storm101

So heres a bit of the story, this is my sister in laws rig, and I have not had much time or access to it since she asked me to check into whats going on, and I am not familiar with the 5.2L engines which leads me to this post

The symptoms seem to be as follows from what I found today, when started up after sitting it seems to run and idle just fine around 400RPM, rev it up it still seems alright but dips below the 400rpm mark, and bounces back up to normal idle, hold the rpms at 2000 or above for a bit (like under normal driving conditions) and let off the gas it seems to get a bit chuggy and instead of dipping below the 400 mark and bouncing back up, it shoots to 0 and either then bounces up to an alright semi normal idle, or just flat out dies and takes a bit to get started, after it stalls it seems to not idle, but still goes alright if you keep some gas on, although a bit sluggish. Also should note the check engine light has been on since she got it, and this issue just started yesterday, so the CEL isnt a helpful indicator on this as it was already on.....(I dont know why its not fixed or hasnt been checked into)

I checked it over a bit, and everything seems to be in alright shape, but the TB really has some gunk build up (i can see it on top of the butterflies, so I assume the rest of it is just crapped up also)

Big questions come here, where do I start with this? Do the 5.2 liters have something similar to the 4.0l IAC in the TB that could be gunked up with that crap I saw? I just dont know where to start with this beast as I have never messed with one before, and also want to get a quicker idea as to what to hit first, considering I dont have too much time around it, and want to make the time I do spend with it quality fix time without me reading for weeks before getting an idea on whats going on.

Thanks a bunch!

1DeadZJ

I would check for vacuum leaks and get that thing to an Autozone and have them scan the codes. Mine had a big vacuum leak on the rubber hose that goes from the PCV to the lower intake.

storm101

where is the pvc located on it? I'll be able to look at it again tonight after work, the cel is something I'll convince her to get scanned next time she comes around here, but vacuum is on the list of things now thanks, any more input from anyone?

1DeadZJ

The PCV valve is located on the passenger side valve cover there is a rubber hose that goes from it to the lower intake. There are a lot of other vac lines running around though so don't skip any. Take a can of starting fluid and spray it around the vac lines while the engine is running. When the fluid hits a vac leak the engine idle will change and you know you found a leak.