Diesel Runaway

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panic-mechanic
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Re: Diesel Runaway

Post by panic-mechanic »

Shutting off the ecu opens a valve that is normally closed with th ecu switched on, which allows vacuum from the mechanical vacuum pump attached to the cam to suck on the ASV. So as long as the engine is rotating that pump is pulling a vacuum that closes then ASV. When the engine eventually stops running the ASV get no vaccum anymore and snaps open. When you switch the car on again the ecu closes that valve and voila no closing of the asv.
Stephan van Tonder - Jhb - Putfontein Benoni
'05 Audi A6 3.0L TDI Avant
'09 Touareg 3l TDI
'13 VW CC 2l tdi (repair project)
'05 Touareg v10

Perfect Power dealer. I do dyno tuning.
billionairebum
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Location: Randburg

Re: Diesel Runaway

Post by billionairebum »

panic-mechanic wrote: Wed Aug 15, 2018 11:23 am Shutting off the ecu opens a valve that is normally closed with th ecu switched on, which allows vacuum from the mechanical vacuum pump attached to the cam to suck on the ASV. So as long as the engine is rotating that pump is pulling a vacuum that closes then ASV. When the engine eventually stops running the ASV get no vaccum anymore and snaps open. When you switch the car on again the ecu closes that valve and voila no closing of the asv.
That is a fantastic explanation thank you.
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