Very noisy fuel pump and surging

[Chris Wilson <chris@maximum-bhp.u-net.com>]

1987 Audi 200 Turbo 2WD. 80K miles.Fuel pump noise started about 2 
weeks ago,now _very_ noisy.Wife complains of surging and poor 
performance at high to full throttle openings.I drove the car and it 
seems to be boost related."Gauge" shows 1.4 / 1.5 bar boost maximum.At 
high boosts the surge is apparent,and performance is sluggish.At 
cruise the car seems normal.Sometimes the surge is gone and car 
performs normally.Boost still reaches circa 1.4 bar.

Questions: Is there a known fuel pump problem with these cars?Is boost 
solely controlled by air pressure to the wastegate,or is there 
electronic control? How is overboost,(say a stuck wastegate or pipe 
off),handled? At what boost should the failsafe device operate?How 
accurate is the "gauge" considered to be?Ie should I put a remote 
proper boost gauge on for diagnosis?

A quick other problem.The dashboard water temp gauge was 
intermittent,now permanently broken..:-( Does the gauge sender control 
_just_ the gauge,or does it have any other role?I guess this problem 
is totally unassosciated with the above.

Thanks for any input here,the car is in constant usage,and my 
diagnosis needs to be fast and accurate,as has the repair,(or domestic 
strife will ensue...:-) )


-- 
    Best Regards,
                 Chris Wilson
http://www.maximun-bhp.u-net.com
mailto:chris@maximum-bhp.u-net.com