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Quad4444

Ford iacv reacting slow when returning to idle

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I have a ford isc valve hooked up on my 2jz with link G4 storm. 

The issue I am having with it is when I rev the engine the valve seems to shut off for about 5 seconds staying wide open holding revs at about 2k. This also happens each time I start the engine. It's as if when ever it is turned off it is taking to long to turn back on. 

So what I have done with the tuning of it is trying different frequencys between 150 and 600 hz then I have gone threw the isc solenoid setup process in open loop and closed loop multiple times thinking I wasn't doing something right there. I have also tried to set max clamp to the same duty cycle As I have is set to on the 2d table. Also I have tried fiddling with the gain in closed loop. 

After that 5 second or so delay the isc seems to be doing a great job at maintaining my target idle  rpm. 

Maybe I just have a bad iacv an need to try a new one.

Any input will be greatly appreciated. Thanks!

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isc issue map.pclr

isc issue log file.llg

ive found that no matter what when the iscv shuts off by turning off the car, revving, going above 5% tp or un plugging the iscv. The valve opens to a position where revs are about 2000 Then when turned back on by link it takes about 5 seconds to react and go back to desired position.

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The settings in your map doesnt match the log so its a bit hard to see all of whats going on.  Your log shows it was in open loop but your map is set to closed loop.  The frequency of aux one might be a bit high for that valve, try it around 120Hz.  

In your log below, the idle valve was just fixed at 35%.  Ive marked two areas, what made the RPM jump up in the first box then fall again in the second box?  Was that you unpluging valve or something?

R7cOoMd.png

 

 

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in the middle of logging an saving the map for some reason I had switched it to open loop.  I've tried 120 frequency and it doesn't seem to make any difference. In that log. What you marked is the exact thing that I'm talking about. I didn't do anything or change anything. All I did was revved the engine in the first box. And the isc opened up and didn't react (close) till the second box. Revs were stuck at about 2k between the 2 boxes you marked. 

I see on that log where it shows it's givin duty cycle to the isc. Maybe my valve is bad. I'll go pick one up from the parts store asap. 

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If it still does it with the valve unplugged then I would suspect ignition hangup two things you can try:

At -80kpa and below I would put 30 degrees of ignition in at 4000 revs and then highlight between 1000rpm and 4000rpm and interoperate between, which should make that point its hanging up a more reasonable 21 degrees.

OR

Use Idle ignition control to pull ignition out when idle conditions are met.

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it doesn't do it when valve is un plugged. What I meant is by un plugging the valve it opens then when plugged back in it takes time to react. Just like when it is turned off by link by going above a certain throttle % or past a certain rev. Shouldn't the valve close when shut off? Instead of open.

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1 hour ago, Quad4444 said:
1 hour ago, Quad4444 said:

Shouldn't the valve close when shut off? Instead of open.

it doesn't do it when valve is un plugged. 

You have the Idle Base Position set to 35% so this in the minimum the valve will shut, try changing the min clamp value to 15 and take 50% out the Idle Base Position Table, and play around with that, get this near perfect then turn closed loop back on.

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19 minutes ago, Quad4444 said:

I haven't yet. Are you thinking that trick will close the valve correctly? Cause I can phisically see that it is the valve staying to far open for the time it revs at 2k

Then I would think its a sticky valve.

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So I tried a new valve and it is still acting the same. I found the lowering the frequency to about 60- 80 hz makes it react more quickly and not hold high revs. But with frequency that low the valve is really unpredictable. 

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