VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 Fuel supply issue on 1929 Buick Engine

Hi, all. I am a career Firefighter at China Grove Fire Dept. in North Carolina. We own a 1929 American LaFrance Engine that was the first truck our station (which as founded in 1924) ever purchased. It has a Buick Stovebolt Six (I believe the 194)and a 3-speed transmission. We had the truck restored around 10 years ago and have had a few minor maintenance services since then. The truck spends most of its life in a climate controlled bay which is separate from the in service truck bays. This engine is now used mostly for parades and at public events as a show piece.

I have driven this engine about 4-5 times this year and have had no issues with it until yesterday. I drove the truck to a parade a distance of about 10 miles and then I turned the truck off for about 45 minutes while I was awaiting the start of the parade. I then drove it through the parade route (about 4 miles) and then back to my station. during the parade, The truck began having random misfires with a pop from the engine bay and the exhaust. It only did this a few times so I thought nothing of it, but on the way back to my station while cruising around 30-35 miles per hour, the miss became much worse to the point where it was almost constant and I was losing almost all power. I pulled the truck over and the engine stalled. Upon inspection I noticed that the fuel bowl beside the pump had air bubbles that seemed to be coming from the bottom, rising to the top, and the fuel filter had no fuel running through it. I also noticed that the cap seemed to be harder to take off than it should be. I'm not 100% but perhaps the tank had vacuum in it. After allowing the truck to sit for about 20 minutes while my Chief came to meet me, we were able to get the truck started by removing the cap and using some starting fluid to start the engine. Once the engine was restarted, the fuel filter began to have fuel flowing through it. I then put the cap back on the tank and continued on to the station. The truck continued to have missing problems on the last mile or so but I was able to get it back to the station just as the engine stalled. Once I had arrived, I saw that once again, the filter had almost no fuel in it.

I'm hoping that someone here can assist me in resolving this issue quickly because I need to have this truck ready for upcoming events.

Perhaps there is a venting issue with the fuel tank causing vacuum in the tank thus the pump cant supply fuel to the carburetor? I do know that the small hole in the fuel tank cap that should prevent this is clear of any debris.

My chief also was asking about adding an electric in-line fuel pump to feed the mechanical fuel pump bowl. Would this be at all helpful?

Any input is greatly appreciated!

Link to diagram of the issue
1929 Buick Fuel Pump

Not sure why the link to the picture isn't working properly in the other post...



http://s1110.photobucket.com/user/Speed4341/media/snipfuelpump_zps3f98ee21.png.html?sort=3&o=0

Hi Cameron ,
Welcome to chevy Chatter.
I tried your link but I could not get it to work. The advice here by most about fitting an electric fuel pump is don't. Too many cars have gone up in flames due to fitting an electric fuel pump.
I would think about maybe blowing out the fuel lines with compressed air as a start , and then checking to see how much fuel flow and pressure you get.
I am sure others will also be answering here, there is a lot of knowledge here.
Good luck with the truck.

Yes the link works now.

Another question I would ask is in your diagram the arrows pointing to the fuel filter. What type of fuel filter is fitted, is it an aftermarket type.

I believe it is a general aftermarket type inline filter.

here is exactly what I'm working with

http://s1110.photobucket.com/user/S..._555_zps054bc4dd.jpg.html?sort=3&o=0

http://s1110.photobucket.com/user/S..._743_zps0c75736e.jpg.html?sort=3&o=1

Sometimes there is concerns about fitting an aftermarket fuel filter due to the low pressure of the fuel pump.

Have you done any work to the fuel pump at all. The original diaphragm can deteriorated due to age , and incompatibility with modern ethanol fuel.

It has been running fine with that style fuel filter since we had it restored and we always used a fuel additive that stabilizes the fuel and makes it safe for engines that were designed for leaded fuel.

So you seem to be leaning towards an internal fuel pump failure. Its that correct?

