Author Topic: Cold start fast idle  (Read 4502 times)

stickandrudderman

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Cold start fast idle
« on: November 17, 2011, 00:09:49 »
As Tosh has been posting, we're doing quite a bit of work to his car.
Whilst she's been in the workshop for such a long time I've begun to notice that she doesn't cold start as well as she might.
A quick check with the test light revealed no power to the supplementary injector whilst cranking and further investigation revealed a failed thermo-time switch.
With power now restored she starts up willingly from cold but the cold idle isn't good so I took a look at the auxilliary air filter and found it to be partially blocked.
I thought it would be a good idea to take a video of this as it's really such an easy test and these little filters are so often overlooked. Very few of the many cars I see have had new ones fitted recently.
With a COLD engine, loosen off the air filter so that it's just in by a couple of threads. Start the engine and then remove the air filter whilst the engine is running. There should be a significant noise of suction from the orifice now exposed but there should be NO increase in the idle speed. If the idle speed does indeed increase then you hace a blocked auxilliary air filter and it should be changed. A final test is to install the new filter whilst the COLD engine is running and you should observe a significant drop in noise but NO significant drop in idle speed.
Here's a link to the video that illustrates this:
http://www.youtube.com/watch?v=VXZwHvdlNTE

Whilst I was at it I thought I'd check the throttle switch for function and it turns out that that isn't working either but that's another story........

mdsalemi

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Re: Cold start fast idle
« Reply #1 on: November 17, 2011, 13:09:31 »
Stick, Tosh--

Great little video.  Someone should add the part number and if the part (air filter) is still available?

Has anyone considered creating a dedicated youtube "channel" just for videos created by members here?  I don't know too much about it or how to do it, but some of my friends in other walks of life have dedicated channels on youtube.  Might be a nice way of organizing them.
« Last Edit: November 17, 2011, 20:09:30 by mdsalemi »
Michael Salemi
Davidson, North Carolina (Charlotte Area) USA
1969 280SL (USA-Spec)
Signal Red 568G w/Black Leather (Restored)
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2024 Ford Mustang Mach Ex PEV

stickandrudderman

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Re: Cold start fast idle
« Reply #2 on: November 17, 2011, 15:36:49 »
Two different part numbers according to your model:
000 075 11 32 for 250/280 or 000 075 06 32 for 230