seems the MAF on the right bank was at fault, found a replacement BOSCH MAF to swap and seems to have cured the cold start rough idle hunting, which went once the engine was to temp ,

so time to find x2 new BOSCH MAF sensors and replace the original units

bit at a time

BB

 

do you need to buy 2x?

 

i got a 'spare' used one to test my theory , two new ones have now been purchased to permanently change over,

genuine Bosch units which are used in Many Many different Brands of car, its only really the mounting tube that differs for each manufacturers requirements , the sensor is easily removed and swapped into the Bentley intake tube ,
car fired right up from 'cold' ( English summer time at 21deg C) and settled right down

previously ( and intermittently ) the car would go into a loop of idle revs pulsing up and down , throwing codes for the right bank all cylinders fault amongst others, BUT as soon as the car got to 90degC on the dials it would settle right down and be fine for the rest of the running, but MPG was not good ,

hopefully with a matched pair of new MAF sensors fitted it will all be running much better ,

i will take some pics and put up part numbers of the sensors only ( not the whole MAF tube with sensors )

BB

 

The removed Duff unit , as can be seen the sealing to the 'chip' insert has gone bad, no idea if it relates to its performance, but changing it out has cured the rough idle from cold start ,

as can be seen , a Genuine BOSCH unit , and very generic in where it is used in most VW and Audi intake systems, no matter how many cylinders, petrol or diesel, and how many CC's , just match the part number

BB

 

Nice,

"i will take some pics and put up part numbers of the sensors only ( not the whole MAF tube with sensors )"


It's not always the "whole" sensor........ I never thought of it and usually replaced the whole thing myself.
Also, I said you always replace 2x, is wrong. When you have a proper analyzer, you know exactly which to replace....

Cheers,
~ZaOs~