e30m40 engine stalls during idling

[selespeed]

hi;i have had this annoying problem for a few months. but it appears to be getting worse lately. when i cruise to a stop, the engine stalls or idles very badly - rpm goes up and very low down and fluctuates. and eventually would stall. :angry: what is the cause of this? have you guys had this problem and how to overcome it? for your info, i have had new plugs about a month ago but it didn't cure the problem... :angry: advice and solution please.......... :huh:

 

[shaifulo]

i think your ICV is going already...

 

[selespeed]

Originally posted by shaifulo@Jul 19 2005, 10:18 PM
i think your ICV is going already...

idling valve? can it be serviced or cleaned? how much is a new one?

 

[koryong]

if your idle is fine during normal circumstances ie. start-up etc, and this problem only happens after slowing down from a cruise, then it's most likely the air flow meter (AFM).

Happened to my car recently. The flap in the AFM gets stuck against the internal walls due to distortion after many years of heat etc. Good news is this can be serviced for very little money as compared to changing a new AFM ....

 

[selespeed]

Originally posted by koryong@Jul 19 2005, 11:17 PM
if your idle is fine during normal circumstances ie. start-up etc, and this problem only happens after slowing down from a cruise, then it's most likely the air flow meter (AFM).

Happened to my car recently. The flap in the AFM gets stuck against the internal walls due to distortion after many years of heat etc. Good news is this can be serviced for very little money as compared to changing a new AFM ....

hi koryong;

thanks for your input. it is not due to AFM because i have it swapped with another car and his car idles well with my AFM.

i also have difficulty maitaining my idle this morning during cold start. probably one of the ICV or throttle valve body? is it easy to take out? which one should i try first you reckon?

 

[iCe]

happened to me also last month.send it to workshop,the mech said need to tune back ,the fuel la and air intake lar(i dun really understand what he said) but,its ok now.,hihi

 

[Zoggee]

there must be some error reading(fault codes) in ur DME...go check!!

My car idles like washing machine la...

 

[fabianyee]

check for air leaks too on the air boot connecting the AFM to the throttle body... There might cracks in between the folds.

 

[Zoggee]

Originally posted by fabianyee@Jul 20 2005, 02:47 AM
check for air leaks too on the air boot connecting the AFM to the throttle body... There might cracks in between the folds.

yeah hor...I had that problems before ..why didn't I think of that

 

[Fuhrer]

Originally posted by Zoggee@Jul 19 2005, 11:59 AM

My car idles like washing machine la...

you running hotter cams that why lah..

 

[Zoggee]

Originally posted by Fuhrer+Jul 20 2005, 02:52 AM-->QUOTE (Fuhrer @ Jul 20 2005, 02:52 AM)

 

[teejay]

older e30 had air slide valve instead of the ICV

ASV is located just below the throttle body, and check all rubber boots for leaks, normally a small hole and whack your idle way off, better stil some times your idle is ok, hole is small, idle bad, the hole tends to be bigger

 

[shaifulo]

so selespeed,

yours the m10 or m40?

 

[selespeed]

Originally posted by shaifulo@Jul 20 2005, 11:08 AM
so selespeed,

yours the m10 or m40?

m40

 

[535i]

Eventhough u have swapped ur AFM, try this ..

When the idle is erratic, pop the hood and knock the AFM (not so hard laa) with ur fist. If ur idle is normal, it's the AFM.

DME will read ur previous AFM reading - even when u swapped ur AFM. Need to reset the fault before installing the new AFM ..

That's what I did to my M40 ...

 

[rezzy3181]

Well this is my experience with my M40 engine:-

My AFM gave problem years back and with nuts MACH guessing work I ended up spending thousands till most in my engine compartment are new till the exhaust centre box was change too.

Change my wiring plugs cable, coil, something under the trottle cable,(apa nama tak tau sorry) distributor set, and some other electrical cables that I am not familiar with. all change new no second hand.
My problem as I speed along the Highway daily KL-Sban I run normal say 110 then try to overtake the car refuse to go sangkut2, Cuntcil makan like nothing malu lah. Went to a few socall sifus with diffrerent answers one even service my AFM but young boys same age as my son still makes no different, suffered can say few years till about a year and a half back can'nt stand any longer bought a brand new AFM change it then thats the fault if you speed and the car malu to speed make alot of difference. After knowing BMW Club sifus then came to know that the AFM is serviceble, never mind got new no regrets, sayang left mine at the w/shop.

Another experience after a new AFM fix, got to be careful when taking out the rubber bellow from the trottle area to the AFM, very sensitif if you have a tiny hole your car will jurk at low speed or crawling Q. Had that happen after I fix mine, went to the w/shop they also can'nt trace it (with computer checking also can'nt trace (got to see the boys work) chincai2 rough habis lah our car) I trace it myself at last when I was doing something to my engine compartment, I open my air filter saw the crecks, seal it with 2ton glue the car run smooth yet I go back to the w/shop and teach them to be careful when dealing witn that. they say yah kah.

My habit is the engine must be always clean then any fault you can see clear and w/shop ada malu sikit buat kotor to our engine.

Well that is my tips that I have gone through if yours clicks check out the 2 types of my experience. (Sorry I am not technically expert as Fabianyee, Kevter, 535i and others) but I will let others know what I have gone through and learn the mistakes. best of luck and I still love my M40 & keep it even I go for another Bimmer later.

 

[MeanStreak]

Originally posted by rezzy3181@Jul 20 2005, 05:13 PM
something under the trottle cable,(apa nama tak tau sorry)

TPS kah?

 

[rezzy3181]

Originally posted by MTek1318+Jul 20 2005, 05:18 PM-->QUOTE (MTek1318 @ Jul 20 2005, 05:18 PM)

 

[MeanStreak]

Originally posted by rezzy3181+Jul 20 2005, 05:23 PM-->QUOTE (rezzy3181 @ Jul 20 2005, 05:23 PM)

Originally posted by MTek1318@Jul 20 2005, 05:18 PM

 

[rezzy3181]

Thats right Mtek.