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MG TD TF 1500 - Blocked fuel line

I now have a TD which has not been used for nearly a year. In trying to get it running I have discovered that the fuel line is partially blocked with, I think, old petrol which may have evaporated in the hot weather we have been having recently, leaving some sort of plug.

I have drained the tank of some suspiciously looking old petrol and have been able to make a partial clearance by blowing compressed air backwards through the pipe from the pump end into the tank and also by applying suction at the same end via my mouth. A small amount of fuel is getting through but insufficient to allow the motor to run.

Does anyone have any tips as to how to clear the pipe completely or am I left with no alternative but to replace it?
G.E. Love

Is the fuel line still on the vehicle? If so, this fix may work on or off the car. Measure the internal diameter of the fuel line. Go to the hardware store and pick up a 25 foot electricians fish tape that is not too wide. You can get them for about $10 to $15. It may or may not have a blunted end that may or may not fit through the fuel line, but it should be a thin strip of steel about 1/8 inch wide, which with the end removed will fit through the fuel line.

Run the snake through the fuel line, working it back and forth, clenaing the line, and then flush with brake cleaner and compressed air until you get a good flow. Repeat as needed.

warmly,
dave
Dave Braun

Thanks, Dave. I'll try that now and report back.
G.E. Love

You should probably check with Dave D. on this to make sure it won't damage the fuel pump. Try running a gallon of cheap laquer thinner through the system a few times. It will clean out the old crud but I'm not sure what it would do to the pump. Be carefull blowing compressed air through the lines. The friction of the moving air and the particles can ignite the fumes.

LaVerne
LaVerne

Laquer Thinner is probably good but so is acetone. Put it in the pipe and let it soak overnight then blow it out.

Are you sure it is only the pipe, or could it be varnish on the strainer screen that is on the tank outlet fitting?

Cheers,

Bob
bobj50

Be sure to also check the screen at the fuel pump itself. This, along with the screen in the tank may be part of the issue.

Jeff
J Delk

LaVerne, I would be shocked if the combination of brake cleaner and compressed air, with or without friction from particles caused a fire. And even if it did, it would move in the direction of the airflow, or out the other end of the pipe. At any rate, the compressed air will clear out the brake cleaner, I doubt much of a residue would be left. I do appreciate your bringing up these points as I think home-made remedies such as I suggested have the potential for disaster, and second opinions are welcome... especially from those as knowledgeable and thorough as yourself!

Also, and a big assumption on my part, is that both ends of the fuel line are disconnected prior to running the fish and spraying with brake cleaner.

Bob, I didn't consider pouring acetone into the pipe and letting it sit, but it isn't a bad idea; if the fuel line is in place you could attach a rubber hose with a clamp to the fuel tank end leaving the end of the rubber hose higher than the pump end, disconnect the fuel pump end, pour the acetone in the rubber hose until it appeared at the fuel pump end, and cap it off. I do like the idea of the snake for a tough clog though. It would probably dislodge quite a bit, and we know that the fuel pump is capable of passing safely large chunks of debris to the internal filter.

warmly,
dave
Dave Braun

Dave, I was suggesting Laquer thinner as the solvent because I know it will cut through the crud, is easily available and relatively inexpensive. I gave the warning about the compressed air because the thinner is extremly flamable and I'm not sure what fuel might be here or there or what the line might be connected to. I have seen myself ( don't ask )compressed air pushed through a fuel line cause flames to shoot out the far end of a fuel line. Lucky I er he didn't set the house on fire.

LaVerne
LaVerne

Everyone else has covered this subject pretty well. I will only add that, as Bob Jeffers and J. Delk mentioned there is a filter both in the tank and in the pump (both are removable) these should be take out and cleaned thoroughly cleaned. It is imperative that the inlet side of the pump (from the tank clear through the filter screen in the pump) be free from any obstructions. Any clogging on the inlet side of the pump will cause the pump to fail in a current on condition and if the power is left on while this condition exists, the pump will be damaged. Cheers - Dave
David DuBois

Laquer thinner is great, but so is acetone .. also known as nail polish remover.

I've ued this solution for years - never fails. But do it outside in an open area.

Gord Clark
Rockburn, Qué.
Gordon A. Clark

G.E.
Another thing it might be is: that the new gasoline with the high ethanol content has loosened up the sloshing/ gas tank sealer material in the gas tank, if aviation grade slosh/sealer was not used. I think I would loosen the fuel line at the tank filter and see what comes out. The drain plug is located next to the filter and gas line connection. If a substance like caramel comes out of the line then the gas tank slosh/sealer has loosen up and is in the bottom of the tank. I have first hand knowledge of this event. Good luck, John
John

Aviation grade slosh/sealer, at least the one I got about 25 years ago is not ethanol proof. I had just that situation of the stuff dissolving and the gluing the needle valves in the carbs and the check valves in the fuel pump shut. I wound up having the tank dip stripped and given a phosphate treatment rather than using sloshing compound again (also had to have the tank repainted). Cheers - Dave
David DuBois

Well, thanks for all your valuable comments. Here is a synopsis of the procedures utilised and results.

