Rough idle at start-up after intake install

[rkdiddy]

Let me start off by saying I have a Frankenstein intake (AWE filter with APR intake tube). I've had this setup for a few months and have noticed when I start the vehicle (cold start) while warming up and after the initial drop in RPMs, the engine seems to drop so low that it sounds like its going to stall. Then it 'saves' itself and starts ideling correctly. I thought maybe the ECU needed to adjust, but it never has.

Has anyone else had this issue? I borrowed my brothers VAG com, but didn't see any errors.

[thebishman]

Happens to mine every time after the first start up of the day when cold. I consider this 'normal'. My car is stock with 17,500 miles on it btw.
Bish

[Bkitch89]

I had this problem when i had my b7 a4 but it was doing it even after the warm up. when i came to a stop the rpm would be so low it almost shut off.. i took it into the dealer and it happened to be carbon build up.. id take it to the dealer if you have a warranty.

[compguy]

My car used to be rough after a cold start first thing in the morning especially on really cold days. Like the OP says, it almost stalls and then recovers. Complained about a year ago (last winter) and the dealer said nothing wrong. Complained again this year and they put new ECU software in it. It doesn't do it anymore. But what it does now is that the cold start is clean, no issues, but if you pull away real quick from a cold start with a bunch of throttle you get a small stumble, once and then it goes good from there. At least that's what I see on my car. It is an early build 2010.

[Deep Sea S4]

Cold start, bunch of throttle you're going to get stumbles for sure no matter the type of car.

There are a lot of things happening in a cold start up and a lot of fuel being dumped into the engine. You never going to get smooth engine response on a cold engine.

I am not a proponent of long warm up periods (more harm then good IMO) but before I drive away I always wait for it to come off of the high idle and settle into its normal rpm idle speed.

[Nighthawk]

How do long warm up periods do more harm than good? I guess it would make sense that it warms up faster under load, but is there really hard being done? How about just long normal idles?

[Deep Sea S4]

Oil temps will take a very very long time to reach optimal temps for engine protection sitting in a driveway idling away. I assume that most people who allow cars to idle in the cold for a long time are concerned about one of two things, wear and tear on their engine or wanting hot air to blow from the HVAC unit. Either way both will happen much faster and far more efficiently with smooth driving on a cold engine. The advent of synthetic oils have made huge strides in allowing oil to flow faster and reach internal components within your engine. Once a car has reached normal rpm levels in the cold drive off slowly and your car will warm up much faster. Just my opinion

As far as extended idle at any temp, especially in the summer hot months doesn't that place a large strain on the various components of the engine. I avoid it, drives me nuts to see people sitting in their cars for 30 minutes with the AC cranked and not moving. Horrible for the environment as well. I'm far from a tree hugger but that just makes no sense.

[Nighthawk]

Thanks.

[compguy]

None of my older FI GM cars stumbled when cold at all. In fact they ran stronger the colder they were, not that I make a habbit of giving my cars a lot of throttle when cold. Also prior to the new software it wouldn't do that although it would stumble right after the cold start.

Overall I like the new calibration better because I don't need worry about the car stalling.

Cold start, bunch of throttle you're going to get stumbles for sure no matter the type of car.

There are a lot of things happening in a cold start up and a lot of fuel being dumped into the engine. You never going to get smooth engine response on a cold engine.

I am not a proponent of long warm up periods (more harm then good IMO) but before I drive away I always wait for it to come off of the high idle and settle into its normal rpm idle speed.

[sf_loft]

I'm glad I live in California. Don't miss those cold ice scrapping moments back in NY.

[rkdiddy]

Thanks for the feedback. To clarify, when I mean warm up - I'm simply referring to from when you start to the car until it drops RPMs. Typically takes about 20-40 seconds. This is where the issue is happening. After this is complete, I will hit the road, but take it easy until the car is at normal operating temp.

I think I'm going to uninstall my intake to see if that fixes the issue, if not I will take it in for service. Cheers.