BMW 128i cold start issues

[Bimmer128i]

So, I have been experiencing some odd behavior when cold starting my car for a few months now. When first starting my car in the morning the car will stall if I don't give it gas or throw it in reverse. Also the cars idle will bounce around. Once that is finished the idle will stay around 600rpms and the car will shake badly. If I don't keep my foot on the gas at stop lights the car will go into limp mode. But as the car warms up it drives fine? Last time this happened I only got a misfire on cylinder one code pulled. I also have a catalytic converter code:002C9C. I figured it was the VANOS solenoids so I replaced those with the duralast solenoids from autozone.The previous owner had put the 30$ Amazon ones in and I didn't notice any change but my Vanos code did go away. I'm thinking maybe it still has something to do with the Vanos system but I'm not sure.
Any help is greatly appreciated!

Car Info:
Year:2008
Mileage:129,000
Mods:3 stage intake, AA headers, cold air intake, and StageFP tune.

[///Makis]

Originally Posted by Bimmer128i

So, I have been experiencing some odd behavior when cold starting my car for a few months now. When first starting my car in the morning the car will stall if I don't give it gas or throw it in reverse. Also the cars idle will bounce around. Once that is finished the idle will stay around 600rpms and the car will shake badly. If I don't keep my foot on the gas at stop lights the car will go into limp mode. But as the car warms up it drives fine? Last time this happened I only got a misfire on cylinder one code pulled. I also have a catalytic converter code:002C9C. I figured it was the VANOS solenoids so I replaced those with the duralast solenoids from autozone.The previous owner had put the 30$ Amazon ones in and I didn't notice any change but my Vanos code did go away. I'm thinking maybe it still has something to do with the Vanos system but I'm not sure.
Any help is greatly appreciated!

Car Info:
Year:2008
Mileage:129,000
Mods:3 stage intake, AA headers, cold air intake, and StageFP tune.

Have you changed the plugs and coils recently?

If not did you change them for cylinder 1?

I wouldn't trust any of the solenoids other than OE or OEM. But if the code went away it couldn't hurt I guess.

Try unplugging the maf the night before and see if that changes how the car starts during cold start. If so then I think it points to something like a failed sensor or electronic like coils.

I'd also check the eccentric shaft sensor to see if there's any oil underneath. I think if the sensor failed or is failing that would lead to poor idle but I think it would also run poorly and not alleviate if you pushed the gas but I could be wrong.

What are you using to read the codes? Is it bmw specific or a generic code reader?


I don't know much about the cat code but I think someone posted about idle problems or running poorly after install, not saying that's the culprit, how long after the headers install did the idle problem happen?

Also is there a tune?

[Bimmer128i]

Originally Posted by ///Makis

Have you changed the plugs and coils recently?

If not did you change them for cylinder 1?

I wouldn't trust any of the solenoids other than OE or OEM. But if the code went away it couldn't hurt I guess.

Try unplugging the maf the night before and see if that changes how the car starts during cold start. If so then I think it points to something like a failed sensor or electronic like coils.

I'd also check the eccentric shaft sensor to see if there's any oil underneath. I think if the sensor failed or is failing that would lead to poor idle but I think it would also run poorly and not alleviate if you pushed the gas but I could be wrong.

What are you using to read the codes? Is it bmw specific or a generic code reader?


I don't know much about the cat code but I think someone posted about idle problems or running poorly after install, not saying that's the culprit, how long after the headers install did the idle problem happen?

Also is there a tune?

Ya, I did the plugs and coils not too long ago. But, I partially fixed the issue I believe. The idle is way more steady now. I guess the connector clip for my vanos solenoids was missing and the plug wasn't all the way in??? Also, yes the car is tuned, the tune is from Bob over at StageFP. Also the issue didn't start until the tune.