[Eod]

i just went outside to go run a quick errand and i turn on my car, but it won't stay on! it will turn on, telling me there's nothing wrong with my battery or alternater, but it just kills itself. can anyone enlighten me on the subject?

[TheUNZippee!]

Does it run properly otherwise? Like, if you drive it away, is it perfectly fine?

Also, how does it idle? Is it idling smoothly? Is it idling low? And how does it idle/run once it's warmed up?

[Eod]

i tried driving it around, but once i take my foot off the gas it just dies. it doesn't want to idle at all.

[TheUNZippee!]

And how does it run when you drive it, besides the idle problem? Running smoothly, or roughly...is it missing at all?

[Eod]

it'll drive fine until i let go of the gas. i let it "idle" in 1st gear and it stayed on but at extemely low rpms

[TheUNZippee!]

All right. It sounds like your IAC or your TPS. (btw, I'm not sure what year your car is, but I'm fairly sure it has both of these sensors on your engine)

The IAC is your idle air control valve, and sometimes cleaning it will fix this issue. It may also just need adjusting. The TPS is your Throttle Position Sensor, and it can also cause this. Try adjusting or cleaning the IAC first.

I'll see if I can search around on google to find out more for you.

[Eod]

i appreciate the help. i'm gonna go try it out. and my car is a 98' GT (well...at least the one thats not working well) and a 94' GT

[MustangMatt96GT]

iac or tps like zipster said.

[TheUNZippee!]

okay good luck man. My first choice would be to test the iac.

[StangAddiction]

Originally Posted by TheUNZippee! All right. It sounds like your IAC or your TPS. (btw, I'm not sure what year your car is, but I'm fairly sure it has both of these sensors on your engine)

All 4.6 mustangs have an IAC and a TPS...

Actually, I believe all EFI mustangs have both to the best of my knowledge...

[TheUNZippee!]

Hey, EOD. I have some cool help here for ya.

First, go to this thread here in the forum, and follow the instructions for this free manual place: Clicky For Manuals

Once you're there, find your way to your year and model of car.

When you are at your proper manual, look for the 'EMISSIONS CONTROLS' section.

Click that. When that expands, then look for the 'ELECTRONIC ENGINE CONTROLS' section.

Click that. You will see in there all the different electronic sensors for your car, including the IAC & TPS, and how to remove and replace them.

[TheUNZippee!]

Originally Posted by StangAddiction All 4.6 mustangs have an IAC and a TPS... Actually, I believe all EFI mustangs have both to the best of my knowledge...

Thanks for the knowledge SA

[Eod]

thanks. i just took it off and i'm about to start cleaning it. i really appreciate the help. i'll let you know how it goes

[TheUNZippee!]

Wow you work fast. lol Good stuff.

[Eod]

no luck with the iac and i don't have a multimeter so i cant check the TPS.

[StangAddiction]

Originally Posted by TheUNZippee! Thanks for the knowledge SA

Yeah...im trying to process in my head how a efi car would work without a IAC or a TPS...Especially a TPS...

[TheUNZippee!]

Magic, SA? lol

No luck meaning cleaning it didn't work, Eod?

[Eod]

yeah. i cleaned it, but nothing.

[StangAddiction]

Originally Posted by Eod yeah. i cleaned it, but nothing.

Maybe the TPS is faulty, or maybe somthing threw the throttle body outta whack and its completely shut at idle (0 degrees straight)... i believe its supposed to be slightly open at idle... That would definately kill it.

[Eod]

i guess i'll see if my friend will let me take the TPS off his 98.