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Fuel Problems

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aroostok

Jedi Hopeful
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Have had my 76B up and running and yesterday following a funeral I did (I'm a UM pastor) I came out and when I started up the B it started screaming like a loose fan belt (it was fine up to that point). Went about a mile and the Blessed Virgin Mary started coughing and spitting and finally just shut down. Couldn't get it started, even jumping. Finally had to have it towed (really wanted to do another funeral on PA 944). Checked battery and it was only putting out five volts. Recharged and checked alternator and tightened belts. After a little coaxing started up and ran fine with all electrics running. Getting good output from alternator (14+ v) and battery checks good. Shut off all the electrics, went in the house, came back outside and BVM started sputtering again idling, and finally died. Checked battery and getting good volts. Pulled off fuel line before filter and I'm getting no fuel being pumped up to carburetors (2 HS4s). Have noticed that fuel pump has been running like it was going to a race (probably ticking a couple of times a second - seriously). The fuel pump is an after market electronic and don't even have 300 miles on BVM since completely rebuilt (including engine). Any idea where I ought to start looking? Could I have a fuel line block somewhere. I plan on checking the fuel pump coming out of the tank area tomorrow. Any help would be greatly appreciated. Thanks
 
Sounds you have a good idea where to start checking. if fuel isn't making it to the carbs, then obviously the car won't run. The next step is to figure out why the fuel isn't flowing. One of the following things may be causing the blockage:

1) A kink in the fuel line. Check the flexible and hard line bits. The flex line should be as straight as possible to reduce the likely hood of it crimping upon itself and cutting the fuel flow. Sometimes it won't kink itself until the tank runs completely out and refilled (happened to me in rush hour traffic after dark... that was a fun drive home!).

2) There may be something in the tank that's blocking the pick up. Some of the stranger temp fixes for this condition are to blow into the fuel line under the hood with the ignition OFF, and to bounce the car a bit.

3) a bad fuel pump - just because it's new and ticks doesn't mean it's good.

I'm sure there are some other people on here that can think of other reasons for the fuel to not flow.

Anyways, like I said earlier, it sounds like you have a good idea on where to start looking. I hope these thoughts help out in some way.
 
Thanks. Only question is should the pump be ticking as much as it is. I seem to remember from my daughters VW rabbit that it would do that only when it got REAL close to the tank being empty. I guess that maybe means I may have something in the tank blocking the line.
Thanks
 
Sounds like you have 2 problems simultaneously - battery drain and fuel pump problem.

Is it possible your pump is draining the battery?

Just a thought.

Also, if you have a private-label branded facet pump (molded black plastic outer casing) these pumps were designed to operate with a return line to the tank, even though they don't say so on the package. I went through 3 of them before I switched to another pump.
 
depends on the pump really. I have one of those 'electronic' fuel pumps that never stops and sounds like a jack hammer when it sucks air, but the speed at which it 'pulsed' was approximately twice as fast when the flex line from the tank pinched a while back.

so like you seem to suspect, there may be some sort of blockage between the pump and the tank, if not in the tank itself.
 
The fuel pump I have is, I believe, just like "eschneider" describes. Can you tell me what you replaced it with?
Thanks
 
hmmm... interesting information, because i've been running with one of those Facet type pumps for about two years now. I can't say that i'm entirely happy with it, but it seems to be working for me so far.
 
Ronald - If the electronic pump you have is one of the Facet pumps (little square, run all the time, make a lot of noise), it is normal for them to run all the time. They will run faster, if they are sucking air or slower if the fuel flow stops for some reason (including when the float bowls are full), but regardles of the situation, they keep ticking away. See my article on Fuel delivery troubleshooting at: https://www.custompistols.com/cars/dave/ddFuelDeliveryTroubleshooting.htm
for tips on isolating your problem (note there is a section on the pump running all the time, but not delivering any fuel. This is written to the SU fuel pump that shuts off when the float bown is full, but the information on looking for an air leak on the inlet side of the pump is still applicable, just keep in mind that if you have the Facet pump, you can have good fuel delivery and the pump will continue to run). A very likely posibility in your case is a plugged pickup tube or screen in the fuel tank.
Cheers,
 
Just filled tank - lots of gas.
Blew air back through line at filter connection and car started right up. Seems pretty obvious that I've got crud in the tank that's fouling the lines at the pickup. Since it's 30 years old should I consider a new tank?
 
