Two years of intermittent hard starts, please help!

[ATB88]

Has anyone here tried replacing the oring on the driver side fuel transfer tube? I was having hard start issues, idle issues, loss of power and the car would outright die sometimes. My friend pointed out that the o-ring was expanding and causing a "leak." Well I replaced it today and no more hard starts or issues. Just a thought.

Very interesting. That fuel transfer tube is pretty much the only component of the fuel system that I haven't touched at this point (aside from the fuel lines themselves). I had wondered if it was worth looking into, and it would seem the answer is yes! Do you have a p/n for the o-ring, and how accessible is it??

[sapote]

Thanks Terra.

My only experience is on the ms43 EWS. On that one we just jumped two of the heavy gauge wires together and disabled ews in the ECU. Been rock solid for months now.

I suspected the M3 EWS was more complicated but didn’t find any good wiring diagrams.

Any refs you can share?

If the EWS is bypassed and the connector pin1 and pin2 jumped together, sure it works as you said but the ignition switch will die soon. The EWS internal "relay" is to reduce the current load on the ignition contacts.

[sapote]

81k mile car, have had it since 45k miles. For the first year it had always fired up beautifully with no hesitation or stumble. Two cranks then on, to a rock steady idle, every time.

I read this thread for the first time today; don't know why I missed it.
"two cranks then on (engine fired up?) as you expect for a normal engine before you experienced with hard start? Why two cranks is normal?

In the first video, what are those two chirping noises at 0:03 , 0:04 timer, 0:26, 0:36, and 0:37 timer? Are these moments your starting problem that the engine didn't crank?

At 1:31 to 1:32, it seems the engine fired up but the starter gear was not released from the flywheel. Did you release the key too late?

I'm not sure that your concern is about those chirps or the issue at 1:31 to 1:32. If the issue is at 1:31 then I to test by pushing and jump clutch in 2nd or 3rd gear.

[eacmen]

If the EWS is bypassed and the connector pin1 and pin2 jumped together, sure it works as you said but the ignition switch will die soon. The EWS internal "relay" is to reduce the current load on the ignition contacts.

If the EWS internal relay shorts pin 1 & 2 when the key is present how would directly connecting them be any different than a normal start condition?

We put an inline fuse between the wires just to be safe. But if the two contacts are shorted by the relay during a normal start condition what is the harm of keeping them shorted?

I understand that normally you might want a relay in there for clutch switch or other safety conditions before allowing the starter to run. That’s the only reason I can see relay be necessary.

You’re usually right sapote so I’m probably missing something obvious.

[ATB88]

Hi sapote ! Thanks for taking a look

"two cranks then on (engine fired up?) as you expect for a normal engine before you experienced with hard start? Why two cranks is normal?

I'm just saying that this was my experience with the car before this trouble started. Was extremely consistent in its start behavior.

In the first video, what are those two chirping noises at 0:03 , 0:04 timer, 0:26, 0:36, and 0:37 timer? Are these moments your starting problem that the engine didn't crank?

At 1:31 to 1:32, it seems the engine fired up but the starter gear was not released from the flywheel. Did you release the key too late?

I'm not sure that your concern is about those chirps or the issue at 1:31 to 1:32. If the issue is at 1:31 then I to test by pushing and jump clutch in 2nd or 3rd gear.

I'm not sure exactly which chirping noises you're referring to in the first video (this one https://www.youtube.com/watch?v=wwTBwz5oHU4)? I don't hear chirping at the timestamps you've indicated. I hear one distinct chirping noise at 0:07. This is uncorrelated from any hard start behaviour I've experienced, and I believe is coming from somewhere in my convertible top system (perhaps the pump)? In the first video, my concern is the slight stumble in starting at 1:30. I don't think I'm releasing the key too late -- I release the key when the engine has stopped stumbling and it's clear it will start. If I release earlier than that, it won't.

In the second video, we have several struggling starts in a row, starting with the first: https://www.youtube.com/watch?v=ZRlEFfOa_r4

I must admit the starts in these videos (taken more than a year ago) don't seem as bad as it is now. It struggles harder now, and, again, occasionally, it just doesn't start at all. I think maybe I should try and get some more recent hard starts on film to give an idea of what things are looking/sounding like now. I'll try and do that over the next week or so.

If the issue is at 1:31 then I to test by pushing and jump clutch in 2nd or 3rd gear.

What exactly do you mean here? You mean get the car rolling with the engine off and do a rolling start in 2nd or 3rd gear? I'm wondering what your trying to test here? Some problem with first gear? Since the problem is intermittent, it could be difficult to conclusively test if we can get a hard start from a rolling start or not.

Thanks for the insights!

[jet_dogg]

I HAVE NOW BEEN CHASING THIS PROBLEM FOR NEARLY TWO WHOLE YEARS :'<

Here's a current theory (a total reach, but a theory nonetheless): this all started after I did some VANOS/re-timing work (and yes, VANOS pass test with flying colours). Could be a coincidence, could be related. One possibility: I somehow manhandled the cam impulse sending wheel (at the back of the cam that give magnetic signals to the cam sensors) and warped a finger or something, and when that finger is in a certain position at startup it causes weird behaviour? Again, a total reach, but seriously, what else could it be at this point??

Are you imagining damaging the impulse wheel or do you think you actually did?

