Revs suddenly drop, fuel pump? (video)

Hi all,

My Impreza 2.5 TS has been exhibiting some unusual behavior lately.
When revving anything over 2k I can hear a click and a noise that sounds like the fuel pump priming coming from behind me. when I hear the click the revs suddenly drop a couple 100 revs before recovering once the "priming" noise has stopped.
You can see and hear what's been happening in the video below. The issue happens at the beginning and again at the end. The "click" sound should be audible and you can see the revs drop when it happens. What do you guys reckon?

https://www.youtube.com/watch?v=FO5-Fz3A-zo

Tea drinker

Totally guessing but my Passat does a drop like that when it's cold, and the secondary air pump cuts in.
Shouldn't happen on a warm car, you could get someone to listen if the pump is coming on while you raise the revs.
AFAIK the fuel pump should only prime when you turn the key and then stay running while the engine is running.

Tea drinker

Tea drinker wrote: »

Totally guessing but my Passat does a drop like that when it's cold, and the secondary air pump cuts in.
Shouldn't happen on a warm car, you could get someone to listen if the pump is coming on while you raise the revs.
AFAIK the fuel pump should only prime when you turn the key and then stay running while the engine is running.

Thanks for the advice! Yeah I can hear the pump priming every 30 seconds or so, seems like it's struggling to give the engine what it's asking for. It comes on (primes) at low or high revs but only does that "click" noise and rev drop at high revs.

So it seems this only happens when the air blower is on. With it off it never happens. The defrost and AC buttons are off though so I'm still clueless...