Heck no. if it is not a leaker it can be cleaned. They are not difficult to pull and almost any radiator shop can boil em out for you, not expensive either.

Now to finish the job right check on a price to have the tank lined as well. Then you have a fresh tank without rust, etc. about 125 bucks in this neck of the woods.
 
If you have hte tank sealed, make sure that the sealer is compatible with today's fuels. I used aircraft slushing compound to seal the tank on our TD when I restored it 25 years ago. This summer the new formulation of gas available started desolving the slushing compound and I wound up with needle valves in the carburetors glued shut and the check valves in the fuel pump glued shut. Not fun.
Cheers,
 
If the original tanks lasted over 30 years, without being coated inside,(my tank is 34 years old and is perfect inside), Why would you want to go to the trouble and expense to have a new tank coated inside? Outside, yes, but inside????? Also, my car sat in my barn for over 15 years and never moved. If my tank goes bad, Ill pull a couple of bolts and put in a new tank and 30 years later, I might do it again??? But, 30 years from now, my kids can worry about it! /ubbthreads/images/graemlins/rolleyes.gifPJ
 
[ QUOTE ]
If you have hte tank sealed, make sure that the sealer is compatible with today's fuels. I used aircraft slushing compound to seal the tank on our TD when I restored it 25 years ago. This summer the new formulation of gas available started desolving the slushing compound and I wound up with needle valves in the carburetors glued shut and the check valves in the fuel pump glued shut. Not fun.
Cheers,

[/ QUOTE ]



There's an unintended consequence of using ethanol as an oxygenate in motor fuels. I understand that some boat owners are having difficulty, too. Unfortunately, I think the choices are to recoat tanks with compatible materials, buy new or go to the airport for 100LL avgas.
 
If you do not have an issue with the inside of your tank do not coat it. Only if you have some pin holes or rusty spots inside. Clean and use filters.
 
[ QUOTE ]
The fuel pump I have is, I believe, just like "eschneider" describes. Can you tell me what you replaced it with?
Thanks

[/ QUOTE ]

I would recommend replacing the black plastic facet pump with a "genuine" metallic square facet. Best price I've seen is $40 from pierce manifold. Moss sells them for something like $90.

sounds like this isn't your problem, though.

you might make sure your tank vents haven't become clogged. You can try running it without a cap (if/when the problem reoccurs) to test that theory.

also check to make sure the fuel lines arent cracked between the tank and the pump. I recently had one that was sucking more air than fuel through a cracked rubber hose.

I might get flamed for this, but I love clear plastic fuel filters to check for tank gunk. my favorite is wix # 33011 - napa or carquest should have 'em.
 
No 'flame', Eric, just my opinion: I prefer the 'tin' ones tho have fitted plenty of the plastic variety too... If there's a suspected problem I could see putting a plastic one on for a while just to monitor things. The really scary one is that li'l glass cylinder number. That one has much more potential for nasty consequences.

...I'm the one likely to be flamed now. /ubbthreads/images/graemlins/devilgrin.gif
 
yeah, I agree with you - the glass filters are the root of all evil (next to country music and small yappy dogs). They leak and don't do much filtering. And I certainly respect that metal filters are more durable than plastic.
 
heh... with that country music comment I fear the "flameball" is back in your court. /ubbthreads/images/graemlins/devilgrin.gif

I've a Facet "cube" on our B and it's been reliable for over a decade. I've a number of SU pumps on the shelf, but why bother to replace what works?! I do have an 'on-board spare' SU just in case. Thinking about a full-blown dual pump setup, just as a useless exercise in redundancy.
 
Doc - I do hope that "on board spare SU" is an all electronic type. If it is a points style SU, it is almost a sure thing that it won't work when you need it. The tungstun alloy used for the contacts film over when the pump is sitting idle. For short periods of time, this is not a problem, because when the pump is run, the arcing of the points will burn the film off. Left idle for long periods of time, such as sitting in the trunk for years, waiting for the primary pump to falter, the film builds up to the point were it acts as an insulator between the contacts and the pump doesn't work. this is why I recommend the Facet or other brand of electronic pump be used as the permanently installed back up pump in my article.
Cheers,
 
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