Also, I did start the truck today and pulled it outside to clean its bay. It seemed to be fine today but then agian, I only drove it out and then drove it back in once I had finished cleaning.

How much pressure should this pump create?

Just as an FYI, I'm 24 and really good with modern day vehicles. I'm good with fuel injection/direct injection and computer controlled vehicles and reading PID's, Fuel maps, knock tables, etc. Heck I have a 2008 turbo 4 cylinder car that I've been working on and it makes over 400 lb/ft of torque and about 365 hp, BUT my experience on carburetors and older vehicles is pretty limited. Hence, why I came here looking or help. lol

Sent you a PM Cameron,

Mac

Are you sure you are using fresh gas without ethanol added? The chance of being in trouble when you use the engine so few times during the year is high enough to have it in mind. The ethanol will "collect" water and rust the surface inside the tank during long stays without running the engine.

Ethanol can also "eat" the metal in the carburetor, rubber hoses and glass fiber, making the waste passing on to the carburetor and stop there, unfortunately creating a possible risk for fire or overheating the engine.

Read the forum below and may be you could find a possible explanation for the trouble:

https://vccachat.org/ubbthreads.php/topics/267182/Warning_Ethanol_mixtures_must_#Post267182

I am using fresh gas and I use an additive for the ethanol/ unleaded gas. It also has a fuel stabilizer.

thanks for the info.

Maybe remove the neddle valve ahead of the fuel bowl and see if there is dirt in it.

Hi Cameron,

From the way you described the problem, it sure sounds like the gas tank is no longer being vented to allow air in to replace the fuel being drawn out. From the 1929/30 repair manual:

"In order that the gasoline will flow properly to the carburetor, there is a small hole in the top of the filler cap on the tank, so that air can enter as the quantity of gasoline in the tank is decreased. It is essential that this hole be kept open."

I would check the gas cap to see that it is vented. If not, this could be the problem and would also be an easy fix. I also agree on NOT fitting an electric pump. It worked before without one, so you don't need one now.

And like Jack said, welcome to Chevy Chatter.

Happy Motoring,

Dan

Speed4341, I thought you might be interested to know that we also have a forum here dedicated to (chevy) Fire trucks. You
can click on this link to take you there.
https://vccachat.org/ubbthreads.php/forums/30/1/Fire_Trucks

Even though the small hole in the cap is open it could be plugged internally. If the fuel filter has no sediment in it causing a shortage of gas then the cap seems the likely culprit. I'm not sure on fuel pressure but I'm thinking it should be around 3 to 3-1/2 lbs.

Speed,
I would guess that either a piece of crud is blocking the flow of gas from the gas tank to fuel pump or the gas cap is not properly vented (or vent is plugged). If it quits again quickly take off the gas cap and note if there is any sound indicating air being drawn into the tank or the tank returning to its original shape from being partially sucked in.

A piece of crud blocking the pickup tube in the gas tank can be harder to diagnose. The best indication is that the problem will be intermittent and not occur at approximately the same time based on mileage or speed (or both).

I also advise against adding an electric fuel pump unless it is intended to be and auxiliary to the mechanical pump and does not restrict fuel flow from the tank to fuel pump.

I just let the truck run for about 15 minutes but nothing happened. I'll take it for a drive tomorrow to see if I can duplicate the problem. I also checked the fuel lines like one of you suggested and they are steel lines from the tank to the carb so no chance of those sucking in.

Hello Speed4341,
You mentioned air bubbles in the fuel within the glass fuel bowl. If there was fuel starvation, you might be out of fuel and sucking air regardless of what the fuel gauge reads, or, it is possible that air might be pulled into the bowl from around a deteriorated glass bowl gasket. I notice a fuel shutoff valve installed before the bowl, there may be issues within if rubber is involved. If problems continue, drain fuel tank if there is a drain and blow out the fuel line. With not having a filter in the line before the glass bowl, check for debris at fuel inlet to glass bowl. Clean fuel cap vent and test to verify proper operation. Good Luck and don't smoke.