Trottle cable issues???

[Zchild]

The saga continues with older vehicles we love... I was on my way home yesterday and about a half miles from the job the car died... I attempted to restart it but it cranks but will not turn over and the gas petal has zero tension so my thoughts are that the throttle cable between the gas petal and the throttle body snapped or somehow became disconnected, please correct me if I'm barking up the wrong tree on this issue. No CEL's, no electric issues just won't crank over so it's in the shop awaiting repair.

[JimLev]

If it cranks it is turning over.
So it just won't START.
A '99 540 should have a tu engine which is a drive by wire setup, no throttle cable.

[geargrinder]

Oh so much to work with.


gas petal has zero tension

Gas petal?
Have you checked the gas stamen?
Are the gas leaves and gas stems healthy looking?
Have you tried some Miracle Gro?


it cranks

won't crank over

It cranks but it doesn't crank!? Sounds like a crank-yanker to me! This whole conversation is making me cranky!

:redspot


No CEL's, no electric issues just won't crank over so it's in the shop awaiting repair.

OK OK enough nut bustage. Srzly:

As Jim says, you got yourself a 'drive by wire' car there.

To confirm and expand on what he's said...



Crank = turning over = engine spins. Neither the terms 'crank' nor 'turn over' have anything to do with cylinders firing. "No-start" or "no-fire" are an entirely different thing than "no-crank" and "no-turn-over". We are going with 'crank but no start' since that's how you started out describing it before you then said all kind of random words that didn't make sense.
Nope, there's no cable.
For the '99 you do have a 'top hung' throttle pedal, so if the feel of the pedal actually changed then you could look around and see if something has come undone up there (later cars have a self-contained pedal mounted on the floor...) But I'm suspecting really nothing has changed because..
Even if the throttle pedal got disconnected the engine should and will start up and idle just fine. Now if the electrical connector came off the DBW assembly or something then it might not start but then you'd prob get a CEL right away, or perhaps a "FAILSAFE" warning.
Don't be fooled that "no CEL means no error codes". There might be codes. For sure reading codes is important first step.
There also might not be codes. Crank-but-no-start with no-codes most commonly on these engines is fuel pump or crank sensor failure. Also possibly - but less likely with no other weird symptoms - could be ignition switch.


Have the shop read the codes...

[Zchild]

So you're saying that a defective ignition switch would possibly allow it to crank, turn-over and not start... Also would an ignition failure cause the vehicle to shut-off?

[JimLev]

Oh so much to work with.



Gas petal?
Have you checked the gas stamen?
Are the gas leaves and gas stems healthy looking?
Have you tried some Miracle Gro?



Good one GG, I missed that.

- - - Updated - - -


So you're saying that a defective ignition switch would possibly allow it to crank, turn-over and not start... Also would an ignition failure cause the vehicle to shut-off?

Yes and yes, but it could be something else too.

[Zchild]

Gotcha; I knew the ignition was beginning to go, because on two occasions I attempted to start the car and got a buzzing sound and on the second attempt it started right up... Yesterday I expected it to give me the buzzing sound on the first start attempt however it started right up and ran about two miles and died and would not restart...

[Zchild]

UPDATE: I was talking to the mechanic yesterday and there's no fuel getting to the fuel rail and the fuel pump isn't priming when the key is turned. Therefore it's narrowed to either the fuel pump or the fuse to the fuel pump. My bimmer should be back on the block sooner than later...

[JimLev]

There are 2 fuses and a relay in the fuel pump circuit.
When you first turn the key to position 2 (not Start) the pump will run for 2-3 seconds and then shut off.
When the key is turned to the crank position the pump will again start.
You can jump the relay contacts to see if the pump will run.
The DME controls the relay coil. If you've got EWS or key issues the pump won't start.

[geargrinder]

Back on the block?! You’re going to sell it just because the fuel pump failed!?

Should be pretty simple to diagnose. Jim’s given all the details. Unlikely to be Vicky failure in this case because it died while running. But maybe. Definitely check relay and fuel pump first. I think we called out fuel pump as one of the top suspects from the very start.

[Zchild]

It's definitely the fuel pump, so we're replacing both the pump and the fuses since the car is 19 years old and the pump has never been changed... Now the other issue which I experienced makes sense when the vehicle shut-off and was difficult to start without a lot of pumping the pedal... The fuel pump was trying to tell me it was on its way out... lol

[alexthebmwguy]

I don't believe E39's have throttle cables like the m52. The m54 uses electronic throttle control i thought?

[geargrinder]

Always good to replace fuses when they get worn out.

Alex - yes the M54 (525/530) is "full DBW"... for the V8, like ZackSr has, the non-VANOS M62 (pre-99) is cable throttle, but 99+ is full DBW too.

ZackSr - pumping the pedal on the DBW in fact doesn't do anything to help the start - there's no accelerator pump or anything. During the moments of startup-crank before the engine is running the computer has total control over the throttle plate, so pumping the pedal wasn't really doing anything but otherwise you're exactly correct, it was indeed probably bad fuel pressure not supplying enough gas for the computerized startup-enrichment to work as its intended.