Stumbling/Stalling during Idle

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Originally Posted by Mattglas

I did the test and this is what I found. When the key was turned the valve instantly turned all the way to the right (right being towards the center of the engine). Then, it held that position for about 10 seconds and slowly/smoothly went back to the original position.

I also noticed that the inside of the valve was coated with black soot.

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the black soot it normal but you can clean it. Was movement fairly smooth. Movement you observed would be Normal, so long as it didn't stutter during the sweep.

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Originally Posted by DMC5180

the black soot it normal but you can clean it. Was movement fairly smooth. Movement you observed would be Normal, so long as it didn't stutter during the sweep.

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It didnt really stutter, though the movement did get faster towards the end of it's travel.

I also noticed the mine seemingly has a bigger gap than yours. I included a picture just for comparisonhttps://uploads.tapatalk-cdn.com/201...1bc6ca3a12.jpg

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The stock idle ECU does not ever close the valve (idle motor) all the way. When I had the stock ECU it closed a little more than in your photo. But all that means is you have a little less control for holding the 775 RPM on a hot engine.

A video is probably better:
https://drive.google.com/file/d/0B2N...ew?usp=sharing

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Originally Posted by Bitsyncmaster

The stock idle ECU does not ever close the valve (idle motor) all the way. When I had the stock ECU it closed a little more than in your photo. But all that means is you have a little less control for holding the 775 RPM on a hot engine.

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Oh, interesting. This bit off topic, but do you still sell your microprocessor controlled idle ECU? I remember seeing it awhile ago and wanting to upgrade.

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Originally Posted by Mattglas

Oh, interesting. This bit off topic, but do you still sell your microprocessor controlled idle ECU? I remember seeing it awhile ago and wanting to upgrade.

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Yes, I still sell them. My ECU will close the valve completely if needed. That was one of the things I did not like about the stock unit and my car would idle at 1000 RPM when hot. But that turned out to be bad deceleration springs on the butter fly valves.

Here is a video I did when I designed my ECU.

https://www.youtube.com/watch?v=8YE_HG4ji8E

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Originally Posted by Bitsyncmaster

Yes, I still sell them. My ECU will close the valve completely if needed. That was one of the things I did not like about the stock unit and my car would idle at 1000 RPM when hot. But that turned out to be bad deceleration springs on the butter fly valves.

Here is a video I did when I designed my ECU.

https://www.youtube.com/watch?v=8YE_HG4ji8E

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Sweet, once I get this issue fixed I'll pm you about buying one.


In other news, while testing I noticed that when the cooling fans came on the car would suddenly start to idle hunt. Once the fans stopped the idle hunting stopped. Possible ground issue?

I took the car for a 10 minute drive and when I got back I let it idle to see what wolud happen. After a few minutes it stumbled itself to death and I was greeted with this:
https://drive.google.com/file/d/0B2N...ew?usp=sharing

I'm not sure what to make of it.

what did the smoke smell like? How much resistance was their when you first pushed down on the air plate? Pushing down that far would dumped fuel into the hot heads and any valve that was open. It could have just been fuel boiling off. or oil residue in the intake from crankcase venting. worst case would be coolant vapor steaming off. It just depends on what smell like as to what it might be.

With it stumbling to a stop, you probably have miss fires and some of the intake valves are open. So I would think that "smoke" is unburned fuel.