E34 540 - not starting (no crank) when warm

[clutchplate]

Well, I have this damn strange problem... maybe someone knows about what the problem could be..

E34 540i... 94 model... once I've driven the car around for a while and switch it off, It doesn't wanna start again, it doesn't even crank... if I bridge pin 11 and 14 on the diagnostic port which is ussually used for remote start, the kitty starts right up....

could this be wiring issue ? which I doubt...
the only thing thats been pointed out so far, is Uber Soldat says he has a fanbox under his dashboard which cools his E-Box .. where the ECU is housed under the hood... that fan box in my E34 is missing. So maybe the ECU is getting too warm and it doesn't allow the ignition to start the car ?

Does anyone else know if it could be something else ?

 

[zaleonardz]

Clutcy... clearly its not the starter or solenoid based on the wire trick, and I dont think its the ECU either (based on the wire trick, as that info goes straight back to the ECU) but perhaps it could be a thermal cutoff, its possible,

could be the immobilizer as well, bring it past, and I'll read the codes for you, we can bypass the immobilizer as well I think.

LZ

 

[SirSparky]

have you tried checking your maf sensors?cps sensors?maybe its your fuel pump,once it gets hot it shuts off to protect the engine,thermal protection?

 

[clutchplate]

LZ, could be, as far as I know they have removed the EWS/all security from this car except central locking.. I have new ews modules and ingition and doorlocks for it tho. allready installed the doorlocks, just trying to figure out the ignition wiring, its all fooked.

Sparky, swopped the maf, but for another reason, even if it was those sensors, it would still crank, but it doesn't even crank...

its a damn tricky one this.

---

that said, It could still be a low voltage problem, I'm going to have the alternator and battery tested justnow, just getting the exhaust ... uhm, well, modified quickly... hehe.

 

[BimmerMan]

If bridging the pins on the diag port fires her up, then it is nothing to do with sensors.

Have a look at the ignition switch...it may have dirty of pitted contacts. This is a common problem on the E39 and E38 and I had a similar problem on my E30 until I changed it...

 

[clutchplate]

ok, I found the problem... it was a low voltage problem... The alternator is running at 12.6 volts, so I keep charging my battery on the battery charger, and when the car runs it just drains the battery the whole time... the alternator should be running above 13.5 and between 14 and 16 normally .... SO either I need to replace the regulator on the alternator, I doubt its the rectifier...

or I need a second hand e34 540 alternator... If anyone has any idea where I can get one ? please let me know...
other than this, the car is coming allong very well, the new exhaust is sounding good

 

[zaleonardz]

I must say I am damm impressed with the progress that you have made on this car, its starting to come together really nicely.

Me and the wife will pop around your place over on saturday and plug in the PC to see whats up, my daughter is being kidnapped by her aunt this weekend, so I am heading out to PTA anyway

LZ

 

[clutchplate]

Cool Beans LZ sounds good !

yea, its coming allong well, It frustrates me when things are not like they are supposed to be, so I tend to just jump right in and get things done. hehe.

will be nice to see y'll on saterday I'll invite Uber over, I know he's been waiting to meet you ...

will be super interested to see what errors this thing pops out and then we can clear my airbag light also. woohoo, hehe.

 

[freerider]

oh clutchy, the e34's are famous for throwing an airbag error when the slip-ring behind the steering wheel gets a bit worn.

 

[clutchplate]

ah cool ! thanks for that info Freerider hehe, will check it out, I heard some funny squak with the steering this morning, but disapeared again, was maybe the cold ... will have a looksee