car timing going up and down

[koaygk]

do anyone come across car timing going up and down ( rpm between 0.5 - 2 ) when engine is cold and sometime even after driving for 1/2 hour in traffic jam? When engine is cold, i have to switch on the aircon then only it will stable at rpm 1, otherwise it will just go up and down until aircon is on.

 

[Hammer278]

Hello there,

Yeah I have that issue...though when I first start my car it's stable at 0.8. However, there are certain times when I'm stuck at a traffic light and when I shift to Neutral the rpm starts to fluctuate between 0.8-1.2rpm, almost sounds like I'm revving the car getting ready to race.

Trust this is a very minor fuel feed issue. It could be the beginning of a fuel pump failure although I've been having this issue for nearly 2 years and it's no worse than before. Actually, my car used to stall once in a while long ago though it never happens now for which I'm thankful about...hope to get more feedback from the E34 experts here.

 

[miepower]

ICV might be the culprit

 

[skinhead]

ICV might be the culprit

2nd tht :top:

 

[kelvinjb]

3rd to support

 

[Hammer278]

Any estimate on the job for this? Did some research and you can actually DIY but it's not a small job. Not something I have the expertise in anyway.

 

[kgb]

can't it be cleaned?

 

[gorgon_ii]

ICV might be the culprit

:top: that right's...

 

[kelvinjb]

Used ICV is very cheap now. I have a pc for sale @ RM180 for 12V and RM230 for 24V.

Call: 0127840726

 

[skinhead]

dont change ur icv yet. u can clean it urself using any engine degreaser or even wd40. im sure the valve is sticky becos its dirty.

 

[anakin]

Bro Skinhead..have you sold your e34?,Seen one in Mudah.com just like yours..

 

[evilnickwong]

If you're cleaning the ICV, I've read that you should use Throttle Body Cleaner to dissolve and clean all the gunk. Difference with using WD40 or similar is that TB cleaner only cleans, it doesn't lubricate as the flap in the ICV needs a little friction to work. Just something to consider.

Btw, I had a similar problem on my E30 last time and it was the ICV too. A cleaning fixed it.

 

[koaygk]

thanks for the advise. may i know what is ICV and where it located? i would like to clean it myself first and see. thanks.

 

[skinhead]

Bro Skinhead..have you sold your e34?,Seen one in Mudah.com just like yours..

no lar bro. still hv mine. will advertise here when the time comes...

 

[jarance]

thanks for the advise. may i know what is ICV and where it located? i would like to clean it myself first and see. thanks.

From the MAF, trace the air intake duct to the throttle body. It should be around this area.

Have seen my mechanic taking it out from another car and spray with WD40 and shaking it to loosen dirt inside it. Dry with a blast of compress air and fix it back.

See pic below:-

 

[aangavatar]

i have the same problem, tried clean the ICV but that did not solve the problem untill i change with a new one.

 

[koaygk]

aangavatar, where you change your ICV and how much it cost?

 

[TCNG]

you can try to send to mechanice to clean the idling valve. cost less then rm 100. once clean, it last you quite sometime. i had the problem once.

 

[aangavatar]

i bought the ICV (bosch brand), RM520 from bavaria auto SS2 (ask for bro Lim). workmanship should not b more than RM80

 

[lane34]

Helo! Why not try to use scanner for the troubleshooting before you do any parts replacement . I have facing a same problem last year on my E34. 2 unit of CVT was replace but still have a same problem.Finally.... Is a ECU failure on Idling Engine Control circuit. After ECU replacement (secondhand)....the problem solve.

Regards