My truck has been havin a problem... basically when its cold out and I start it its absolutly fine, I let it warm up before I drive and everything but anytime I drive it shut it off for say 5-10 mins and i start it back up the idles are reallllll low 500 and under and goin up and down a little bit, and now a couple times my truck has actually stalled right out when I put it in gear. Ive tried revin it before gettin the rpms up but once I let off it goes back down, now its not all the time, but it is enought to **** me off. Any ideas guys?

 

Dude....I see this a hell of a lot in my shop. Without scanning your truck and seeing any Trouble Codes, I'd have to say it's either your MAF Sensor is bad or needs to be cleaned or your TPS Sensor (Throttle Position) is bad.

Take your MAF sensor of and clean it using some MAF Cleaner or if you don't have that just use some brake parts cleaner and clean the screen and the electrode (don't try to touch the electrode). Then put it back on and start your truck and see if that helps. Let me know what you find.

 

That sounds like the symptoms of a leaking fuel pressure regulator...pull the hose off of it and check for the presence of fuel (fp reg is located in the center of the driver's side fuel rail)

 

hmm ill try cleanin it this weekend, and the fuel pressure reg... do i just buy a fuel pressure gauge and put it on the part under the green cap?

 

Easiest and cheapest way to check the reg is to see if it's leaking. The rubber diaphragm(sp?) in the regulator tears and gives you a rich condition that is most noticeable after a hot soak. I had the same exact problem with mine, and from what I read a while back on GMTrucks.com, it seems to be very common.

If you pull the vacuum line off of it and fuel comes out or it smells strongly of fuel, you've found your problem.

 

hmm Im kinda followin, pics might help tho.. Not to familiar with what you mean.

 

If you look on the driver's side fuel rail on the intake, there's a round, metal thing in the center of it with a thin vacuum line going to it. The vacuum line comes from the top of the intake, under the cover. You can pop that line/hose off by hand, and see if fuel drips out or if it smells like fuel.

 

You can sorta see it in this pic...it's towards the top of the pic, just right of center, with the small blue loom going to it. (next to the bigger blue loom)



*EDIT* yours will not have the blue loom lol

 

I had a similar problem Truck wouldn't idle when the block was cold, sometimes it would stall out while I was driving, etc. Took it to the shop and it was just a dirty sensor. Don't you just love technology

 

thanks guys Ill try all this, this weekend.