my 96 gt wont idle.

[jmotank]

Ok so I haven't really had a chance to look into it because I worked all day yesturday and today but... I haven't driven the car in a week since its been raining all week. Its just been sitting in the garage but ran fine the last time I drove it last sunday. Well I got home from work last night and the weather was nice. So, I decided to get it out since I was taking my kids out to din and a movie. So I go to start it, it starts right up as usual(only had this car for just over a month)but once it starts it falls flat and dies. Will not idle. I can start it and rev just fine but as soon as I let off the gas it dies. So we had to jump in the wifes suv to head out to the movie. Haven't had a chance to mess with it and I'm working all day today. I hope to get a chance tonight. If not I won't get to until wed(when I finally get a day off) due to my schedule. Just wanted to get your thoughts on how its acting. So, any thoughts as to what it might be?
-sorry for the long winded post, slow day at work so I'm a bit bored lol. Just wanted to see what the folks here might think.

 

[jmotank]

bump for any thoughts. posting from my crackberry at work.

 

[4valvemach]

Dirty or clogged IAC (idle air control valve)

:shrug:

Ive had a TPS (throttle position sensor ) go bad but it made it have a high idle.My 90 gt had a clogged IAC and it would idle very low and almost stall out,I cleaned the IAC and it ran perfect.

 

[02silverstang]

Dirty or clogged IAC (idle air control valve)

:shrug:

Ive had a TPS (throttle position sensor ) go bad but it made it have a high idle.My 90 gt had a clogged IAC and it would idle very low and almost stall out,I cleaned the IAC and it ran perfect.

plus 1 could also be youre maf , youre egr valve , are you getting any codes ? if so that should pretty much narrow it down ..

 

[jmotank]

no codes at all. revs fine but when i let off the gas it doesn't even stumble it just flat out dies.

 

[jmotank]

Ttt

 

[ponygt65]

+1 on double checking the IAC valve and MAF sensor.

Do you know the history of this car? Could need a tune pending history and the dashpot settings are all screwy if it had a tune and FI previously.

Honestly, it could be a few things. Does it 'lag' when you rev it?

 

[jmotank]

No lag what so ever and the car is bone stock. From what I can tell after going over the car it has never been modded. Just odd that last I drove it it was fine. Jump in a week later and doesn't wanna idle.

 

[LS1PUSSOUT]

check all the hoses coming off the intake

 

[jmotank]

i should get a chance to check everything this afternoon hopefully. just odd to me. i will check the intake out too.

 

[jmotank]

Update, I tried starting it yesturday with the same result. But I also noticed the smell of gas. Not from exhaust, but under the hood. Can someone post a pic of where the iac is? I'm not exactly a mechanic lol. I really need to get a haynes manual for this car. Got one for my focus when I got it and have done tons of work using it. Like a mechanics for dummies guilde lol. Any help would b greatly appreciated. I'm just not too savy when it comes to trouble shooting like this.

 

[LS1PUSSOUT]

iac valve is right on the front of the upper intake manifold. The part with the horse on it. The valve has a breather tube coming off it that is attatched to a little black plastic box and goes on to the intake.

 

[ponygt65]

Picture:

http://www.moddedmustangs.com/wp-content/uploads/2006/07/iac-valve-4-6.jpg

 

[jmotank]

ugh, what a pain in the ars. it doesn't seem to be the iac.

 

[1996stang]

My expedition just done a very similar deal.It had a vac leak that would not let it idle at all and the smell of gas was very strong. Turned out the line's from the pcv to the back of the intake had a bad crack in one of them.It is a 5.4 so im sure there is some difference between it and the 4.6 but it might be a starting point.

 

[jmotank]

so damn frustrating. i still can't figure out wtf is going on here. ugh!!!

 

[jmotank]

:shrug: :fm::cuss::mj: then it turns to this:cryying: because i'm a:loser::smmon: andcan't figure this out. i'm so:??: i'm just gonna:burn:myself. LMAO ugh

 

[LS1PUSSOUT]

bad intake gasket? MAF to filter gasket?

 

[ponygt65]

Did you ever check your TPS voltage and the IAC valve?

as for the fuel smell...most likely from you trying to start it so much.

 

[OldSkoolStang]

Did you ever check your TPS voltage and the IAC valve?

as for the fuel smell...most likely from you trying to start it so much.

^^^What he said. I have a '98 GT and have had the exact same issue twice.
Once: The IAC valve electrical plug was not making contact. I gobbed it up with dielectric grease and plugged it back up. That fixed the problem for me.

2nd time: The hose leading from the IAC to the cold air intake came off and it would not idle at all, it just shut off if you weren't in the gas.

Check those two throughly. If you can't find anyting get someone to keep the car running, get a can of brake parts/car cleaner and spray around all vaccuum lines/fittings. If it ever revs up you've found a leak......

Hope this helps....