slow cold start

[Compman]

Originally Posted by irokwrx

Hey not sure if you still have this issue but I had this issue for about a year. ONLY on cold starts. What fixed it was replacing the brake pump behind the driver-side finder. Super simple replacement. I did a small write-up on "What have you done to your M3 today". If anyone else is having this issue give this a go. BTW I replace every fuel and spark item in my car trying to fix this and the pump did the trick.

Wow I never heard of the brake pump fixing it. Does it leak down the vacuum after sitting a while? What’s it doing to cause long cold starts ?

[irokwrx]

Originally Posted by Compman

Wow I never heard of the brake pump fixing it. Does it leak down the vacuum after sitting a while? What’s it doing to cause long cold starts ?

Yep now you have. Yeah I think the pump leaks, I also noticed a stiff brake pedal when starting now that it's replaced. There was pretty much no solution on the boards that was not tried by me. If you have this problem, give it a go and thank me later....lol.

[Compman]

Originally Posted by irokwrx

Yep now you have. Yeah I think the pump leaks, I also noticed a stiff brake pedal when starting now that it's replaced. There was pretty much no solution on the boards that was not tried by me. If you have this problem, give it a go and thank me later....lol.

Wow lol. I do notice my brake pedal is very soft when I start the car after it’s been sitting. Hmmmmmmm

[irokwrx]

Originally Posted by kolosy

update here.. swapped out the intake temp sensor (and checked that the wiring wasn't damaged) and threw in new plugs. no effect on cold start.

i've got injectors coming next and have the fuel tank vent valve sitting for when i do all that.

not sure where to look after that..

Read my post, I found the fix.