72 Ranchero GT sputters & pops when in gear

I just got my dads old 1972 Ford Ranchero GT, it has a 351c 2 barrel with a FMX trans, it has been sitting for the last 4 years & only started every couple months but not driven. We replaced the plugs, cap & rotor, fuel pump & accelerator pump diaphram. I runs at idle really well but when put in gear it is bogging down, surging, sputtering & popping. I thought it may have been bad fuel but I put 10 gal of premium in with some fuel system treatment. The other day i took it around the block to see if anything we did helped & it started over heating also. Looking for any advice or thoughts on what could be the issue.

May need to have the carb cleaned/rebuilt. It sounds like you are too lean(whether it's from mis-adjustment or debris build-up) which will cause both of your symptoms. As Madmaxtorino recommended, change the fuel filter and have a look at the T-stat first, if those "fixes" don't help your situation, try backing out the idle mixture screws about 1/2 turn each and see if that helps. If it is a Motorcraft 2 barrel, these are fairly easy to clean/rebuild. Good luck and keep us posted. Todd

Thanks, I will work on that today. Appreciate the help. Keep you posted.

First, did you add the 10 gallons of premium on top of the 4 year old gas in the tank? The ethanol in modern gas goes stale, and absorbs water from the air. This may make a layer of water in the bottom of your fuel yank if the ethanol absorbs enough to go out of suspension in the gas. This happens a lot with boats, they call it "Water Bottom". It also may make little blobs of what looks like clear jelly/jello. these will clog fuel filters and foul carbs. Putting fuel treatment products in will not help much, and will only circulate thru fuel lines and carb as it is used/burned..

Unfortunately I did add it to the old gas because there wasn't very much, so I'm guessing that this is one of the major problems. Does this mean I have to drain all the fuel & pull the tank?

Edited by 72RancheroGT351C - 21-May-2015 at 1:03PM

I've been dealing with a similar issue with my '73 Ranchero. Drained the bad 3 yr old TREATED fuel out of the tank, put fresh gas back in, got the car to run somewhat normal for 5-10 minutes, then it would stumble & die & would not start, unless it sat awhile.  I figured there's a goo ball in the tank. I recently had to transport the car, & to get it up on the trailer, I ran it great off a gas can with 3 gallons of premium ethanol free fuel (didn't know there was such a thing this day & age ) & she ran great. I almost reconcidered trailering & driving it instead, but a brake line opened up so had to trailer it anyway. So my suggestion is to try running it off a SECURED auxillary source,& see how she runs & drives.

HAD THE PROBLEM ON MY 77 COBRA II.  You're going to have to pull the tank and clean it out.

Shhhhh!!!! Ix-nay on the onkey-may!!

Yes, you are going to need a new or cleaned and treated fuel tank.

Clean is the word when you rebuild a carb. Make sure to blow high pressure air though every orifice. Not to hard to rebuild a carb though. You tube is a wonderful thing.

After pics:

Does anyone know if a 64 65 66 67 68 Mustang Gas / Fuel Sending Unit NEW fit the 72 ranchero gt tank? It looks identical

PURE GENIUS!!!!

X3 or 4 on the cement mixer idea! You have some options with the tank, here are a few: A) Have it coated internally, like using POR15 (as Regul8r mentioned) or you can call your local radiator shop and see if they provide this type of service(my father did this for his '57 Olds fuel tank), the rad shop had a commercial type of sealer that was guaranteed not to deteriorate. B) If the tank is more rusted or deteriorated than to your liking you could install a brand new '74-'79 tank(a LOT easier to find), but this requires a new sending unit(you may need one anyway from your replies), possibly longer/shorter tank straps since '74-'79 models came with 22 or 26 gallon tanks and a fuel tank vent that would install where your sending unit previously was positioned(the vent is a $1 at a local wrecking yard). C) Leave it as is = reoccurring troubles and not a good idea. Again just a few things that come to mind.

maybe a long shot, but how are the plugs? a faulty condenser can act like fuel problems! weak coil?