BMW E39 turns off suddnly

[malhilo]

Good morning all...
my car is 525i 2002
recently, somtimes, when the car is turned on, and when I want to start moving, once I my leg hit the fuel pedal, the rpm meter goes up and suddenly goes down until it is off..and when I turn the key off and on again to restart it it will goes on from 3ed or 4th try..
I also noticed that the same thing happens sometimes when it is parked and turn the AC on..once it starts, the car goes off..this also happened 2 or 3 times only..

this happens rarly..
I think it is the spark plugs! which I need to change anyway! but is there anything else that might cause such thing? :hmm:

Thanks guys..

[ahmad.alkhalil]

I used to have a problem with my old e46 but the car never actually switched off... the rpm dropped severly and car shook but never went completely off.

I think it might be the spark plugs. Best option... take it to Dr. Shak :)

[Bashar M.]

i would definitly change the plugs if they are due, but regarding ur problem it might be your MAF sensor or you Ideal Control Valve or related to fuel supply (pump)....check with Falkons garage (in Rashidiah).

[M5drift]

i say air mass sensor.

[superbosy]

hi man i add exactly the same problem with my second car Jeep cherokee, and it was just the fuel pump to change.. ;)

[malhilo]

well..
it is definitely not the plugs, I changed it but the problem still..
what I noticed during those 2 days, is that when the car is cold "for example in the morning" I go without any problems even if I drove for a very long distance, but if for any reason the car turned off, then the problem will appear, it will not start in a right way, and whenever I stop in traffic jam or traffic light, once I hit the fuel it will go off :(

sound strange I know..
are there any suggestions for a garage in Sharjah, as I live and work in it!

[mahmoud_bedewi]

my shoot is the pump has a weak non return valve, this symptom is called "difficult starting when hot" and it is well known with fuel injection systems, when the car is cold fuel is liquid and everything is good but when the car is hot (ie it was shut down after working) the non return valve should maintain the pressure in the system but if the valve is bad, pressure drops and with high temp the fuel evaporates and cause "vapor lock" so u keep trying to start until the vapor lock is discharged then liquid fluid is delivered and the car starts
check fuel pressure after shutting down and if it is low then it is the non return valve

[malhilo]

my shoot is the pump has a weak non return valve, this symptom is called "difficult starting when hot" and it is well known with fuel injection systems, when the car is cold fuel is liquid and everything is good but when the car is hot (ie it was shut down after working) the non return valve should maintain the pressure in the system but if the valve is bad, pressure drops and with high temp the fuel evaporates and cause "vapor lock" so u keep trying to start until the vapor lock is discharged then liquid fluid is delivered and the car starts
check fuel pressure after shutting down and if it is low then it is the non return valve

inta betzaker mn warana? :reading:

sounds reasonable to me.. :thanks2: bro

[ahmad.alkhalil]

Maher please stick to speaking in English as there are members who do not understand Arabic

[malhilo]

Maher please stick to speaking in English as there are members who do not understand Arabic

Ok boss
:iagree:

[M5drift]

i agree with mahmood, i recently changed the pressure fuel valve.

[P3RPL3XITY]

It's the MAF - happened with me.
In most cases, your car won't start if there was a fault with the fuel pump.