Two years of intermittent hard starts, please help!

[Redline]

I thought you replaced everything bumper to bumper ? This is right behind the back bumper 😂

Everything but that, the canister, vapor line and fuel tank itself. Smoke test showed no leaks/issues with those parts and showed they were operating fine when testing so I left it alone.

Maybe I shoulda loaded up the parts cannon once last time 😂

[DropTopKingM3]

This. For science.


plus it’ll save me $140 before I order one myself 😂

I thought you replaced everything bumper to bumper ? This is right behind the back bumper 😂

[DropTopKingM3]

I had read it and understood how the diagnosis works, but don’t see how it affects the starting.

If it were me I will install the “bad” air pump back to prove the problem comes back.

Maybe I’ll give this a try and report back.

[Redline]

I had read it and understood how the diagnosis works, but don’t see how it affects the starting.

If it were me I will install the “bad” air pump back to prove the problem comes back.

This. For science.


plus it’ll save me $140 before I order one myself 😂

[Redline]

I would be checking vacuum lines and the intake system. An air leak can cause a car to run rich.

Stock tune?

Lines are new, seals/orings are new.

[sapote]

sapote read this post in this thread. It’s #65.

I had read it and understood how the diagnosis works, but don’t see how it affects the starting.

If it were me I will install the “bad” air pump back to prove the problem comes back.

[DropTopKingM3]

it will eventually adapt. inpa and many other scan tools can reset it.

you can also try some of the other method that don’t require scan tool:

https://www.e46fanatics.com/threads/...tions.1125131/

Thank you. I’ve been meaning to get my hands on pasoft or inpa. It seems like it’s the best way to get things done.

I think I sorta reset throttle adaptations last Tuesday when I went for a ride in a Mexico and I revived my 20s again haha! 😈


But for real, I want to thank everyone who contributed and suggested. My car is almost near where I want it to be and I’m thankful for that. The cold start gremlin was really annoying me. I did a refresh anyway so I didn’t mind throwing extra parts on it. Heck I even have some more on the way that I’ll install now.

I’ll keep updating this thread as I will begin letting my car sit for a few days here and a few days there to test longevity.

Hopefully someone who has the same problem browses through this thread and it can help them.

[eacmen]

I was wondering if I had to reset adaptations. Is there a way I can do this myself or does it adapt on its own after a certain amount of miles?

it will eventually adapt. inpa and many other scan tools can reset it.

you can also try some of the other method that don’t require scan tool:

https://www.e46fanatics.com/threads/how-to-truly-reset-throttle-adaptations.1125131/

[DropTopKingM3]

Normal for first start after resetting adaptations to be rough. Probably a good idea to change adaptations after installing injectors.

I was wondering if I had to reset adaptations. Is there a way I can do this myself or does it adapt on its own after a certain amount of miles?

[DropTopKingM3]

sapote read this post in this thread. It’s #65.

[DropTopKingM3]

Congrats! Keep this updated if it comes back or went complete away.

I think more the Charcoal canister (if you mean this with „filter“) was the solution in your case, according to E39 m5‘s (source m5 board) where this is often the solution for starting problems.

I read the same thread. I actually have a charcoal canister en route to my house along with the fuel pump relay and some other stuff. I might as well replace them now since they’re already paid for and my entire car is pretty much refreshed. Thanks bro.

[DropTopKingM3]

I think he meant the leak diagnostic air pump and its air filter (don't want to pump dirty air into the system).

i replaced the air pump, the filter, and the grommet that goes onto the air pump. I also threw in a set of temporary injectors at the same time while I sent my original ones out for a cleaning. All is well so far 7/8 days it started on the first crank 🤞

[sapote]

I think more the Charcoal canister (if you mean this with „filter“) was the solution in your case

I think he meant the leak diagnostic air pump and its air filter (don't want to pump dirty air into the system).

[sapote]

Day 8 - started on first crank 💪
the dtml pump did the trick! 🤞

I'm glad you have it fixed.
wonder why a bad DTML pump caused the bad starting? This pump is only used for fuel vapor system leak diagnostic and should not affect the engine operation. I'd like to know the reason.

[eacmen]

Normal for first start after resetting adaptations to be rough. Probably a good idea to change adaptations after installing injectors.