Need help! Stang will start, but dies...ROUND 2

[KDub]

Here's the first thread:
http://forums.stangnet.com/showthread.php?t=412227
Thanks to everybody for helping out, but I'm still stuck.

I replaced the IAC (Thanks WRXracer!) and unfortunately this didn't fix the problem.
I went out and bought an OBD2 Scanner, plugged in and there are NO TROUBLE CODES PRESENT!
I'm out of ideas besides maybe the MAF, but wouldn't I get a trouble code?
Dont know if it matters, but the check engine/MIL light DOES NOT come on.
Does anybody have any advice?

Thanks
Kevin

 

[COramprat]

I had one of the hoses from the air intake to the throttle body or valve cover...I don't really remember...come lose and caused the car not to idle. It would run as long as I gave it gas but would die as soon as I let off. You may have a vacuum leak somewhere but that is a guess. Hope you get it solved.

 

[ShadowGT]

Here's the first thread:
http://forums.stangnet.com/showthread.php?t=412227
Thanks to everybody for helping out, but I'm still stuck.

I replaced the IAC (Thanks WRXracer!) and unfortunately this didn't fix the problem.
I went out and bought an OBD2 Scanner, plugged in and there are NO TROUBLE CODES PRESENT!
I'm out of ideas besides maybe the MAF, but wouldn't I get a trouble code?
Does anybody have any advice?

Thanks
Kevin

I know that if there is any leaks around your MAF that the car will start but won't idle or run. Once my pos cai came loose by the MAF and my car did exactly as you are describing.

 

[KDub]

I had one of the hoses from the air intake to the throttle body or valve cover...I don't really remember...come lose and caused the car not to idle. It would run as long as I gave it gas but would die as soon as I let off. You may have a vacuum leak somewhere but that is a guess. Hope you get it solved.

I don't seem to have any loose hoses. Just to clarify, it will still shut off a few seconds after starting, even when giving it gas. Thanks for the help!

 

[KDub]

I know that if there is any leaks around your MAF that the car will start but won't idle or run. Once my pos cai came loose by the MAF and my car did exactly as you are describing.

Just went to check everything around the MAF. Nothing is loose.
Thanks for the suggestion!

 

[JonJon]

Maybe that replacement IAC wasn't working since it was used?

 

[KDub]

Maybe that replacement IAC wasn't working since it was used?

Could be, but it only has about 25k on it and was only removed from the car because he had to use a different one after the blower. I'm not experienced with this, but wouldn't the code reader tell me if I had a bad part somewhere? What can the problem be if I don't get any trouble codes?

 

[JonJon]

Could be, but it only has about 25k on it and was only removed from the car because he had to use a different one after the blower. I'm not experienced with this, but wouldn't the code reader tell me if I had a bad part somewhere? What can the problem be if I don't get any trouble codes?

Aah, ok. Just throwing that idea out there. I don't know if any codes should be thrown, replacing mine fixed my idle problem.

sorry.

 

[KDub]

Thanks for trying.

 

[PG98GT]

Still seems like a vacuum leak. I, like others that responded here had that problem. Mine was the rear hose that comes off the rear of the aluminum upper intake. The hose had started cracking around where it slips over the fitting. Used tape as a quick fix/check and the car stayed running. I cut that cracked part of the hose off and put it back on...no more stalling. Hope yours ends up that simple.

 

[forpit2000gt]

check the voltafge on the tps. Usually your problem would be bad IAC. Do you have a friendthat you can swap the MAF, IAC and tps? do one at a time. MAF will usually give some kind of code. TPS or IAC will not necessarily. Still check all vacume line. If you give it gas, does it try to rev??If not , TPS is next.

 

[KDub]

Still seems like a vacuum leak. I, like others that responded here had that problem. Mine was the rear hose that comes off the rear of the aluminum upper intake. The hose had started cracking around where it slips over the fitting. Used tape as a quick fix/check and the car stayed running. I cut that cracked part of the hose off and put it back on...no more stalling. Hope yours ends up that simple.

Hopefully I'll find a cracked or loose hose. That would make my life easy. Have to wait til there's light outside.

check the voltafge on the tps. Usually your problem would be bad IAC. Do you have a friendthat you can swap the MAF, IAC and tps? do one at a time. MAF will usually give some kind of code. TPS or IAC will not necessarily. Still check all vacume line. If you give it gas, does it try to rev??If not , TPS is next.

Unfortunately I don't have somebody close to swap parts. I have 2 IAC's now and I don't think both are bad; 1 having 52k and the other 25k.
When I give it gas it will rev, but the car still only stays on for a few seconds even when revving. I'll get out there and check the TPS in the morning.


Thanks for the advice guys.

 

[forpit2000gt]

maybe you already said it , but did you have the fuel pressure checked? The fuel pump will come on when you turn the key and then when there is pressure, cut off. When you crank, the fuel pump runs continuously. Maybe check that direction . There is a lot more to it but you get the idea.

 

[stang09er]

Do you have an aftermarket differential??? If your speedcal is not powered correctly, you WILL definetly have a problem trying to keep the car running. i noticed that my speedcal has a red light that comes on when it is powered. intermittent or no light at all = no idle or corrected speedo

 

[JB9789]

Try just unpluging the MAF before you start the car some times there are programmed maps that will let the vehicle run and make sure that there is nothing weard like
anything blocking air flow(like a plastic bag )thru the filter or the pipe to the idle air
control valve being blocked or your theft system light flashing.

 

[KconoverK]

Is your theft light blinking??? I had this problem after I had it worked on, there is a ring that goes around(in the sterring colum) where the key goes in its for the theft system, mine seperated and it would not let the car start. even when you had the car at half throttle. hope it helps!

 

[KDub]

Is your theft light blinking??? I had this problem after I had it worked on, there is a ring that goes around(in the sterring colum) where the key goes in its for the theft system, mine seperated and it would not let the car start. even when you had the car at half throttle. hope it helps!

No, the theft light doesnt blink until I open the door....Can you elaborate on this? How do I fix it? I didn't even really think about it...

Thanks!

 

[Zorro]

I agree with JB disconnect the maf sensor and try starting the car. I have had a problem with mafs overfueling the engine by commanding to much load when the vehicle is just idling. Disconnecting the maf allows the pcm to go into a default mode. If that does'nt work find a way to retrieve those codes stored in memory. Because whatever is causing that check engine light on to stay on is the most likely the cause of your concern. Good Luck!

 

[KDub]

I agree with JB disconnect the maf sensor and try starting the car. I have had a problem with mafs overfueling the engine by commanding to much load when the vehicle is just idling. Disconnecting the maf allows the pcm to go into a default mode. If that does'nt work find a way to retrieve those codes stored in memory. Because whatever is causing that check engine light on to stay on is the most likely the cause of your concern. Good Luck!

I tried it with no luck. The check engine light is not on and hasn't been.
All I should have to do to retrieve those codes is hook up and hit the link with my scanner, but I get nothing...

 

[Zorro]

Does it still die? If not is seems as it may be an intermiitent concern. I am here in Bellflower, California I don't know how away we are but I am a ford tech. I'd be happy to help you out if you are in the area if not well get those codes read.