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Hello everyone,

Just thought I would post this on here because I cannot seem to find out why, at idle, my car's RPM will jump up and down like a nutcase. Basically sounds like it has rotational idle at times but it doesn't.....

Basically, what is happening is that when at idle, I have noticed in the "Monitor" function that the ignition timing will jump around. Say from 20, to 0, to 15, to 2, to 5, to 20 etc. This seems to be what is causing the "hunting" RPM. Even though the settings on the IGN map says to sit at 15 at idle. Most of the time it will sit at 20....or jump around.

What the **** is going on as myself, a local tuner over here as well as another workshop cannot figure out what is wrong.

The car has not had a full tune as of yet, but the maps have just been cleaned up to suit larger nismo injectors as well as 80mm AFMs.

Any help is greatly appreciated! :P

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https://www.sau.com.au/forums/topic/58208-power-fc-hunting-rpm/
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Default ignition setting at idle is supposed to be 20 degrees

Has the FC got the default map or a previous tune from another car in it...? If you had the FC previously and was running without dramas before the injector and AFM change, I'd say the problem is with the new settings.

The fluctuating ignition may be causing the hunt @ idle, or it may be the other way around. If the hunting idle is getting close to stalling, it may be causing that fluctuation.

Datalogit does may things a lot easier, as you can save your map than initialize the FC to default settings and have a fresh start.

Power FC was fitted new with default setting when the Injectors and AFMs went in. Like I said though, even with the IGN map set to 15deg at idle, it will sometimes sit on 20, 15 or fluctuate to whatever it feels like. Shouldnt the FC follow whats on the map and not have a mind of its own?

It wouldnt have other maps from a previous tune in it seeing as it is new, but yeah I agree with you. Something in the settings must be causing it to fluctuate like this :)

When the IGN timing is stable, say at 15deg where its supposed to be, then the revvs are fine. It does not hunt. It just seems to have a mind of its own as it only occasionally does this.

Guest two.06l
The car has not had a full tune as of yet, but the maps have just been cleaned up to suit larger nismo injectors as well as 80mm AFMs.  

Any help is greatly appreciated!  :)

Check your injector seals as we had the same problem when fitting new injectors and found the new seals were the culprit. Put our old seals on our new injectors and bingo, no more hunting.Paul...DIRTgarage.

Check your injector seals as we had the same problem when fitting new injectors and found the new seals were the culprit. Put our old seals on our new injectors and bingo, no more hunting.Paul...DIRTgarage.

Paul,

I had the injectors serviced before I had them fitted so maybe it is the new seals that they fitted? I'll look into it!

Cheers! :)

Guest two.06l
Paul,

I had the injectors serviced before I had them fitted so maybe it is the new seals that they fitted? I'll look into it!

Cheers! :)

you might discover that they are squarer (is that a word..lol) on the edge and slightly thinner, resulting in an air leak. Also check the top seal for thickness against the old ones as they may look the same but are different also. good luck.Paul...DIRTgarage.

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