[jbfrancis3]

I don't see how you pass a VANOS test with flying colors with a stock CSL software (and CSL cam offsets) but with factory cams. Have you ever had it tuned before? Why don't you reach out to PCS Tuning, explain your hardware setup and let him set you up with a tune (no dyno, even). You'll be amazed. Start there, and then evaluate the cold start. If needed, he can modify the cold start table.

[ATB88]

Are you imagining damaging the impulse wheel or do you think you actually did?

Yeah, like, maybe, somehow, I slightly bent one of the fins on one of the wheels, and the reason the issue is intermittent is because it happens whenever that fin is in a certain position relative to the cam sensor at startup, or something?? It's a very specific and very unlikely theory lol. Only reason I mention it is because it seems like I've ruled all of the likely causes out, and this one would be consistent with this issue starting right after I opened my valve cover to re-time the engine and do a valve adjustment. But it also seems unlikely that I could slightly damage on of those wheels in such a way that it would subtly sometimes affect startup, but not how well the car runs afterwards, so, ¯\_(ツ)_/¯ this is how desperate my brain is now.

I don't see how you pass a VANOS test with flying colors with a stock CSL software (and CSL cam offsets) but with factory cams. Have you ever had it tuned before? Why don't you reach out to PCS Tuning, explain your hardware setup and let him set you up with a tune (no dyno, even). You'll be amazed. Start there, and then evaluate the cold start. If needed, he can modify the cold start table.

Good catch, thanks for thinking about it! I should clarify: this hard-start behaviour far pre-dates my installation of a CSL airbox and conversion to modified CSL software (modified to stock cam offsets) on my DME. The hard-start behaviour that I have now is identical to how it was when the car was completely stock, at which time it was passing VANOS test with flying colors. No custom tune, just the most up-to-date stock software on a non-HP DME. Even tried switching to an HP DME with stock software on the off-chance that my DME was the issue. Also, I should clarify that this is not a cold-start issue -- it most often happens on warm starts (but that could just be bias due to the fact that the car only gets cold started once a day but warm started several times a day). So, even if a custom tune could fix this, the underlying issue isn't tune related. FWIW, I'm on the books to have Hassan dyno-tune me after I install my SSV1s, but that has to wait at least a month so I can finish/defend my thesis!

[DropTopKingM3]

My car was plagued with this for years. Im currently having the vanos, rodbearings, cooling system, alternator all done along with new fuel filter, fuel pressure regulator, crankshaft and camshaft position sensors. If the car still fails to start on the first try I will have my injectors sent out for cleaning. The fuel pump was also changed but I will also be addressing the tube mentioned in this thread.

[sapote]

If the EWS internal relay shorts pin 1 & 2 when the key is present how would directly connecting them be any different than a normal start condition?

Sorry I haven't look at this thread until now.
The relay does not short out pin1 and pin2 together. Pin2 is the signal from the ignition switch when turned to START, and when pin2 is 12v, then the internal "relay" connected pin1 to either pin10 or pin11 (system uses 2 pins for redundancy).

One needs to add a relay which is controlled by pin2 to connect pin1 (to starter) to power source pin10 or pin11. If not, the ignition switch contacts for pin2 will be burned and pitted soon.

[sapote]

I'm not sure exactly which chirping noises you're referring to in the first video

Chirping at 0:04, 0:05, 0:27. But as you said these were not related to engine.

What exactly do you mean here? You mean get the car rolling with the engine off and do a rolling start in 2nd or 3rd gear? I'm wondering what your trying to test here? Some problem with first gear? Since the problem is intermittent, it could be difficult to conclusively test if we can get a hard start from a rolling start or not.

Yeah, do a push start or rolling start and this will tell us if the engine will fire up without hesitation as compared to using the starter to crank it. For whatever the reason, if the starter gear doesn't release from the flywheel properly, this might cause the issue you have, and so I suggest to do a push start to see the same result or different.

[eacmen]

Sorry I haven't look at this thread until now.
The relay does not short out pin1 and pin2 together. Pin2 is the signal from the ignition switch when turned to START, and when pin2 is 12v, then the internal "relay" connected pin1 to either pin10 or pin11 (system uses 2 pins for redundancy).

One needs to add a relay which is controlled by pin2 to connect pin1 (to starter) to power source pin10 or pin11. If not, the ignition switch contacts for pin2 will be burned and pitted soon.

Wow BMW really decided to drive the starter with a 12v supply from a smaller gauge wire?

The wire going to the starter is significantly heavier gauge than pins 10 or 11. I suppose if those 12v supplies are properly fused I guess it doesnt matter

Thanks for the info.

[ATB88]

Chirping at 0:04, 0:05, 0:27. But as you said these were not related to engine.


Yeah, do a push start or rolling start and this will tell us if the engine will fire up without hesitation as compared to using the starter to crank it. For whatever the reason, if the starter gear doesn't release from the flywheel properly, this might cause the issue you have, and so I suggest to do a push start to see the same result or different.

I see. I replaced the starter quite recently, but I suppose that doesn't completely rule it out if perhaps there's an electrical issue that would affect how the starter behaves. I actually park on quite a steep hill outside my house in LA, so it would be easy to do some rolling start for a few days. I'll try it and see if I get any hard starts that way.

[mtech9]

Like a lot in this thread, I also had this issue - for 2+ years. Fuel pump died and when I replaced it, it never happened again...

[DropTopKingM3]

Here's a video of my cold startup problem. Ive had this issue for years now. So far I've replaced the fuel pump. I'm currently having the fuel filter, fuel pressure regulator, crank, and camshaft sensors replaced.