Fuel system problem FINALLY solved!

[m-mman]

Over the weekend I finally solved a fuel system problem on my friend's 1960 Edsel wagon. (yeah I know not a Cad but this is still something to look for in your repairs)

The car had 10 years worth of 'fuel starvation' issues. New; filters, pumps, strainers, tanks, carbs, etc, etc, etc . too much time using the (useless) vapor lock words when the problem happened even on cold days.

It was intermittent and not consistently reproducible so after every repair or replacement I thought I had finally solved it.  <wrong!>

Well, I DID finally solve it!!!

The only thing not 'checked'(?) was the fuel line itself. It snakes over and around the frame so replacement without removing the body was not going to be possible. So how can you PROVE that it has a problem???

Easy, but only in hindsight. I plugged the metal line at the pump area. (rubber hose with a bolt in it) Then I went to the other end (at the tank) and attached the vacuum brake bleeder tool.

As I pumped it I COULD NOT draw down a vacuum (strange) AND the little jar began to fill with fuel . . . . .
This meant that, without a doubt, there was a crack(?) break(?) pinhole(?) SOMEWHERE between along the distance of the line.

A slow meticulous search revealed a crack in the metal line BEHIND a clip that held it to the frame <yikes!>  It was 8-10 inches back from the pump.

I cut the line, installed a new rubber hose from the pump back to that point, then returned to the tank and whattya know it held a perfect 20" of vacuum!! 

The pinhole/crack never leaked fuel, the frame clip was as dirty as any other (so it had not been washed with leaking fuel). There was never any indication of the loss of integrity beyond the intermittent fuel starvation issues as the crack opened up and sealed back again over the years from temperature and vibration. . . .

Diagnostic lesson? If you are having fuel starvation problems, vacuum check your metal line for leaks.

[chrisntam]

Great job!  and a great way to test for leaks.

[bcroe]

That works.  I have been known to reroute lines so I can access them. 
At the same time they are replaced with something that won't corrode,
and held in insulated clamps to avoid any galvonic action.  Bruce Roe

[Scot Minesinger]

On any 1979 or older classic car, if I am charged with making it safe and reliable, every portion of the metal fuel lines and brake lines, (plus rubber of course too) get replaced with new.  Generally you can get the exact same routing and you can replace them, however a splice in a few places may be required.  One time on a 1970 Cadillac was able to puzzle both gas lines into place after a few hours without splicing, but it only happened once.  Splices are double flare type using that Eastwood tool.  There are many other components that I replace too, similar to Bruce's list, this is just one of them.  It really spares headaches like these down the road.

[Steve Passmore]

Mr Crabtree, What were your symptoms?

[m-mman]

All the symptoms associated with 'running out of fuel'. Stalling, hesitation, quitting suddenly on the road

Hard starting - as a collector car it might be parked for weeks to months at a time. It always needed to have fuel poured down the carb to start AND then to have more fuel poured 3-4 more times after it had already run for 30-60 seconds after each priming. (how long does it take to draw fuel from the tank?)

The owner lost complete confidence (and love for the car) when he was returning from a cross county trip almost a decade ago. Summer yes, crossing the desert yes BUT every 20-40 miles it would quit suddenly. He would coast to the side (trying to find a shady spot under a bridge) wait 30+ minutes for it to 'cool down' and it would restart and he could proceed.

I had replaced all kinds of stuff IN HIS GARAGE and it always ran fine when I was done so I figured I had fixed it.

I got the idea to try reaffirm his confidence (and love) in the car by planning a 400+ mile trip at the end of this month. I had him drive it to my garage so I could check 'everything'. Yes the accelerator pump was bad and there was varnish on the throttle plates so I put a kit in the carb.

BUT I also spent time working with the charging system (it was charging at 12 v not 13.8v), Replace the thermostat (it had been removed) - flush & refill the cooling system and R & R the intake manifold to stop an oil leak which also necessitated R&R the distributor and resetting the timing etc.

