[SOLVED] Need help please! Random no start!

Which sensor was replaced?

 

The only thing I forgot to mention in the original post and this whole time, I cleaned the air filter as well. It’s a full Cobb filter set up so I followed their site on cleaning it with their kit (‘soap’ and oil) but it won’t start even without it on.

 

Cam position sensor, the one that sits on top the valve cover.

 

You mentioned it catches sometimes when you're trying to start the car...do you mean it occasionally fires every once in a while?

If not, do you smell any unburned fuel out of the exhaust or cylinders when you pull the plugs? I'm curious if you're getting fuel to the combustion chamber.

 

Yes, occasionally it will catch for a split second but nothing happens. And their is a fuel smell from the engine bay. Not sure about from the exhaust. It’s just me trying to do this alone so it’s hard to catch everything

 

Also tried to choke the car and start it, (block the intake from pulling air to get fuel to flow better) that got me a more consistent attempt on starting. (Every turn over was catching but only for a split second but lead to nothing again) I checked the plugs after doing this to make sure I didn’t flood out the motor. Clean.

 

Yeah, blowing you guys mind too huh. I get off work at 11pm est, I’ll head back to my garage and sand down the sensor place again, hook up the battery charger to make absolutely sure that it has charge, add gas in the tank to be sure it has gas and make another attempt at starting. I’ll grab pictures to give you guys some help. Thank you all.

 

Also check that you didnt leave your VTCS unplugged, which may be why you're having better luck with starting by choking the air intake.

EDIT: I agree...i was definitely grasping at straws with this one.

Since you're smelling fuel under the hood, maybe make sure you didnt unclip or damage one of the fuel lines to the HPFP when you were wrestling the valve cover in / out of place.

 

VCTS won't cause that. Lots of us don't even have VCTS.

As for OP it would be helpful if you could get some logs or something; does the tach move when you try to start?

 

VTCS is all good, checked that last night. Haven’t got around to doing the delete on it. And I traces all the fuel lines both HP and LP to be sure all was good and they are.

 

The tach does move on start up attempts. Basically the car acts like it wants to start really bad but just won’t. If I had an accessport I would be glad to upload logs or anything helpful but I haven’t got around to ordering the port. And I don’t have a computer for logs either. Which would make all this a lot easier to diagnose. I own a few BMWs and I tell you, I’d rather troubleshoot them than this speed3 any day at this point lol.

 

Sorry I'm not much help here; I wish you luck. Having owned one BMW before, I can sense the amount of frustration you're having with those strong words, lol.

The only other things I can think of:

1) HPFP issue(s)
2) Possibly an aftermarket car starter or immobilizer device malfunction that is cutting fuel. Maybe OEM anti-theft? I don't know.

I really do wish you luck with this one.

 

Pics would def help I am sure it is something dumb simple.

 

Sanded down the cam sensor port to bare metal. No change

 

I FIGURED IT OUT BOYS!! After 4 days, many hours and a lot of words. The cam sensor, for what ever reason, did not seat fully after the many times of it going in and out for test starts. I put the new sensor in and noticed there was a little gap, and by little, I mean micro. So out with the new in with the old and made sure no gap was found and boom. Fired right up. Thank you all for the help and support!

 

Good, glad that you found it!!

 

So glad you figured it out!!!

Was it an aftermarket or OEM cam sensor? May help a guy or gal out in the future to avoid the particular brand you bought.

 

It

The new sensor was from advance auto. They look identical but the o-ring is just barely too big for the hole. Very very hard to catch. I just happen to notice it. I don’t know the brand off hand but if you go to change it, just make sure it’s fully seated and you’ll be fine! Thank you everyone for all the advice and tips. I learned a lot.

 

@JohnnyTightlips gets a cookie for being first to post the correct answer