No Start – First attempt when cold

[Ramps]

Has anyone solved this issue? It seems to be fairly common in E46 and E39 forums and it’s been happening to me for the past 2 summers (it’s stored winters).

It started last summer where if the engine is cold (sat overnight or a few days) it doesn’t matter how long I let it crank for, it doesn’t fire. It sometimes sounds like it almost fires but doesn’t and you can crank away for 10-15 seconds and nothing. The second attempt it usually fires right up, sometimes it’s a bit rough for a few seconds.

This past spring I rebuilt the VANOS and cleared adaptations. All went well and no codes. Still does it.

A month later I changed plugs and coils, no change…still does it.

I cleaned my throttle-bodies and AIC valve a month ago. Still does it.

I’ve swapped out to my spare MAF, still does it.

It doesn’t matter how long or how many times I prime the fuel pump...still does it.

There are no codes.

Some people say it’s the fuel pump going but I’ve seen threads where others say it didn’t fix the issue, and my car runs fine once started and the power level seems normal and the plugs I changed a few months ago looked the perfect colour for used plugs.

I am really at a loss…I don’t want to start throwing money at it…could it be the key/EWS system? Could the key battery be low? Funny enough I found an old thread I responded to from 2010 where I was having the same issue intermittently...ultimately I guess I solved it or it went away, this time around no luck.

TIA

[heinzboehmer]

EWS or key would not allow the engine to crank so it's not that.

To me it does sound like a fuel issue. Have you measured fuel pressure? I would measure when the car is running, right after turning off, the next morning when the car is completely cold, and when cranking cold.

[akamin68]

This recent YT video has replacement of full pump not resolving issue.

https://youtu.be/TWt8ZCIaRo0

My 04 e46 M3 exhibits same behavior. Occurs intermittently which makes tracking it down that much more fun.

Sent from my BTV-W09 using Tapatalk

[ethan]

It's either 1.) a bad check valve on the fuel pump or 2.) leaking around the submersible flex tube connecting the pump to the housing. The latter usually happens when moving to an aftermarket pump and reusing the original line. Can get replacement PTFE ones at Radium.

I chased this problem forever with Walbro pumps in 2 M3s. I'm fairly certain this is the reason people tend to return to stock pumps after trying aftermarket ones.