Well after replacing everything from the fuel pump forward on my 72 F100 (that I purchased after it had been sitting 5 years) , I'm still getting a fuel starvation issue, so I think the in cab tank's fuel pickup is clogged.

Dennis Carpenter lists D0TZ-9002-A as the tank for 61-70 models, and D1TZ-9002-A as the tank for 71-72, with the only difference appearing to be evap provisions on the latter tank.

The prior owners removed the evap canister and the evap lines were just left open down by the frame rail, so I see no reason to go back with the evap tank. So my question is, what other parts do I need to order? I think the filler neck grommet diameter is different for non evap tanks, correct? And I'll need the vented fuel cap? Am I missing anything else?

 

Your 72 will have the 3/8 inch fuel line rather than the earlier 5/16 inch fuel line. You should stay with the original setup. By the way, in 35 plus years as a professional mechanic I've not ever seen a clogged fuel tank pickup tube. You need to pull the sending unit out and look inside the tank rather than just order a bunch of parts that won't fix your problem. Either prove or disprove your working theory. Also remove the fuel line from the tank where it connects to the top of the tank and inspect it, you should be able to run a small wire down it to confirm that it's not clogged. I'd spend the money for a small inspection mirror and stick it down the sending unit hole to take a look at the bottom end of the intake pipe.

 

Ok I'll give that a shot first. Do you know if there is some type of "sock" installed on the end of the pickup tube? If I fish a wire down the pickup tube from the top I assume it's a straight shot down to the bottom of the pickup?

 

Can you blow air into the tank line from the fuel pump?

 

No, there's no sock on the pickup tube on a 67 -72. the pickup tube is made as part of the tank. Yes it is a slightly angled shot down to the bottom of the tank.

 

Ok thanks I'll give the compressed air or wire option a shot this evening before ordering a tank.

 

More likely what has happened is that the permanent suction tube has pinhole from rust in it. I had fuel starvation issues from the main tank as well. An electric fuel pump helped the matter but of course did not solve it. Keeping the tank full also helped as there was less suction tube exposed in the tank.

I just now replaced the tank (although I'm going to keep the elec fuel pump!).

Verifying if the intake tube has pinholes in it would be difficult and time consuming. For the modest price of around $200 you can just simply get a brand new tank. The other problem I was having with mine was sediment getting sucked through the system - small bits but it would get into the carb and foul the idle circuits. I had the tank cleaned about 10 years ago at a reputable shop. I'm really not sure it helped - it seems when tanks get old it is just easier to get a new one. And of course there is no way to fix the suction line even if you were able to verify it was rusted out.

While you are at it, replacing or at least verifying the fuel line from tank to pump and pump to carb are good (and new replacements are available provided it is not a Camper Special).

 

As usual, Carpenter doesn't have a clue! Where the hell he got these applications from, I dunno.

This 1970/72 D0TZ tank was also the FoMoCo "service parts replacement" for the original 1961/69 tank.

D0TZ-9002-A (replaced C1TZ-9002-K) .. 19 1/2 Gallon In-Cab Fuel Tank / Reproduced by Blue Oval Truck Parts (Anaheim CA) that sells it to the repro parts sellers and the general public.

1961/66 F100/800 / 1967/72 F100/750 except 1970/72 F100's with Evaporative Emission (Evap/Em). 1970 F100 Evap/Em tank (D0TZ-9002-C) is different than 1971/72.

Evap/Em was introduced in 1970, was mandatory in sold new in CA F100's, Passenger Cars, Bronco's and E100's.

But since not all states mandated it, 1970/72 F100's might have it, might not.

 

Hey ND,
My.72 had evap, but assuming I go with the service replacement tank (which is non evap), what fuel neck grommet should I go with (where the filler neck passes through the cab)? DC lists two different ones, with one for 67-70 and one being specific to the 71-72. Confusing!

 

What's confusing is DC's BS applications!

D0TZ-9080-B .. Fuel Tank Filler Neck Grommet - Use with In-Cab Fuel Tank / 3.45" O.D. x 1.91" I.D. x .91" thick.

1970/72 F100/750.

There's another for 1967/69 F100/750 in cab tank (C7TZ-9080-A), but if replaced by the D0TZ tank, you could use the 1970/72 version. The only 1967/69 difference is its 3.29" O.D.

Plus, there are two others for the Styleside 1967/69 F100/250 & 1970/72 F100/250 auxiliary fuel tanks (C7TZ-9080-B & D0TZ-9080-A)...and that's it for 1967/72.

 

I had lots of problems with my fuel tank too. Someone used radiator hose on the filler neck, it had deteriorated and I had rubber goop inside the tank. I replaced my original tank (my truck is a 69) with a evap style tank from a 72. Some things were different- the filler neck, and the way the tank physically mounts up took some creative solutions to fit. I cleaned it several times and coated the inside with 2-cycle oil. I capped off all the evap stuff and modified my non-evap filler neck to fit (the gas caps are different, vented vs non-vented).
Still had fuel delivery problems. Switched to an electric pump with a relay to power it on. Still had fuel delivery problems. I think it was the vented cap not actually venting, adding a fuel injection one-way vacuum) valve on one of the evap outlets so it could pull in some air finally sorted it.