My truck sat for a couple of days and when I finally went to start it the battery was dead. After I got it started it didnt want to idle' it would start and then immediately die. When I gave it gas it ran just fine. So i went ahead took of down the road with it not letting off the gas. After about 10 minutes of driving it quit dying but when i let off the gas when coming up to a stop i could hear it engine brake for a second and then the rpms would drop down to nothing and then catch itself and rev back up to normal idle. What could it be?

 

Fuel problem for sure. Check your fuel pressure at the rail. Fuel pressure regulator, fuel pump, or in need of a good tune up.

 

how do you ckeck the pressure?

 

There is a little pressure release vavle on the fuel rail. It looks like a larger version of a tire inflation valve. The fuel rail goes around your manifold in a square shape that the injectors come off of. Find the valve (mine is on the drivers side), and unscrew the cap. U can use a tire pressure guage to check the fuel pressure. Use a rag and wear eye protection. Stick a pencil in there to see if its under pressure ie. it'll squirt out.

 

I would have to say you have an AIC issue. Feathering the gas to keep it running is a classic symptom. It is a sixty dollar part. You can also try taking it off and cleaning it. The AIC (air idle control) is located on your throttle body. Very common problem.

 

yup, IAC valve is sticking... on the back of the TB. either it's sticking or going bad. I'll bet you just started having cooler weather too huh?

 

If the batt goes dead the PCM forgets it's learned IACposition. (happens to me sometimes when I forget to turn off the map light)
Once you get it started slowly back off the throttle. The rpm will drop low but if you can keep it running around 500 rpm the pcm should re adjust and learn the IAC.

 

Yeah , the battery did go dead and it never did it until now. And yes it did just start getting a little colder. Sounds right

 

Some one else was just on here where we were talking idle air controler. On the back of the throttle boddy two torx screws and an electrical conection. I had the same prob pulled mine to find it covered with thickblack carbon. You can try carb cleaner or replace. Got mine at autozone I think around $35. Before you go thereit doestake awhile for the PCM to relearn idle, someone on here said that 40mph is the magic number to drive for it to relearn, butI have noidea onthe reliability of that.

 

Srart with the Idle Air Controll valve motor thing.

Mine just Had the same problem and that was the cause.