Nitrous
New member
I did a tune up last weekend with UR5 plugs gapped to .035" but will probably pull and change to .028"-.030", NAPA Premium brass cap and rotor, Premium GM plug wires, new fuel filter and new vacuum lines where needed and cleaned the K&N. I also unplugged the ESC wire and set the timing at 0 and set the fuel pressure regulator at 50psi with the Ultimate Chip at 0. Now when decelerating (letting off the gas) to a coast I get some erratic idling and boost fluctuations. I still have the original Idle Air Control and TPS and it almost acts like so I'm thinking a bad IAC or some carbon buildup. When I pulled the air filter off to clean it I pulled the whole tube and this is when I found the turbo to have a few of the I impeller inlet blade tips missing like it had touched off or something small went through it. Now after the tune up the truck seems to be running a little rich at idle with the Ultimate chip set at 2. I need some tuning S/W and a wideband to really see what's going on but thought I'd ask a few questions before I proceed. BTW, the turbo still spools with no issues but I'm replacing it anyway and I'll rebuild the worn out one and save it as a spare. Thanks for any feedback..............:tup: