1988 Ranger now quits running with gas cap on

Gassed up this am - had 1/4 of a tank to start. At about 40 miles of driving today it started running rough and then died. Never had a problem with this truck before. Now no start. I think I got some bad gas with water in it (?). I walked to an esso station and bought some gas line antifreeze and some stp fuel cleaner and poured them in the gas tank.

Started right up and ran fine. Problem solved I thought. Drove about 10 miles and engine started rough again and stalled. No restarting it. Had another antifreeze bottle so I dumped it in, engine started. Went a couple of blocks and died.

Got towed home. Driver unhooks my truck and it starts up and runs fine. I leave it running and half an hour later come out to find it stalled.

The only thing I can think of is sediment on the screen in the tank from bad fuel must have got knock off during the tow and that is why I could start it again (?)

Next I tried to run it for half an hour with the gas cap off, came back out of the house and it is running. So I put the cap back on and went in the house, came back out half hour later and truck is stalled.

This time I started it up without removing the cap, it will run for about 45 minutes and then stall.

I thought it might be the fuel pump, now I don't know what gives. Don't know if it is the cap because I haven't ran it for more than 1/2 hour with cap off.

Any help on where to start would be greatly appreciated.

Gary.

Thanks Joe, I will be doing that this weekend. I looked underneath at the frame rail and there is a black cylinder with a semi cover on it on the tank side of the exterior fuel pump, then on the other side of the fuel pump about a foot toward the engine side there is a silver canister. Are these 2 items the fuel filters? Is there any filter I need to change inside the gas tank if indeed I got some bad gas - which I am pretty sure must have happened.

Odd thing though, it started right up this morning and I did a bit over 60 miles of driving today and not even a sputter from it. Go figure(???)

Gary

Thx Joe, it is a 2.9L and seems to be running well now. I have put about a half tank of new gas in it since too.

It doesn't hurt to replace the fuel filter, so it is the silver canister that is the fuel filter along the rail?

Yes. On my BroncoII (with the 2.9L) the fuel filter is on the inside of the driver's side frame rail near where the transmission and t-case are located. This particular model filter has quick and easy snap connections. (my friends' Saab and Volvo have bolts holding the fuel line on the filter; not nearly as much fun to replace) The filter should cost around $7 or so.

-D

Thx Derrick,

thx for the Lewis quote, I'll take that through my day tomorrow, esp as I crawl under the truck and do some wrenching. ;-)