High Idle when Engine Cold, But wait, there's more... Gold foil film on starter! Options

[ericread]

OK, not such a big deal, but for the past few months, when I first start my car the idle goes to about 2,000 RPM. Once the engine oil gets to the mid-way mark the idle drops to about 950-1000 RPM and remains there when ever I return to idle.

Is this normal?

I removed each of the spark plugs and each showed a slight bit of white ash, but no fouling or any other sign of abnormal wear. The car seemly runs great, with the exception of the higher idle when the engine is cold. My CHT shows the engine cylinder temp gets up to temp pertty quickly, but the idle seems to be entirely dependant upon the oil temp.

On another note, I was having some problems with the starter engaging after a long run. Typical instance of the heat getting to the starter. So I purchased some gold reflective heat barrier film and installed it on the starter and on the solenoid. Although the film has a self-stick backing, I also secured it with stainless steel ties. (I'll try to post some pictures tomorrow). It'll probably be a week before I make a long enough trip to see if it helps, but it sure looks cool!

I know Capt. Krusty doesn't believe in manufacturer specs, but here's their writeup:

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Our Gold Reflective Film has excellent heat reflective characteristics, yet it is very thin and easy to install. Capable of reflecting 78% of all radiant heat while withstanding continuous operating temperatures of 675° Fahrenheit (357° C) for a minimum of 8 hours.

Made from metalized polyamide polymer laminated glass cloth, with a special high temperature pressure sensitive adhesive. This film is very lightweight at only 5 ounces per square yard, and is easy to apply. The minimum air gap to heat source is just 1mm. Sold by the running foot from a roll that is 24 inches wide.
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I figure if gold foil reflective film is good enough for F-1 cars, it just might help on my starter...

Eric Read

[SirAndy]

OK, not such a big deal, but for the past few months, when I first start my car the idle goes to about 2,000 RPM. Once the engine oil gets to the mid-way mark the idle drops to about 950-1000 RPM and remains there when ever I return to idle.

Is this normal?

Yes, this is completely normal. It's called Vario-Idle and was pioneered by Bosch in the late 60s ...


The fact that your engine ran differently up until a few months ago simply means that your engine was broken and one day decided to fix itself.
(IMG:style_emoticons/default/shades.gif) Andy

[ericread]

OK, not such a big deal, but for the past few months, when I first start my car the idle goes to about 2,000 RPM. Once the engine oil gets to the mid-way mark the idle drops to about 950-1000 RPM and remains there when ever I return to idle.

Is this normal?

Yes, this is completely normal. It's called Vario-Idle and was pioneered by Bosch in the late 60s ...


The fact that your engine ran differently up until a few months ago simply means that your engine was broken and one day decided to fix itself.
(IMG:style_emoticons/default/shades.gif) Andy

Thanks Andy. I have really been diligent in cleaning up all of the little engine problems during the past couple of months. At this point, I can't believe how well everything runs!

Eric

[SirAndy]

Thanks Andy.

I was trying to be sarcastic ... (IMG:style_emoticons/default/biggrin.gif)


The engine will idle high when cold but should come down to a normal idle pretty quick, especially if driven.

If it takes longer than 5 minutes for the idle to come down, i'd check the AAR to make sure it closes correctly.

Actually, do you still have the stock FI? What size motor?
(IMG:style_emoticons/default/idea.gif) Andy

[ericread]

Thanks Andy.

I was trying to be sarcastic ... (IMG:style_emoticons/default/biggrin.gif)


The engine will idle high when cold but should come down to a normal idle pretty quick, especially if driven.

If it takes longer than 5 minutes for the idle to come down, i'd check the AAR to make sure it closes correctly.

Actually, do you still have the stock FI? What size motor?
(IMG:style_emoticons/default/idea.gif) Andy

'74 2.0L totally stock D-Jet. I have some valve guide oil issues, so I am looking to have the heads worked on this winter. (New valves, valve guides, weld and cut, new valve seats, new springs, magic pixie dust, etc...) The transmission has some issues, but I'm in for Dr. Evil's rebuild class in Pomona, CA (?) this fall.

I do need to note that prior to buying my teener about 3 years ago, I hadn't turned a wrench in over 30 years. Only through help from people like yourself have I been able to take a somewhat poorly running 914 and make it into a very reliable daily driver.

MY THANKS TO EVERYBODY THAT PARTICIPATES IN THIS BBS!!! Only through your advice and assistance have I been able to keep this in the road.

Eric Read (IMG:style_emoticons/default/driving.gif)