Idle Control - BMW Forum

Bunny Capricorn · 09-01-2005, 03:47 PM

A month ago my 88' e30(155k) did not want to start back up after a nice run. Cranked but didn't hold idle, so I checked my Idle Control Valve and I herd a busing noise coming from it. To make a long story short I ordered another; popped it in and it cranked back up. The only strange thing at that point is with the new ICV I still herd that bussing noise, but since it started up and held idle I left it alone.

Now.....a month and a half later with intermediate driving....I'm in my car; running errands....I stop for gas and when I try to crank it didn't want to hold idle again. Now I was damn near in the process of calling the tow truck but I tried it again for the 5th or 6th time and it cranked(after about 10 to 15 min. of waiting).....

So my question is.....I got a brand new ICV and I still hear the busing noise coming from it. Where else should I focus my attention so I can solve this problem. I do have to say when I unplug the ICV valve the busing noise obviously stops. But I do not want to cause any damage to this new part..so were should I go next????

DJProfessor · 09-01-2005, 04:11 PM

unplug it and see what happens.

hanging parts is for american car mechanics. diag the problem and you won't spend as much in the long run.

Paraklas · 09-01-2005, 05:46 PM

Check the idle control valve relay and contacts for corrosion for start. Next I would check the fuel pump. My E30 wouldn't hold Idle and (while I was waiting for the tow truck) I poped the rear seats out and removed the 4 screws of the rectangular cover which revealed a non-working fuel pump.

nukeduster · 09-01-2005, 09:00 PM

icv's always buzz in e30's/in general.

DJProfessor · 09-02-2005, 08:15 AM

Quote:

Originally posted by Paraklas@Sep 1 2005, 04:46 PM
Check the idle control valve relay and contacts for corrosion for start. Next I would check the fuel pump. My E30 wouldn't hold Idle and (while I was waiting for the tow truck) I poped the rear seats out and removed the 4 screws of the rectangular cover which revealed a non-working fuel pump.

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good advice.......but the tank pump is just the transfer pump i do believe. the main pump is underneath the car (at least mine is on my E motor car)

Bunny Capricorn · 09-02-2005, 08:56 AM

But if it is the fuel pump, would the car run normal? Becuase it only gives me problems on a warm start.

DJProfessor · 09-02-2005, 03:16 PM

Quote:

Originally posted by Bunny Capricorn@Sep 2 2005, 07:56 AM
But if it is the fuel pump, would the car run normal? Becuase it only gives me problems on a warm start.

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DING DING DING!!!!!!!!

isn't there a thermo time switch of sorts for these things? something that regulates the warm up cycle?........i would be curious about that........

and yes it could also be the fuel pump. a bad fuel pump will often work when it's cold but when it gets warmer it freezes up.

pay more attention to how she runs when she is cold vs. when she is warm. that might also help shed some light on this issue

Paraklas · 09-02-2005, 04:30 PM

My fuel pump died a couple of times (cold and warm engine) and also after long and short trips so I would say that it's just a matter of time before it completely stops working. The problematic pump was that inside the fuel tank.

I also tried (when the car wouldn't start) to test whether fuel was actually coming to the engine by removing the fuel hose after the fuel filter and I saw that no fuel was coming out while I was cranking it.