5.0 Wont idle after warm?

I'd check temp and oil sending units
Just had a similar problem on cousins saturn. Wouldn't start when car was hot unless
you flat footed the gas.
Changed the temp sensor, and connector, problem solved
Amazing what incorrect readings will tell your fuel system to do...

Where are you located? I have a similar problem. My car starts and idles fine when cold but after warmed up I have to hit the gas to keep it running. I have swapped throttle bodys, IAC's, tried the plate between the IAC and the throrrle body. Got some oil in the intake though no idea why.

More Details

I bought the car wrecked and put it back together so I dont know a lot of history on the car and I didnt drive it very far before I bought it because it was wrecked. I think it has a bigger than stock fuel pump in it because I can hear it over the engine running. It has a cold air kit, Mac Shorty Headers and an X-Pipe. It passed Inspection with flying colors with Cats on it so it's prob not getting "Blow-By" past the rings.
TX21 - I'm in Mesquite.
DTM-Motorsports I Put a mechanical guage on for the oil pressure. Stock temp guage says it is running cool.

TX21 said:

Where are you located? I have a similar problem. My car starts and idles fine when cold but after warmed up I have to hit the gas to keep it running. I have swapped throttle bodys, IAC's, tried the plate between the IAC and the throrrle body. Got some oil in the intake though no idea why.

Click to expand...

oil in the intake is probably due to a bad PCV sys. if there is enough oil in the intake it could be gumming up the valves and causing them to stick. I had this problem a while back and have since closed up the PCV sys. and just run breathers.

projectPONY said:

oil in the intake is probably due to a bad PCV sys. if there is enough oil in the intake it could be gumming up the valves and causing them to stick. I had this problem a while back and have since closed up the PCV sys. and just run breathers.

Click to expand...

Yeah thats what I thought. I pulled the PCV and its working. I may just get a new one because its so cheap.

So a buddy was helping me last night and suggested I should rotate the air mass upside down. I figure what the hell lets try it and bingo, it almost solves the problem. It still sputters for a sec and died on the freeway off ramp but its 90% better. Gonna jack with it some more this weekend.

I'll Try that too.

What the hell. I'll try the rotate thing too. TX21 - Let me know if you find any other things that help. Im gonna be puting Steeda Caster/Camber plates on this weekend too. The car was lowered and wears the shit out of the front tires.http://www.dfwstangs.net/forums/images/smilies/amish.gif

Found some helpful info.

Well I found some helpful info I'm gonna try this weekend on http-//www.muscularmustangs.com

1. How to clean MAF Wire element.
2. Reset the base idle.
3. Set Throtle Position Sensor (TPS) voltage.

Cam_Stang said:

Well I found some helpful info I'm gonna try this weekend on http-//www.muscularmustangs.com

1. How to clean MAF Wire element.
2. Reset the base idle.
3. Set Throtle Position Sensor (TPS) voltage.

Click to expand...

My TPS was a bit off as well.

Fixed!!!!!

One of the things I found on http-//www.muscularmustangs.com fixed my problem!:arms:

1. How to clean MAF Wire element. (DONE)
2. Reset the base idle. (DONE)
3. Set Throtle Position Sensor (TPS) voltage. (Need a volt meter to do)

Cam_Stang said:

One of the things I found on http-//www.muscularmustangs.com fixed my problem!:arms:

1. How to clean MAF Wire element. (DONE)
2. Reset the base idle. (DONE)
3. Set Throtle Position Sensor (TPS) voltage. (Need a volt meter to do)

Click to expand...

Which one?

Probably cleaning the MAF Wires

TX21 said:

Which one?

Click to expand...

Probably cleaning the MAF Wires. The car has a cold air set up and the KnN oil is notorius for getting on the wires and confusing the computer. I just pulled that section of the air intake off and sprayed it with B12 carb cleaner and let it air dry. I also cleaned the carbon build up on the throtle body and IAC. Theese were all simple maintenance things so I did all of them, so i'm not sure which one actually fixed it.