vibration in steering, stalling/idle and surging

[mac20015]

I live in the uk I have a GC limited 1999 (4.7l v8)and have three issues

1) Idle when its cold it does not idle properly stalling when you put it in gear - is this the fault refered to here as the IAC motor?
2) Surging - Say on a long journey when you'll be doing maybe 80-90mph on a motorway for a period the revs start surging (rising and falling by maybe 300 rpm) this means it start hunting for gears on hills and then once you come to stop the revs will sometimes remain at say 1800-2500rpm
3) in the last week since having two tyres fitted and the tracking done I now get steering vibration under braking

Any ideas?

James

[dksob81]

1 - almost deffinate Idle Air Control Valve (motor) failure.

2 - could be numerous things. possible IAC staying open/adjusting, Throttle Position Sensor - fluctating the gas flow. as for the high idle - IAC.

3. how long after having this done (tires, tracking?) did this start?

[mac20015]

1) thanks
2) Thought it might be the same
3) almost immediately if not immediately, I know the tracking is a bitch to do as the front suspension isn't really very modern design wise and I think the tracking and tyres is a bit of a red herring. I raise this because there is a few quotes kicking around the web about warping brake disks particularly on 99 models. It also has acquired a mild tug to the left under braking too.

[dksob81]

Yes the brake rotors warping is what I was getting at, the 99 -00 or 01, have it real bad because the rotors weren't designed well and get hot real quick causing them to warp, also just like any vehicle if the wheels are tighten to tight this will also cause the rotors to warp, but ussually won't warp so early maybe within 1000 miles or so of them being tightened.

I would start with checking all the bolts to make sure they are tight -
Brake calipers***
Tie Rod Ends
Steering Stabizer (damper)***
Wheels (80-110 ft. LBS, I always torque mine to 95 ft.lbs.- right in the middle)

I'm sure someone else will post in with some other possible things to check for tighteness.

OK, thats a good place to start. let us me know what you find out then we will take it from there.