 20, 2012, 09:15:04 AM
There's no sock filter in a '55.  '59 was the first year for that.  You could have a failing pump or crud is now getting sucked into the system since the fuel level was so low.

If you haven'r rebuilt the pump with new rubber that is impervious to today's fuel, now is the time.
Title: Re: Strange - To Me?
Post by: Caddy Wizard on August 20, 2012, 10:24:06 AM
Fuel pump is failing and you weren't really out of gas (but low).  The first time the car quit and you thought it was out of gas was just the first episode in your now ongoing symptom of quitting.
Title: Re: Strange - To Me?
Post by: kkarrer on August 20, 2012, 11:41:40 AM
I'm in agreement with Art and the guys about the fuel pump as the likely culprit.  It's usually the diaphram, but if you actually did run out of gas and this happened then the possibility of sediment in the tank is very likely and I've seen it many times.  Most recently a young guy caravaned with us as we drove to GN from Texas.  He had a new fuel pump and carb and even took an extra fuel pump, but he hadn't dropped the tank and cleaned it (1960 Eldo).  On the way out we stopped for gas every time the gauge showed 1/4 tank, but on the return trip, he got down to fumes before we fueled up and when that fresh gas splashed into the bottom of that grimy tank...
The eldo went about 5 miles down the road before it began to act like it was out of gas again.  Sediment was the culprit.  I think there's a small fiter or screen on or in that carb and there may be an in-line filter in the engine bay area.  Check them for sediment and then move on to the fuel pump.
Ken Karrer  1941 6227D coupe
Title: Re: Strange - To Me?
Post by: Walter Youshock on August 20, 2012, 11:56:34 AM
I actually had a rust embolism travel from the tank and get stuck in one of the valves in the pump.  That's when I dropped the tank, cleaned and sealed it and added an in-line filter back by the tank.
Title: Re: Strange - To Me?
Post by: kkarrer on August 20, 2012, 12:25:17 PM
Yep.  Fuel tanks, radiators, water pumps, and fuel pumps are just things that I routinely replace when I buy a "new" old car, unless I have documentation to the contrary. Belts and hoses are more easily checked, replaced, and backed up, but fuel tanks and radiators can bring a great road trip or just a quick trip across town, into a day waiting for a tow truck. You can back up a mechanical fuel pump with an in-line electric model, but that will do you no good if there's garbage in your fuel tank.  It sure cuts down on the trouble shooting time too.  When there's no question about fuel delivery you can move on to other things.
Ken Karrer 1941 6227D coupe
Title: Re: Strange - To Me?
Post by: D.Yaros on August 20, 2012, 12:29:59 PM
Thanks for all the responses.  I too thought of the in-tank filter problem, but as noted, they did not exist in 1955.

--  If it was crud in the line, why would it run fine after I manually filled the carb fuel bowl?

My inclination is to suspect the fuel pump also.  Shall do the flow test and see what that tells me, if anything.
Title: Re: Strange - To Me?
Post by: goofyhb on September 19, 2016, 08:19:42 AM
The very same happened to me this weekend and I stranded in a 3 mile long tunnel.
In my case I knew the fuel tank was clean and had no rust. I had done several trips without any issues. But Saturday suddenly I lost throttle response. The engine would only run in idle. My first thought was that the fuel pump would not manage to deliver enough fuel. The glass bowl did not fill up properly. But the fuel pump has its own little filter element. See picture from Parts List: Part 12.4112. This filter was blocked with rust particles. These must have been stuck in the fuel line between tank and pump for quite a while (years). After cleaning the filter I could drive home. I took a spare ignition coil (just in case) and went for a longer test drive, but the issue did not reoccur. After returning I inspected the filter again. It was still clean.
I allways thought the filter element in the glass bowl was the only fuel filter in the 1955. Now I know better.