[nextlife]

Ok, so I just got a 99 Mustang GT manual tranny with 17,000 miles on it (previous owner got a ticket and parked it for a long time) about 3 months ago, and it's giving me a little trouble. When I first start it up the RPM's drop to around 400, it's barley running. Then when I drive it the RPM's drop really really fast so when I shift I need to keep giving it gas while the clutch pedal is pushed. When I have it in 3rd or 4th and don't give it any gas it pulls down really hard since the RPM's drop so much. It used to have this problem every now and then and after driving it for about 5 mins it would go away but now it won't go away at all. I just changed the fuel filter, air filter, engine oil, and transmission oil, so it couldn't be those, and I just put in some Heet so I suppose I'll see if that helps. Just wondering if any of you pro's know what it could be, any feedback is much appreciated, thanks.

[HMUSN]

bad gas.
bad oil.

how long was it sitting?

[nextlife]

year or so, I just changed, Transmission oil, engine oil, Air filter, and fuel filter. I have had it for about 2 months now and no problems until about a month ago when it would do it and then stop, but now it won't stop

[HMUSN]

your Aic could be going out.

[armymike63b]

i would drain all the gas and fluid and do a tune up

[OcOnnor220]

Do you have a check engine light?

[nextlife]

No check engine light. Thanks for all the advice guys

[OcOnnor220]

Maybe its not engine or fuel system related then, a lot of times when Ive ridden my clutch all day it'll bind up and become unbearably stiff...then when I depress the pedal the RPMs will drop to a very low level...and shifting during driving takes more gas pedal too.

[B0B]

my brothers mustang was doing this same thing about a month ago. it was a bad IAC (idle air control) valve. its an extremely easy fix, only 2 8mm bolts hold it on. that definately sounds like your problem. try just unplugging the IAC with the car running and if it makes no difference in your idle whether its plugged in or not then you will know it is bad. you can get a new valve from any local ford dealer for $104. i shopped around and got one for $96, they definately aren't cheap. before you replace it i would try cleaning it with some throttle body cleaner

[nextlife]

Thanks bob17830 I will deff try that test when I get home and let you guys know if it's that or not

[B0B]

sounds good, if you need any help and nobody responds on this thread just shoot me a PM i will try to walk you through it since i've done it recently. good luck bro

[nextlife]

Thanks man, will do