Electrical

[jj7]

Need some comments regarding the idle of my 525i,94...when i am in full stop like on a traffic light, the idle usually is 700, if i turn the AC on the idle drops to about 600-620, when i turn off the AC, it still stays low, and doesn`t come back to the 700 average unless i riv it up a little bit. some time ago i checked the battery voltage nothing unusual, almost all ground points were checked and cleaned including the baterry polls as well...no headlights flikkeing...
is it electrical or should i be looking to something else????
thnx

[chamilun]

i would recommend greasing the throttle cable.

[Dan in NZ]

The idle is controlled by the idle control valve. It is operated by the Motronic computer, and opens or closes to keep the idle at a certain RPM. The computer only uses the air valve and idle circuit if the throttle position switch is in the closed position. With your engine off, open the hood and move the throttle with your hand, when it gets to the closed position you should hear a "click" from the position switch. (also another click when it's fully open to indicate WOT). If you don't hear a click at the closed position, your throttle cable could be too tight, and may need adjusting.

If you do hear a click, you might need to test the throttle switch and idle air bypass valve to make sure they are working correctly, but start with the simple things first...


PS. IF the M50 has an electronic throttle, I'm lost.

[jj7]

The idle is controlled by the idle control valve. It is operated by the Motronic computer, and opens or closes to keep the idle at a certain RPM. The computer only uses the air valve and idle circuit if the throttle position switch is in the closed position. With your engine off, open the hood and move the throttle with your hand, when it gets to the closed position you should hear a "click" from the position switch. (also another click when it's fully open to indicate WOT). If you don't hear a click at the closed position, your throttle cable could be too tight, and may need adjusting.

If you do hear a click, you might need to test the throttle switch and idle air bypass valve to make sure they are working correctly, but start with the simple things first...


PS. IF the M50 has an electronic throttle, I'm lost.
I just did try hearing the ticking test, didn`t manage to hear a thing,maybe it requires doing again...i suspect the cable though, one time i had it tightend but still can feel it bit loose,idoubt if my car has an electronic throttle,i think that applies for the M3`s if not mistaken.Since you mentioned the switch, is it possible that it is faulty and the Modic3 can`t detict it??? i read lots of comments where the modic does not give any fault for a certain sensor or switch, and when replaced the car goes fine (Myths and Realities)...

[Dan in NZ]

"Since you mentioned the switch, is it possible that it is faulty and the Modic3 can`t detict it???"

Yeah, that's possible... Here's the bit where someone else says how to loosen the cable so the switch can engage, or repair the switch...

[632 Regal]

My cable has an adjustment spot at the end of the cable shield, kinda like a minibike or lawnmower deal. Loosen it up to the point you KNOW it's loose then listen for the click sound.

[ryan roopnarine]

....u sure that the issue you describe is even a problem? the ac compressor will do all kinds of weird stuff if it isn't perfectly content. i'm down a lb of r12 and i get the same result, it corrects itself after a little while.

[jj7]

....u sure that the issue you describe is even a problem? the ac compressor will do all kinds of weird stuff if it isn't perfectly content. i'm down a lb of r12 and i get the same result, it corrects itself after a little while.
Dan it is interesting to know that faulty switches can`t be detected if faulty, but does that apply to major sensors like O2??or a knock sensor??? as for the adjuster Jeff i got the same on my car like yours,and i did tighten it some time ago, i`ll try to loosen it and see the difference...other than the AC, if i turn on the headlights or press the electrical window to go up or down, the same symptom happens,what i meant Ryan is that i felt like a power drain in the system,its normal that this happens when the AC is turned ON... i would suspect the Idle Valve, but i found this idle thing is more likely to show up when any electrical component is turned ON.Furthermore, i tested the electricity fluctuation, the Ohmeter gives 14.2 V when car is idling,when i turn on the AC,it drops to 13,2 V and stays there,thats when i wanted to check the alternator as it compensates for the loss of voltage..
any thoughts guys?
Tnx

[jj7]

Dan it is interesting to know that faulty switches can`t be detected if faulty, but does that apply to major sensors like O2??or a knock sensor??? as for the adjuster Jeff i got the same on my car like yours,and i did tighten it some time ago, i`ll try to loosen it and see the difference...other than the AC, if i turn on the headlights or press the electrical window to go up or down, the same symptom happens,what i meant Ryan is that i felt like a power drain in the system,its normal that this happens when the AC is turned ON... i would suspect the Idle Valve, but i found this idle thing is more likely to show up when any electrical component is turned ON.Furthermore, i tested the electricity fluctuation, the Ohmeter gives 14.2 V when car is idling,when i turn on the AC,it drops to 13,2 V and stays there,thats when i wanted to check the alternator as it compensates for the loss of voltage..
any thoughts guys?
Tnx
Hay guys, i just loosend the throttle cable a little bit, the idle went further down....is it better to have it adjusted by a pro? or shall i try again??

[632 Regal]

Hay guys, i just loosend the throttle cable a little bit, the idle went further down....is it better to have it adjusted by a pro? or shall i try again??

[jj7]

Jeff, i did a test drive with car,noticed lots of hesitation.after that turned of the car,when turned the engine on again the RPM indicator went up to 3k and stayed there but engine was stable :( , i turned the engine off and did the CHECK CONTROL TEST the RPM indicator came back to normal,strange??
what do you think