540i cranks one revolution and stops. Will not start

1998 540i M62 non vanos engine

I just finished replacing the clutch and now the car wont start. It will crank for what sounds about 1 revolution and cut out and continue.When it cuts out the steering wheel will go up and down as if the ignition switch is shut off and on. The thing that puzzles me the most is that it will crank normally if I unplug the crank sensor.

Here are the things I have verified:

-Checked the ohms of my brand new oem crank sensor. (624)
-Double checked all of the teeth on the reluctor wheel on my jb race flywheel through the sensor hole.
-Checked for spark and have it when it eventually gets to my cylinder with the tester on it.
-Checked for fuel pump activation and have it.
-Checked for codes in generic with my snap-on ethos. None present.
-The scan tool shows no RPM in generic but it is slow in that mode.

I was experiencing a whole bunch of random electrical problems before I removed the trans but the car always started. I would intermittently not have any dash indicators for the turns and high beams. I had an abs and traction light on and my cruise stopped working.

What the hell is going on here? All I did was change a clutch and it somehow resulted in a no start condition. This car really pisses me off...

Any advice would be greatly appreciated.

do you mean m62?

it sounds like your have a bad igition switch.

read this:

http://forums.bimmerforums.com/forum....php?t=1205148

and

http://forums.bimmerforums.com/forum....php?t=1539722

Originally Posted by Topaz540i

do you mean m62?

it sounds like your have a bad igition switch.

read this:

http://forums.bimmerforums.com/forum....php?t=1205148

and

http://forums.bimmerforums.com/forum....php?t=1539722

Has an failed ignition switch resulted in a no start condition for anyone in this way? Why will it crank continuously when the crank sensor is unplugged?

I'm going to take out the switch right now, ill post back my finding later.

this switch looks like it has been replaced. It looks brand new and has a black plastic housing. has anyone devised a way to test the ignition switch?

This makes absolutely no sense. The car will crank and crank and crank when the crank sensor is plugged in (no spark and fuel obviously),but when its plugged in it will only crank till a certain spot and stop. When this happens the head lights turn on the the gauges go nuts. What the hell is this? The only reason I took this stupid thing apart again is because clutchnet sold me a disk at the incorrect thickness. I just don't get it. The key battery seems to be dead, would this have something to do with it? I see on the mitchell wire diagram there is a module called the electronic drive-away protection control unit. Could this be interrupting the starter for some reason? I am at a total loss and really could use some help. Searching has got me nowhere.

I see absolutely no reason why this car will not start...

bump

Amazing, 126 views and no valuable incite has been provided... no one can help me?

Originally Posted by neonphire8604

Amazing, 126 views and no valuable incite has been provided... no one can help me?

Probably a good time to break down and have a pro look at it.

Originally Posted by AnotherGeezer

Probably a good time to break down and have a pro look at it.

Apparently none exist on this forum. Should have known this was a waste of time.

Originally Posted by neonphire8604

Apparently none exist on this forum. Should have known this was a waste of time.

That attitude is going to get you lots of support.

As much as I understand your frustration with this problem, expecting professional troubleshooters to flock to your aid is a little unrealistic. Be patient, I'm sure one of our excellent BMW savvy technicians will see this topic and offer some suggestions.

above post is definately the right way to get people's attention...

I'm sure they're lining up for you now.

Sounds like a weak battery to me.

BMW's are hypersensitive to voltage.

I just bought a jump pack yesterday. It's almost done with its initial charge so I'm going to try it after the jets game. You could be on to something here. This was an okay battery during the summer months but I did deep cycle charge it like 5 times to get it to hold a charge.

Hope it works out for you. There is nothing more frustrating than doing some major mechanical work and then having a glitch like this prevent you from enjoying the fruits of your labor.

i'd imagine if the key battery was at fault your alarm would go off as well during start-up?

Your telling me. Maybe the cold nights killed this battery once and for all. This is the third clutch I had to put In this thing. It turns out jb race sold me a flywheel that was out of spec. Clutchnet had to build a custom thickness disk for it to work properly.

BMW's exhibit all kinds of weird behavior when the voltage sinks below a certain level for sure.

Originally Posted by Reuvers

i'd imagine if the key battery was at fault your alarm would go off as well during start-up?

I unplugged that annoying pos a wile ago haha. It isn't going off though

Advance has one in stock I'm going to go buy it. Wish me luck. What's the saying? KISS. Maybe I'm over-thinking it.

I wish you good luck.

Sometimes it really does come down to the simple stuff.

I guess I can check bad battery off my list. Here is a YouTube video of what it's doing.

Pleanty of fuel and spark. It's burning the crap out of my eyes still... You can here it cough once and a while too.

Have you measured the spacing between the Crankshaft sensor and a pulse tooth? It s/b 0.55 +/- 0.2 mm.

If the gap is too large, it may explain the symptom. Since you have replaced the flywheel, this could be the problem.


Reuvers,

Tye key battery has nothing to do with starting the engine; it's just for remote entry.

I tried my best to measure it with my vernier caliper. The back part extends as you run the clamp in and out measure depth but it is not wide enough to sit nicely on both sides of the hole...Should I try plastic gauge?