Cold Starts

[kwbimmer]

I have searched through everything on this topic (and there is a lot), but there does not seem to be anything I can find to help diagnose my specific problem....

On a cold start, my E34 will idle at 1,500. After it warms up, the idle goes up to 1,800 and runs perfectly. On a cold morning (below freezing), it does the same thing, but I have a lot of difficulty getting it started. It has always started so far (fingers crossed) but sometimes takes 5 - 10 tries, holding the key for 20 secs or so. It does not always happen, but on enough occasions to make me wonder if I will get to work !!!

Any suggestions for this??

Thanks,

DJ

[BillionPa]

WHOA... that idle speed is WAY too high, sounds like there is a massive vacuum leak somewhere. i believe your engine's natural idle speed is between 700 and 800 rpms.

[632 Regal]

agreed! Look/spray for intake leaks

[kwbimmer]

WHOA... that idle speed is WAY too high, sounds like there is a massive vacuum leak somewhere. i believe your engine's natural idle speed is between 700 and 800 rpms.

Really??

When I questioned my "BMW mechanic" he said that it should be this high for an automatic, and a standard has lower RPM

[DaveVoorhis]

When I questioned my "BMW mechanic" he said that it should be this high for an automatic

Christ, no. My automatic 525i idled at about 850rpm. Sounds like a serious vacuum leak -- check the rubber intake boot and all vacuum hoses for cracks -- or a sacked Idle Control Valve.

[BillionPa]

sounds like the "mechanic" needs to read his manual.

cracks after the air flow meter in the intake boot, or a punctured or disconnected vacuum hose would do it, possibly a cracked intake manifold or disintegrated gaskets.

i think there is a spring in the idle control valve. if it corrodes to nothing then any signal to open it will open it completely like when you are starting the car, and the idle will jump to 1500ish...

[Montreal525]

cracks after the air flow meter in the intake boot...

I don't want to anger any of the grand masters but my boot was cracked and all it did was give an annoying hissing sound. My idle was still constant at around 900 rpm's. I would eliminate that part as a suspect.

Jeff

[brosher]

Also see my posts on the fuel line check valve here:
http://www.bimmer.info/forum/showthread.php?t=28670

You may have both intake leaks and fuel drain back problems.

[BillionPa]

thats why i added more places to look, because a crack in the boot can still be throttled by the ICV. i really have never seen an idle that high caused my any kind of intake leak, there is most likely more to the problem.

[aston_jag_tech]

sounds like something that should be variable is sticking.

But a better description of the problem would help too. More info pa-lease