Fuel pump?

B5 S4/ RS4
#1

So an interesting/annoying phenomenon has popped twice in the past month or so. My car does not like lower gears (2-3) for extended periods say on slow winding mtn roads (been looking at new homes/property away from people). Twice now after periods of maybe 45 min - an hour the car just says nope I’m done and cuts out. If I let it set for a few minutes it will fire back up and on my way again. But, it will cut out again shortly after. Eventually after a couple cycles like this it acts completely normal and gets me home no problem. Also prefers to be level ground to rest and get going again (not always possible). Also, Plenty of fuel in the tank both times.

044 in tank pump. Normal noisy sound gets elevated during these instances.

Any ideas/helpful advice? Thanks. I need to get in the tank and make sure all is normal and see what’s going on. I did not install it. Came with the car from PO.

#2

Have you replaced you fuel filter recently…or ever?

#3

Yes. It has been replaced within the last 5k miles. Thought of that too, but shouldn’t be an issue, I don’t think? Would make sense though.

#4

might not be fuel related?

#5

Sounds like the pump might be cavatating… or starving for what ever rrason…the pump noise tells you something is wrong… maybe its pulling in tank debris as the car would be sloshing alot…also maybe look into a vac leak or pressure leak from the tank as that would do it as well

#6

Got into the tank, removed the pump and no evidence of any tank debris. Previous owner did a proper job with install. Used the 034 drop in V8 basket option.

Since it is out I have ordered up an in tank pre filter sock. Hopefully will lower the pickup point as the current setup is a little higher from the basket bottom than I would like.

Doubt this will solve my phantom issue but what the hell.

#7

More insight…

#8

Perhaps the fuel pump noise is correlated but the pump itself is not the cause, or maybe the fuel system is not related at all.

Could just as easily be an electrical problem such as a loose ground, sensor starting to fail (ie. crank position sensor), short, corroded contact, etc.

Driving in lower gears/higher rpm on a mountain road for instance can produce both more heat in the bay and more vibration.

#9

Very true. Will continue to monitor. Thankfully the issue has been very isolated but obviously want to resolve it for good eventually.

#10

almost sounds like a crank sensor problem to me. it shows the symptoms of it for sure.

#11

Thanks. I’ll scan today. Not sure why I haven’t already? Prolly that false sense of security of no cel, I should know better.

How’s that build coming along? Should be all buttoned up by now, no? :smiley:

#12

Not really a build :wink: just bolt on stuff…lol.

#13

No pending stored codes aside from intermittent charge pressure neg deviation. Nothing for cps…fuel pump is buttoned back up. Added a fuel pickup sock filter to the 044 in tank and did away with the basket. Lowered the pickup point a fair amount. Taking the car up to the same tight twisty road and conditions to do a little research and testing…