WOT timing discrepancy

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Meangreen
 

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Joined: Tue Dec 10, 2013 5:41 am

WOT timing discrepancy

Post by Meangreen »

Hello Everyone, I had typed out a long post but the site seemed to go down briefly right when I hit submit. Here is a more to the point version:

I am tuning a 1990 Z32 TT. During part throttle cruise, the logged timing values are consistent with the primary ignition maps. However, when at WOT the logged ignition values are retarded by ~6°. A new knock sensor is installed in the stock location. There are no DTCs and the primary ignition map is identical to the knock ignition map. There are no values in the vicinity of the accessed cell that are similar to the logged ignition (e.g. active cell has commanded 16°, log shows 10° and 15 is the lowest value on the whole MAP). Any help is appreciated.
bachig24u
 

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Re: WOT timing discrepancy

Post by bachig24u »

Is the neutral switch working properly?
Matt
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Re: WOT timing discrepancy

Post by Matt »

Try disconnecting the knock sensor, and turn off all knock flags in both timing maps (works around pulling timing when the knock DTC is raised). See if it still does it (ECU thinks its detecting knock)

If that doesnt work please post BIN and log file or email directly to myself
Meangreen
 

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Joined: Tue Dec 10, 2013 5:41 am

Re: WOT timing discrepancy

Post by Meangreen »

Yes, I confirmed this morning that the NSS is functioning properly.

Matt, I will hopefully have a minute to disconnect the knock sensor in the next few days. Stay tuned!
bachig24u
 

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Re: WOT timing discrepancy

Post by bachig24u »

I thought I'd mention it because some maps in neutral are set to 10deg on that model ecu.
RomChip200
 

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Re: WOT timing discrepancy

Post by RomChip200 »

ECU detected knock in the low range (<3000rpm, where torque is max) and applies retard to the rest of the map.
It will do so till it detects an acceleration WITHOUT knock.
ECU works in a "snowball effect" mode when retarding timing.
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