Each of these other jobs required that the car run for 30-40 minutes while I messed with adjustments and stuff. Well, on three separate occasions the car just quit suddenly(!)    It would not restart  there was no fuel being ejected from the rebuilt accelerator pump. On Each occasion I filled the carb through the vent pipes and it restarted easily and continued to run and I made the other adjustments.

A fuel pressure test (made after sitting all night) showed 0-2 PSI when cranking. Work the accelerator to prime the carb and have it start, and the pressure stays at 1-2 PSI for 6-8 fuel pump cycles then it 'catches' and rises to 5-8 PSI with each successive pump (5-10 seconds with a running engine) And then it settled in and held pressure at 8-10 PSI and ran great for a long while. Maybe quitting again late in the day or the next day. It did this with two different fuel pumps!! 

These were the symptoms that kept me from sleeping and trying to work through a solution OR A TEST that would find the problem without the continuation of needlessly swapping parts. And I finally thought of vacuum testing the line. 

[WSS]

I managed a shop in KC several years back.  Being the lover of old cars that I am I would take on oddball cars that other shops wouldn't touch.  One was getting a 1951 Cadillac limousine in roadworthy condition.  The customer gave me a certain amount of $ to work with and to do everything I deemed necessary to get the car on the road as he intended to drive it a long distance.  I remember this car had the hydroelectric  power windows and was equipped with a manual transmission.  I thought how odd that for a limo to be ordered with a manual transmission and not the Hydra-matic.  I believe Hydra-matic became standard the following year
Anyway, after we "thought" the car was ready to be picked up I phoned the customer and he was to pick it up that evening after we'd closed.  The next day he called and said the vehicle quit on him a few blocks from our shop and needed to be towed.  We got it back and could find nothing wrong.  We even drove it around a bit.  Thinking it was just a fluke he picked it up again the following evening.  This time he made it about 30 miles and it quit.  To make a long story short, this happened about five times.  The owner was getting PO'd and I was embarrassed.  Finally I instructed one of the mechanics to take it out and drive it till it quits.  I also told him to immediately access whether it was getting fuel and/or spark.  He did so and determined the car was starving for fuel.
Now that we were clued in we found the fuel line had rusted through at the top of the "kick up" of the rear axle on the frame.  The split was under some sort of wrapping so no visible leaks were apparent.  We repaired the fuel line and never saw the guy again.

[Scot Minesinger]

It is really good that the problem was found, as you feel a huge sense of accomplishment when it is resolved - we all may have enjoyed this rich experience.  Replacing all rubber, and precautionary items is a great idea for peace of mind. 

[TJ Hopland]

Ya leaks on the suction side don't leak till its pretty bad.   One thing that can happen with a very minor leak is they seal when you get them under vacuum.   For those you have to try pressure which can take a little more to rig up.    You see minor air leak issues like that all the time on diesels, air in the fuel really screws them up. 

That was a nice thing about a carb you pumped it into a vented bowl so as long as you were getting more fuel than air you were fine, the air just burped out in the bowl.   Also a nice feature of the mechanical pumps, they pump air just fine.   Electric pumps for the most part don't pump air. 

[CadillacRob]

Just want to throw this out there guys, Nicopp (nickel copper) line material is available at most parts stores and flares and shapes very easily.  Most importanly, it won't corrode like steel, and it's DOT certified safe for brakes and fuel lines.  OEM on many euro brands.

[bcroe]

Nicopp (nickel copper) line material is available at most parts stores and flares and shapes very easily.  Most importanly, it won't corrode like steel, and it's DOT certified safe for brakes and fuel lines.  OEM on many euro brands. 

I have converted to that stuff for ongoing work.  Far easier to
use than stainless.  Get exactly what you want delivered, from
Ama++n.  Try to use rustproof fittings.  Bruce Roe

[35-709]

Where I am NAPA, Carquest (now Advance Auto Parts), etc., stock Nicopp or can get it for you overnight.