For the past week or so, about 90% of the time there’s no throttle blip when I start the car. In other words, instead of the quick little 1400 rpm blip, it just slowly limps up to 800 rpm. Is this a sign of bad things to come (i.e. some worn part about to fail or something?). In the entire time I’ve owned this car, this is the first time it’s doing this.
Any thoughts?
Thanks.
can you make a video and post it up? i.e. what does limp mean? To me that means it starts at an abhorrently low rpm and slowly and barely crawls up to 800 over a period of time. Would be better if we could see it. Is this a cold start phenomenon or all the time?
Anyway, I’ve never heard of this happening. I also haven’t heard of B7 starter problems.
Mine just started this on Monday after I picked the car up from the shop following a wheel and oil change. Then then back to normal this morning.
No idea why, google won’t tell me.
Limp as in it goes up to 800 rpms in 1-2 seconds as opposed to going to 1400 rpms and then dropping down to 800rpms all in 1/2 a second. Sometimes it feels like it might stall halfway up to 800 rpms. It happens mostly on cold starts but it’s happened on warm starts a few times as well (and a couple times since it’s started occurring, it blipped properly on a cold start). Car is parked underground so it’s usually about 10-15c.
make a video
Sounds like something fueling related, like a bad filter or weak pump. How does it drive?
This was happening when my fuel pump was dying a few years back.
Also check for any vacuum leaks
Also could be a weak battery
I wonder, why does it even have to toss the RPM’s up so high like that? Is there really a purpose for that? I find it annoying when I start my car late at night and I get a nice 1500 rev to wake the neighbors.
/threadjack.
Idk why but it’s one of my favorite parts of s4/rs4 ownership, that cold blare that pops and spits. You should hear a Catless c63 if you want to hear crazy start up lol
well, it’s interesting to note that Axel’s JHM supercharged B7 S4 avant IS having some weird fuelling idiosyncracies that JHM is trying to work around in the tune.
I wonder if it is indeed the fuel pump per 91GL’s recollection of his own problems.
Could be anything of course. Just interesting to note the two things may not be mutually exclusive.
One thing i remember from 91’s experience was NOT to buy an aftermarket fuel pump. Hopefully he can clarify his advice on that matter if it is indeed in need of replacement.
Yes the stock pump is strong but it has a shelf life, if it is the pump, oem is best. I replaced mine with that 034 drop in garbage and just opened up a can of worms. I’m sure that’s what caused alot of my motor problems. I had warned vwrcr to not do one but he did and blew his motor.
Axel
Good that you posted this here. There isn’t anything wrong with your car… when I had the S4 at my house I would keep it in my heated gargae the result was no blip on start up. When I had it at my friends house it was outside and depending on the temps it would blip on startup
With the JHM tune your oil pressure and the outside temp will signal your car to either iddle high or to just low iddle … it always seems like its going to stall at low iddle due to the idle stabilization that happens on the b7 cars on start up… You know the woot woot that normally happens.
So if your car dosnt require a iddle blip on start up that’s good. Bigger injectors might make it more noticable and the odd b7 fuel issues don’t help… I remember I needed a pump adjustment when I got headers… seems the b7 cars are just funny that way.
All In all sounds like your ok and there is nothing to worrie about you should even feel better that your car isn’t requesting the higher rpm on start up. Start-up is the most crucially important time when it comes to motor ware so having the car keep the low rpm is good. It should mean your oil pressure is good
Ok, but this used to never happen, regardless of outside temp or engine temp and now it’s happening a lot, again regardless of outside temp or engine temp.
[quote=“91gl,post:12,topic:2979”]
which pump?
Battery is 5 months old so I doubt it.
Without the start up blip. This shows it just get up to 800 rpms. It’s not a bad one though. Sometimes, it feels like it’s not going to make it to 800 rpms:
With the start-up blip (what I’m used to seeing):
This afternoon, the car almost didn’t start. I think my starter is on its last legs…
The vids were so short I blinked and missed the first one lol.
Not sure why there is a difference upon start-up. Usually, on stock calibrated ECU’s the idle rate is based on a combination of things like ambient temp and how quicly the SAI can get the pre-cats to an “emissions acceptable” temp. Maybe the tune is the cause but either way I don’t think it’s an actual problem or causing any type of damage. Not sure if the S4 has the SAI like the RS4 but the initial high idle on most OBII cars is usually emissions related.
Axel
Its just the start over shoot. Its normal but it dosn’t happen every time. Its ok for this to not happen. Stock you get a blast of air to help get the car motor started. To do this the ECU gives extra RPM. You have a blower so chances are when you start there is a blast of air from the blower making this less needed.
I wouldn’t look at this as something that is an issue. So yes this is normal. Also the fact that your car will do it sometimes and then not others just says your car is doing it when it needs it.
Being a Audi tech Ive seen this happen ALL The time. Some cars blip the RPM’s to 1800 on start. Some other cars never get past 1000. Just depends on that cycle start and what the requirements are at that start.
who said computers couldn’t think for themselves, its terminators all over again