Advice on VagCom code and bad running

[newsh]

Car is a 3B, RS" spec MRC mapped, missfires badly at anything other than very small throttle opening. At medium throttle boost comes up then drops then comes up again etc as if ECU boost control is being switched on and off.
If car is held at fast idle seems like the ignition is being switched on an off (same thing really).

When the codes were pulled the engine was not running and the Lambda was unplugged so I guess its just the 00533.

Control Module Part Number: 857 907 404 B
Component and/or Version: MOTOR PMC 1
Software Coding: 0261200453
Work Shop Code: 1267356261
3 Faults Found:
00533 - Idle Speed Regulation
10-10 - Adaptation Limit Not Reached - Intermittent
00525 - Oxygen Sensor (G39)
03-10 - No Signal - Intermittent
00513 - Engine Speed Sensor (G28)
03-00 - No Signal

[UrS4boy]

What is the state of your 3B distributor? Cap okay? Shaft play? Rotor okay? Wires all good, no arching (check at night in the dark). Definitely start there before looking elsewhere (throttle body potentiometer, MAF, etc).

[newsh]

Dizzy is good AFAIK, new rotor, new cap, new metal gear. I'm told timing has been checked and double checked. This is not my car BTW and is not local to me so I can't pop out and have a look at stuff.

[Rusty]

ECU earth points on the IM? BTDT

[Mikes2]

Page 1-30 of

http://s2-audi.co.uk/workshop/3b_ignition/3bi.pdf

N71 (ISV) jammed open or closed or bad contact

or G70 (MAF) - air leak between N71 / G70

[prj]

Page 1-30 of

http://s2-audi.co.uk/workshop/3b_ignition/3bi.pdf

N71 (ISV) jammed open or closed or bad contact

or G70 (MAF) - air leak between N71 / G70

Except the ISV has nothing to do with the problem at hand. The code is a side effect, not the cause.

Check all grounds to ECU, do a full pressure test, check the plugs, make sure all the coil wires are good.