My 20001 Mustang Conv has sat in the garage now for a year and a half and won't run. It'll start, but won't run. Help! Yeah, I'm a girl.

Best to use a OBD2 code scanner and check for any stored codes.

hi,im elroy, u should change the oil and oil filter,drain old oil and refill with new oil, dont forget to change the oil filter before you refill with new oil.change all spark plugs

Your problem is it is a ford,LOL:

The fuel system is most likely gummed up from bad gasoline, flush the entire system, replace the fuel pump and the filter as well. Add a can of CHEMTOOL to the gas tank to help dissolve the varnish.

The first thing I would check is fuel pressure. This type of fuel injection requires a minimum fuel pressure in order to operate. If fuel pressure is as little as one psi below minimum the vehicle will not start. You can try squirting a couple of shots of carb spray into the air snorkel while somebody cranks the engine over. If the engine starts and then dies you now you fpdeffinetely have a fuel issue. If the engine still won't start check for spark. Let me know what you find. Let me know if you have any questions and I'll do my best to answer them. Thank you for using FixYa.com!

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

yeah, try starter fluid just to verify if it;s fuel or spark related. If it starts or tries to, then it's a fuel problem. You should be able to hear your pump turn on, when you turn key on, may need to stand by tank, when someone turns key on. it should activate for about 2 seconds, with key on.(that's to pressurize your system with gas) then when cranking, the pump should run(may not hear it then-so just listen when key is initially turned on. No noise: your pump may not be working. If you can hear the pump, it may be another issue.

Try adjusting the air-feul mixture or just turn the idle up a little bit. For either of these there would be a screw adjustment near carb

tighten the valve cover gaskets... if that doesn't stop the leak replace them.

Clean the throttle body with c.r.c. get it at autozone ect.The t.p.s. (throttle position sensor) could be acting up.The t.p.s. controls how much air/fuel enters the throttle body and if your problem only happens in the summer this may be your problem.