davoaz

comes the dumb question.


72' 350 4MC carb.


So I'm driving along and it went kaput.


I've narrowed it down to fuel problem.


I disconnected fuel line after pump and it's pumping. I can put a shot of gas in the carb and it fires up until gas is gone.


So here it comes, is the fuel filter the round ~ 1.5" dia cylinder that screws into the front of the carb?

1970cs

It should be! Fuel line leading in from the pump.

Pat

tru-blue 442

Yes. When replacing it, be careful
not to over tighten it, or it can
strip the threads. I use a 1" and a 5/8"
wrench to break it loose, and also to re-tighten.

davoaz

Thanks.

I thought it was. Looks like that thing is corroded on nice and good.

Is the filter a common insert part that still can be found at NAPA or should I start browsing a classic parts vendor?

tru-blue 442

You should be able to find one at any parts store.

jaunty75

$2.99 off the rack at AutoZone.

http://www.autozone.com/autozone/par...er=830800_0_0_

davoaz

Holy cow that filter is small. Do I need to take the entire hosing off or does it slide in from front?

Professur

Heads up. The seal is a thin transparent ring that will probably stay on the end of the nipple. I bought a bunch of filters and none came with a new seal. Ask for a new one.

Also, the housing ... use a stubby wrench if you have one. With a new seal ring, that's more than enough.

jaunty75

How big does it have to be?

It should be right there where the fuel line from the fuel pump attaches to the front of the carburetor. You'll have to remove the air cleaner to get at it. Loosen and remove the fitting, and the filter pops right out. It couldn't be easier. Just make sure that, when you install the new one, it's oriented properly (the car wouldn't run if you put it in the wrong way, anyway, so you'd know in a minute if you made a mistake) with the open end away from the carb. Be sure the tension spring is installed as well. The new filter might come with one, but it might not.

Below is a photo of the 455 in my '73 wagon, and I've circled where the fuel filter is located.

davoaz

Heads up. The seal is a thin transparent ring that will probably stay on the end of the nipple.
So what's up with the rubber insert with spring and plunger. Seems like that would impede the hamper flow of gas into carb. Picture of it in CSM doesn't even show it.

jaunty75

I got a new pump-to-carb line for my '67 Delta 88 from inline tube.

http://www.inlinetube.com/

Fun71

That type of filter came into play way after our cars were built so it wouldn't show up in the CSM. There is a version of that filter without the check valve - I used to sell a lot of the non-check valve filters when I worked at auto parts stores in high school/college as many folks didn't like them. The check valve is supposed to help prevent fuel from siphoning out of the carb and flowing back into the lines. The spring is weak enough for the fuel pump to overcome it so it's not supposed to interfere with fuel delivery.

Sugar Bear

Good diagnosis. Use a lot of caution changing that filter, it is easy to strip the fine threads in the carburetor. If you are not totally comfortable changing it try to find someone with experience to do it or guide you. Good luck!

davoaz

I got it going and will soon have a replacement fuel line on the way. I have a feeling I will be into this again. I tested pump a 2nd time last night. Pumped gas in to a clean jar and noticed grit in the bottom of the jar. This is the 2nd tank since I owned it. Either its been in there and caught up with me, or the ethanol they put in gas is getting old sludge to come loose. May be time to plan on a new gas tank. I'll never get to my dual exhaust or Headers at this rate.

Fun71

You could put an inline fuel filter before the fuel pump to strain that grit out before it gets to the pump and carb.

jaunty75

Putting a fuel filter before the fuel pump is just treating the symptom and not the problem. Your car was designed to work with two filters in the fuel line, the fuel filter just before the carb and the sock filter at the end of the pickup tube in the tank itself.

If you're getting crud into the fuel line to the extent that you're contemplating adding yet a third filter into the line, the thing to do is to fix the problem properly, which means dropping the tank, having it cleaned or cleaning it yourself, putting in a new sending unit or at least a new sock filter as I'm guessing the one in there now has failed in some way (either full of holes or fallen off altogether), and then putting things back together and enjoying your new, clean fuel system.

davoaz

dropping the tank, having it cleaned or cleaning it yourself,

If I do drop tank and "clean myself" what is the process to do this? I think it probably involves more than draining, hosing out with soap water and drying.

jaunty75

Actually, soap and water is exactly what it means, and that's exactly what I did. Obviously, when you take down the tank, you'll remove the fuel pickup/sending unit and look inside, what you see will tell you what to do.

Back in 2010, I dropped the tank on my '67 Delta 88 to put in a new sending unit, and when I first looked inside the tank, it was very shiny, which was good, because it meant there were no deposits of any gunk or anything. But there was loose crud on the bottom, which I'm sure is inevitable after 40+ years (probably after far fewer years), but this is expected by the designers of the fuel system, and that's why the pickup pipe comes down from the top of the tank instead of drawing the fuel from the bottom the way a bathtub drains. I'm sure you'll find a lot of crud because it seems to be getting into your fuel lines.

So I let the tank dry of gasoline thoroughly. I think I let it sit out in the driveway with the sending unit removed and no cap on the filler neck for two days. Then I squirted a little degreasing dish detergent into the tank and took a garden hose with a nozzle and sprayed water all over the inside, through the sending unit opening and through the filler neck. I'd put a few gallons of water in the tank doing this, then swish it around, and then pour it out, sometimes through the sending unit opening and sometimes through the filler neck. Each time a bit of the crud came out, but you'll never get all of it this way.

Once I had done this maybe a half dozen times (I put dish detergent in only the first time), while the tank was still went inside, I went in through the sending unit with a few dry paper towels in my hand and scooped and swept up as much of the crud and dust as I could reach. After two or three times doing this, I gave the tank one more thorough rinsing and then left it in the driveway again for a couple of days to dry out. Then I took my shop-vac and vacuumed out the inside of the tank as best I could for one last go at getting as much crud out as I could. With the flexible hose, I could get it all around the inside of the tank. And that was it. I put the new sending unit in, put the tank back on the car, and off we go.

If you find something other than a shiny inside, then you probably have some "varnish" deposits or whatever, and taking it to a radiator shop to have it "boiled" or whatever they do to them to get this sort of thing out would be in order.

Allan R

If you drop the tank? Just my opinion, but take it to a rad shop and have it cleaned professionally. No hassle, no fumes etc to deal with - they're set up for this. Plus they can test it for leaks. Your choice on how you want to clean this out, but my money would be on the pros. They'll likely do a better job too. If you're getting crud in the carb line, you likely need a new sock for your sender. Either that or just replace the sender at the same time.

Professur

I'll just throw in .... have them drop it. Without fail, you're going to be facing rusty bolts and straps and this is one place where the blue tip wrench is no help at all. Then you're trying to catch a usually greasy tub full of flammable liquid which will slosh about at exactly the worst time. This is one of those jobs that you could do if you had to ... but it's just sooooo worth the price to avoid. $75/h? Please take my money.

Allan R

Good thoughts. I dropped mine myself because it was empty and the bolts weren't as bad as most. I agree if the shop can do it for you, much less hassle.

jaunty75

The bolts were rusty on my '67 Delta, and I had no trouble hacksawing the ends off and knocking the straps off the ends of the bolts with a few taps of a hammer. The straps themselves were fine. I got new bolts at Lowe's.