okay so i took a trip to mexico and once i got back (a month later) i decided to take the mustang out for a spin, it cranked and idled fine, i went to the post office then went to the gas-station because i realized i had no gas. i pumped up the gas and cranked the car, cranked fine put it in drive and i ran fine. as soon as i got to a stop light the car started idling bad, give it a lil gass and its acting like its wanting to cutt off, like a puuupuuupuuupuuupuu and as soon as it gets a little farther it runs fine, you can floor it and picks up fine, but it idles horrible and assoon as i wanna give it a little gas it wants to cutt off on me, i looked under the hood and took out the fuel filter and blew on it and its not clogged up but when i took the fuel filter off there was no gas in the hose, could that mean my sending unit is bad?
please someone help i was wanting to put it in a car show this weekend to put it up for sale i wanted to buy my daughter a nice DD.

 

No. The fuel pressure of the system is such that it won't necessarily have fuel in the hose. Not like today's cars with their high pressure fuel rails to make the injectors work correctly.

However, I had a similar issue with my '66 I-6, and it wound up being the fuel pump.

BUT... it sounds more like a clogged up carburetor idle circuit, or the floats have sunk. You might need to find a shop that knows carbs, or get to know how to deal with them. Or buy a new one and deal with it that way, although there will still be adjustments you'd have to make to get it right.

Heck, take it to the show, ask about for any help, have the tools you might need (various screwdrivers, needle nose, etc) and see if one of them is a guy who'd help out a fellow Mustanger/Old Car Collector.

Or rebuild the carb, and swap out the fuel pump. That'll guarantee it works right.

Come to think about it... might wanna check your timing, and/or perhaps replace points, condenser, plugs, wires, coil, rotor, and cap. These could also be a potential cause.

Past that... Hm. Again, perhaps a shop is in order.

 

wierd thing is i took it for a spin this morning and it idled fine and drove it for about 8 minutes to autozone and cutt it off and on my way back it stated acting up again. im going to take the carb and rebuild it myself, theres always a first time for everything, but if that doesnt work ima switch out the pump see if thats my issue, but i thought the pump on these cars were mechanically and dont fail, but its also cheap so ill switch it out any way, hopefully ill fix my problem before the show, if not ill just take it and be honest on how its acting maybe they will know the fix. but thank you very much!

 

Oh, no no no... mechanical pumps fail, definitely. The lever inside the block moves the diaphragm in and out, causing a the pumping action that moves the fuel up to the carb. Sorta like a heart chamber. So when the diaphragm loses integrity... there ya go.

Thankfully, the low pressure and way it's made means it doesn't contaminate either way, so it just... doesn't work.

But definitely, YW and good luck!

 

Yeah.
And If it is the fuel pump don't park pointed down a steep hill.
I had a pump go on me and had parked it that way...
Almost all the fuel leaked out of the tank from the fuel pump in the front.