PDA

View Full Version : Off Idle stumble


python1
07-19-2006, 06:41 PM
Hi all I am trying to sort out a off Idle stumble on my 1994 525I M50 engine, Auto Trans. I have replaced coils , spark plugs, Oxy sensor, throttle position sensor, and intake temp sensor. up acceleration from a stop the engine stumbles and then it catches and takes off. any ideas on where to look from here?

Thanks pan
BillionPa
07-19-2006, 10:28 PM
i can also see from a year ago you got new injectors, did the stumbling start occuring recently?
genphreak
07-20-2006, 02:39 AM
i can also see from a year ago you got new injectors, did the stumbling start occuring recently?Perhaps the fabled 19lb injectors? I bet they are not the stock ones... and you do not have one of Mark D's chips right?
Ausmpower
07-20-2006, 09:35 AM
Air flow meter?

Throttle position switch?
t_marat
07-20-2006, 12:47 PM
By stumbling you mean the engines starts coughing or it just hesitates?
If just a hesitation, then it might be MAF.
python1
07-25-2006, 07:49 PM
No it has not it's been there the whole time. The injectors and Coils were my first attempt at solving the stumble.
python1
07-25-2006, 07:51 PM
It is just a hesitation
python1
07-25-2006, 07:52 PM
Just replaced the throttle position switch, intake air temp sensor, and the oxy sensor. new injectors and coils a year ago.
python1
07-25-2006, 07:53 PM
The injectors are stock rebuilt ones from http://www.fiveomotorsport.com
genphreak
07-26-2006, 12:33 AM
The injectors are stock rebuilt ones from http://www.fiveomotorsport.comReally? Did you confirm they sent you the BMW part... not the FOTE-D5B or other generic 'replacement' types? Five-O are the major source for those... part number is on the side of each injector; at the top. You sure the TPS switch is properly adjusted too; according to Bill Rs posts showing the correct BMW procedure from the TIS? Next step is to test the AFM output as you push the air flap open- is ti reading a consistent increase in resistance as you open the flap? This is a common cause of bad DME data. :) Nick
python1
07-26-2006, 04:06 PM
Yes they are the correct injector parts even the same stk color (light green), I installed a new TPS and I will test the restance during opening the throttle, I did not see Bill Rs post. Do you have the link?

Thanks
genphreak
07-26-2006, 06:51 PM
Yes they are the correct injector parts even the same stk color (light green), I installed a new TPS and I will test the restance during opening the throttle, I did not see Bill Rs post. Do you have the link? ThanksCould also be the AFM since your TPS has been replaced, but check is necessary of both. I don't have Bill Rs post from the TIS, but that could have been M30 specific I can't remember.

Maybe someone can fire up the TIS for you and post the procdeure? Ijust don't have it handy I'm afraid...