My truck starts and runs well when cold.slightly after about 15 minutes of driving, I'll be at a stoplight and she idles good ....then all of a sudden , she'll start to miss then stall. She'll be good at the next light , then without warning it will do it again. I have to put it in neutural to keep the rpms high, then put it in gear and take off. It seems like it only happens when its warmed up.I cleaned the mass air with no results. Truck has about 40K. Any ideas??

 

Sounds like IAC (Idle Air Control) valve is dirty or needs to be replaced.

 

Could also be the TCC solenoid, it's part number F81Z-7G391-CA, availible from your dealer, about $150, install it yourself. Check the IAC first, but if that's good, it's prolly the solenoid trying to keep the converter locked even when you come to a stop (stuck open VFS), it's more likely to happen when warm and is caused by micro-contamination in the spool.

Hope this helps,

G

 

I've already tried to clean the IAC valve, but I heard many times that you may have to replace it instead. What about the 02 sensors? Could that be the issue in open loop? Thanks in advance.

 

Anybody?

 

try checking the fuses for the pcm (40 amp maxi fuse) my truck was doing the same thing and would give no warning symptoms. when i started it up in the morning it would run extra rough because of the loose conection . i too replaced the iac , i also did plugs and a battery (ineeded those two though) and a key transciever.
the only thing that was different is that i was also getting theft trouble codes.
you never know just check em' for the hell of it

 

I really think this is the problem....

 

Factory Tech- Your theory sounds right, except for the fact that it does it in Nuetral too. I can put it in park and it will do it as well. It comes after ideling and only after warm-up. It will sputter and then idel as if it was running on 4 cylinders. As soon as I drive off it will dissapear, but if I give it a little gas in nuetral, it still idles rough. Weird.