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Registered
Join Date: Oct 2007
Location: SWEDEN
Posts: 71
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Bad idle(cold start)
I have bad idle on my 911 SC -79 when cold start, it starts immediately but then it will oscillate between 1000-2000 RPM the first couple of minutes. If I hold the throttle at 1500 RPM for 15-30 seconds directly after start it will go down to steady 950 RPM. Have no problems when it's warm.
I shouldn't have any vacuum leaks, changed all tubes and gaskets when I had the engine out. Had the same problem before the engine was out. /Hans 911 3.0 SC -79 |
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02-12-2008, 01:04 PM
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Member 911 Anonymous
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Do you have an Idle Control Valve or like it? If you do when it hunts try tapping on it with a screw driver, if it clears up, there is your issue. my .02
Just checked you have a WUR, I check the OHMs on that thing.
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'85 Carrera Targa Factory Marble Grey/Black * Turbo Tail * 930 Steering Wheel* Sport Seats * 17" Fuchs (r) * 3.4 * 964 Cams * 915 * LSD * Factory SS * Turbo Tie Rods * Bilsteins * Euro Pre-Muff * SW Chip on 4K DME * NGK * Sienes GSK * Targa Body Brace PCA/POC Last edited by DRACO A5OG; 02-12-2008 at 08:59 PM.. |
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02-12-2008, 08:55 PM
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911_pilot
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Bad idle
Zacko,
There are a few things that affect idle. The easiest to check are the Oxygen sensor (if you have one), the idle control valve, and the have a mechanic check the air/fuel mixture. Very small vacuum leaks create bad idle. Double check this. I found that my Warm Air Regulator (I'm in Texas, so this is useless) was clogged and needed to be cleaned out with WD40. I have a better idle. A Bentley Manual is a wise investment.... 911_pilot |
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02-13-2008, 03:06 AM
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Designer King
Join Date: Mar 2004
Location: Toronto, ON Canada
Posts: 5,499
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Is this something new?
It's possible a PO richened your mixture to make up for an out of spec WUR or AAR.
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Paul Yellow 77 Sunroof Coupe/cork interior; 3.2L SS '80 engine/10.3:1/No O2; Carrera Tensioners; 11 Blade Fan; Turbo tie rods; Bilstein B6; 28 tube Cooler; SSI, Dansk; MSD/Blaster; 16x7" Fuchs/205/50 Firestone Firehawk Indy 500s; PCA/UCR, MID9 Never leave well enough alone |
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02-13-2008, 08:55 AM
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Registered
Join Date: Oct 2007
Location: SWEDEN
Posts: 71
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I don't think I have an idle control valve and no oxygen sensor and what is Warm Air Regulator ?? Is it the Auxiliary Air Regulator? anyway, I have clean up this this part to.
But I found something strange with my WUR, shouldn't the vacuum hose connection be on the short side of the WUR?? This is my WUR and it has the vacuum hose connection(8 mm) on the long side. It's says BOSCH France 0 438 140 036 on it:  Can someone have replaced it ?? /Hans 911 3.0 SC -79 |
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02-13-2008, 12:36 PM
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Registered
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Quote:
Quote:
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02-13-2008, 01:03 PM
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Registered
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Quote:
Bosch WUR 0-438-140-036 is for Porsche 928 application. You need a -069 or a WUR that has similar spec. to 0-438-140-069. Tony |
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02-13-2008, 01:16 PM
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Registered
Join Date: Oct 2007
Location: SWEDEN
Posts: 71
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Thanks Tony,
do you now the difference between WUR 0-438-140-036 and 0-438-140-069 ??? I think it have been there for a long time! /Hans 911 3.0 SC -79 |
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02-13-2008, 01:41 PM
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Marble Grey
