I'm having a strange idle issue....when I start the truck sometimes it will start up and idle just fine, other times it will start hard and not want to idle worth a damn. I figure it's the IAC Valve (bought it but haven't changed it yet...no returns on used electrical parts...if this isn't the problem I want to be able to retun the part cause it was $100)

I am also having a really wierd electrical issue...when I drive at night my headlights will "flicker", they won't go completely out or anything but they will dim for just like 1/2 second or so....at first I thought I was seeing things until my friend asked me if my headlight were having seizures. It's only the headlights...no other lights do it EVER and the amp guage doesn't move so I don't think it's the alternator, it it possible it's a bad ground to the headlight circuit ???

anybody got any ideas ???

 

Some times, cleaning out the throttle body helps idle quite a bit. On the headlights, follow the wires and check for any splices or melt marks.

 

I tried cleaning out the TB...I even took out the IAC and cleaned it (pretty nasty)...it seemed to help but it is still doing it a little

 

Pull the vacuum line off of the fuel pressure regulator after it sits overnite. If any fuel comes out of the vacuum line time for a new fuel regulator. Happened to me.

 

Exactly what I was going to suggest!

 

fuel pressure regulator GM part# - 17113678 $9X dollars if I remember that mistake right.

 

Thats the one! I am pretty sure that the problem.....it was when I had the same staring issues.

 

sheesh...another $90 part

I will check out the line in the morning......just to be sure...where exactly is the FP regulator ?? (I know it's on the fuel rails but where exactly)

 

I think you can get just the regulator for less.

Its on the driver side fuel rail, goldish in color.

 

It's the half dome looking thing clipped on the driverside fuel rail with the little vacuum line running to the top of it. Know what I'm talking about?