Gas tank debris?

DANIEL W.

MEMBER
1971 FORD MAVERICK
125,000 MILES

I hadn't run the Maverick for almost two years. After changing the oil and putting in a new fuel filter (screws into the carb), I started it, and in a few moments gas was shooting out the fuel filter where the hose connects to it. I suspected that it instantly clogged up with rust/dirt particles. Replacing the filter, it ran fine. Then after a few days of driving it, the car started to idle roughly and stalled at stops. I thought the problem might have been the fuel pump (which I hadn't replaced in years). That seemed to help a little, but the problem soon returned. I rebuilt the Carter YF carb, finding very few particles, but I did find a bad pump diaphragm assembly. Fearing that there may be rust or dirt that could enter the carb--since I can't afford to pull out the tank for a complete cleaning--the only alternative I can think of is to supplement the carb fuel filter with an in-line (plastic see-through) filter connected bewteen the tube that comes from the gas tank and the fuel pump (mechanical). One professional mechanic said that this was a good idea, another told me that the two filters would hinder the flow of gas to the carb. Who's right or is there something else I can do that won't cost too much? Thank you for your help!

Tuesday, June 12th, 2012 AT 5:57 PM

4 Replies

CARADIODOC

MECHANIC
34,331 POSTS

There's already a screen on the pickup tube in the tank. Those can become plugged or they can collapse and block fuel flow, typically after driving about 10 - 15 miles, then they'll stretch back out after letting the car sit a few minutes and will work again for a few more miles.

In the past people have removed the gas cap, then removed the inlet pipe to the fuel pump and used compressed air to blow that sock off the pickup rather than taking the assembly out of the tank to do it. Then they installed an inline Chrysler filter. Those filters will last the life of the car.

Even if you leave that sock in place and it isn't plugged, adding a Chrysler filter will actually mean you have three filters. It's the fuel pump's job to pull a vacuum and draw fuel through all of that. The Chrysler filter is so low in restriction the pump won't even know you added it.

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Tuesday, June 12th, 2012 AT 6:46 PM

CJ MEDEVAC

MECHANIC
11,004 POSTS

JUST A THOUGHT

ARE YOU SURE THE FUEL WAS COMING OUT "JUST" AT THE INLET?

COULD IT BE THAT THE "FLOATS" WERE STUCK IN THE DOWN POSITION, THE NEEDLE AND SEAT COULD NOT CLOSE, AND THE BOWL OVERFLOWED?

THE MEDIC

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Wednesday, June 13th, 2012 AT 12:57 AM

DANIEL W.

MEMBER
2 POSTS

Hello, Caradiodoc and CJ MEDEVAC,
Thank you for your suggestions and advice. After attaching an in-line clear fuel filter and seeing the gas in it, I can surmise that if there were any loose particles in the past, they're gone now. I don't believe the carb float was stuck when gas spit out since after the initial incident, I replaced the screw-in filter and there were no further problems.

Here's the latest developments on the car: After replacing all but one vacuum hose (the exception being the "L" shaped one that connects from the transmission to the carb via a metal tube), I started the car and it still idled roughly. Inspecting the standard distributor points, I saw extreme wear so I replaced that and the condensor. The rotor and cap looked good as did the spark plugs when I initially checked over the engine after not having driven it for two years. The idle is less rough, but still noticeable, and a bit rougher in gear. I noticed a little moisture around a top carb screw. So I re-tightened them all, but that didn't seem to help very much. I will admit that some of the screws aren't as secure as others, but I feel that overall it's tight. The idling seemed to smooth out a little when I placed my hand over the one barrel opening, and when I pressed the pedal a little the roughness abated slightly also. I'm running out of things to adjust and replace. The only things I've not changed are the vacuum advance and distributor. This car has no power steering, a.C, or brakes. I don't expect it to run like new, but I have had it running smoother in the past. Any thoughts?

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Friday, June 15th, 2012 AT 2:39 AM

CJ MEDEVAC

MECHANIC
11,004 POSTS

CLOSING OFF AIR TO THE CARB, AND BETTER RUNNING, COULD BE A VACUUM LEAK. THIS IS NOT JUST LIMITED TO HOSES, YOUR CARB MAY BE LOOSE ON THE MANIFOLD, THE INTAKE MANIFOLD MAY BE LOOSE ON THE HEAD, YOU COULD HAVE A VACUUM PORT ON THE CARB OR INTAKE THAT MAY NEED TO BE CAPPED.

YOU MUST HAVE A SIX CYLINDER, NECESSARY VACUUM LINES ARE "PCV"---"DISTRIBUTOR VACUUM ADVANCE"----"TRANNY"

DO YOU KNOW HOW TO TUNE YOUR CARB?

WHAT IS YOUR IDLE SPEED?

CHECK TIMING?

CHECK YOUR ADVANCES WITH A TIMING LIGHT?

DO YOU HAVE A DWELL/TACH METER AND A "PLAIN JANE" TIMING LIGHT?

WE MAY BE ABLE TO HELP YOU WITH SOME OF THIS, I HAVE MY 6TH JEEP CJ 5 AND ALSO A '46 WILLYS. MY CJ 5 ORIGINALLY HAD A CARTER YF. OVER THE YEARS, I ADDED A 2 BBL, AND PRESENTLY HAVE A HOLLEY 4 BBL.

I HAVE A QUITE A FEW PICS ON HERE DEMONSTRATING TUNE-UP AND OTHER STUFF

YOU CAN ALSO SEND US PICS OF YOUR ENGINE, ETC. REMOVE YOUR AIR CLEANER SO WE CAN SEE!

THE MEDIC

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