First, following Dave's suggestion, I shot up to my local hardware store and got a length of electrician's fishing tape. Owing to its rigidity, it would not conform to the pipe's convolutions and quickly became jammed. Had the pipe been out of the car and reasonably straight, that would have worked.

Next, I tried a length of 18 ga. insulated car electrical wire, but that proved insufficiently rigid to be pushed very far along the pipe.

The next try was with 20 ga. steel wire, the sort used for locking wire on nuts and bolts. Because of its stiffness and yet flexibility, that seemd to go a long way along the pipe but in itself, did little to improve matters owing to its narrow width.

Upon withdrawing the wire, I bent the end over, about 3/16" and stuffed it in again. Again it seemd to go about the whole length and upon feeling extra resistance, I calculated it probably had arrived at the tank's filter. I withdrew the wire and tried the compressed air bit. Suddenly the gas tank emmitted a loud and deep booming sound, such as is made in sound studios to simulate thunder. It occured to me that it would be a good idea to loosen the tank's filler cap. Despite this, the pipe still seemd to be obstructed, this being evident by the fact that when the compressed air nozzle was suddenly removed from the plastic tubing I had attached to the pipe at the engine end, I was greeted by a huge rush of air being expelled from the plastic tubing, a fascinating condension of vapour in the tube itself and a hell of a strong pong of petrol.

The end was again bent over upon itself, and the whole procedure repeated, probably 10 12 times, the end being increased in diameter each time.

Eventually, the pipe allowed petrol to be drawn up by my lumgs in such a volume as to give me an unexpected and unpleasant mouthful.

Seems as if that has done the trick, but the next step is to investigate the tank and find out if the sloshing stuff has been dissolved and is the cause the trouble.

Thanks for all your comments.
G.E. Love

I must be missing something here,,,,, with all of the remrdies posted, some will work some will not,,, and the actual results might be questionable as to weather or not all of the blockage is removed,,,,if not all removed, will some of the remaining blockage reapear when you are far from home??? Why not just buy some copper pipe at the local hardware store and replace the whole fuel line to be sure ???

SPW
Steve Wincze

Congratulations G.E! Sorry the fish idea didn't work, and glad you found a wire strong and flexible enough to do the job.

Steve, I think you are missing something here. For some of us, half the fun of the cars is to come up with inventive fixes to problems we can solve at home. Some of the inventions work, and some don't, but the goal is to keep as many original parts on the car as is possible. For example, I could have bought new rear springs, but it was much more satisfying to rebuild the old springs. Does it guarantee the ride height will be correct? Not until I drive it, after all, I didn't try to re-arch them… but I may if I’m not happy with the results. More work, but more satisfying in the long run for me.

When our cars were built, copper lines for the fuel were considered good enough. Now days, it would be prudent to put in stainless steel, but being harder, SS is harder to seal. Our cars have had copper for many years with few ill effects. If the only problem is a clogged line, unclogging it is a reasonable endeavor to keep the original part on the car.

Finally, simply buying new copper line and installing it may be harder than cleaning the line in place, and he still has to ascertain if the blockage exists in his tank somewhere, or the new copper line could become plugged as well. In a nut shell, for some of us, the ‘rebuild or repair’ approach is what we prefer, not better, just different than replacing items.

warmly,
dave
Dave Braun

I cleaned mine with a 1/8" braided steel cable, 11' long.
Len Fanelli

I poured every cleaner know to mankind into the fuel line (with the tank end blocked), and let it sit for a day or two... then I hooked up an airline to the pump end and and let it go for a minute or two....(with a rag wrapped over the end...) Got great black gobs of stuff out of it and it has been fine ever since!!!!
gblawson(gordon)

I didn't read all the posts, but here's what I did:

I took out the speedometer cable and used that for a snake. Then fuel and air (no sparks at the end) while blowing! Got it far enough that with a filter, it'll be ok.
Tom

Tom - "Got it far enough that with a filter, it'll be ok."

Thats' not a good idea. A modern day, high efficiency filter in the inlet line to the pump can become clogged very quickly stalling the pump in a current on condition, causing damage to the pump. See the article, SU Fuel Pumps Facts and Myths in the SU Fuel Pump section of my web site at: http://homepages.donobi.net/sufuelpumps/ It is much better to get the line absolutely clean and forgo the extra filter. Cheers - Dave
David DuBois

This thread was discussed between 08/08/2008 and 10/08/2008

MG TD TF 1500 index

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