Hoping someone here might be able to help me out please. My car is a '98 UK spec with PPP. Every now and again, especially after a hard run, but not always, the idle speed drops so low the car cuts out. The idle speed usually remains quite stable under normal usage. Looking at the various threads I get the impression it may be associated with the Air flow meter, which I understand is located below the panel filter and may get contaminated with oil. My dealer has recently looked at the fault but could detect nothing wrong, presumably by the diagnostic checks.

I was also wondering if the following may have something to do with it. The car is fitted with a DTA valve, don't know which one, but if the diaphragm was failing, might this cause the said problem. When the car is accelerating there is quite a loud whistling sound from the drivers side (is the DV diaphragm leaking), and then the usual whoosh as you change gear, presumably the PPP generates a higher boost figure over std. The Bailey's twin piston dump valve suggests that this might help cure problems with erratic idle, when fitted to cars with Air flow meters. I do think that the car is underperforming on acceleration, if the DV was faulty would this effect the performance greatly. Sorry for the long post but I would be grateful for your views.

 

vta dump valve wld be first suspect then maf