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HP Tuners LS1 - Timing being retarded after 2500rpm

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Hey guys, pretty fresh using HPtuners...

Have done a LS1 conversion into a Nissan Patrol.... Ran nice straight off the bat. Have deleted the MAF. Set MAF fail frequency to 0 to force it into Speed Density mode.

Went to start doing some tuning and first thing I noticed was the power curve was very rough. Checking the logs the commanded timing is down a little from 1000-2500rpm but I can account for that from the intake Air temp being 44 degree's so in the table it removes 4 degrees because of that... but after 2500rpm the timing becomes really erratic and even drops to zero.

I cannot find any other tables to account for this but im obviously missing something. I ended the entire table to be 10 degree's (except for at very low rpm 800-1100 where it seems to detect knock)

The log did the same with 6 degree's (4 degrees negative due to IAT) but once again after 2500 all whack...

Ive attached the log and the tune file if that helps

NOTE: I Had to rename the 2 files with .jpg at the end to allow me to attach them... just remove the .jpg extention and they should open as normal

Attached Files


Although I haven't seen this exact issue, I have seen spark related issues when changing to MAFless and the ecu isn't going into speed density mode.

I looked over your map and have made a few small changes I recommend you try.

1: I have applied a 1bar speed density patch.

2: I have changed the MAF DTC settings so it will log a fault in the ecu that the MAF is unplugged/out of voltage range although will not bring up a check light if wired. This also ensures it goes into MAFless

3: I have adjusted the burst knock tables so it isn't as aggressive.

4: I have removed some timing from the IAT Spark table as it was quite aggressive and it is not uncommon for these engines to happily sit at 40odd degrees IAT

When uploading this map you MUST select "Write" then "Write Entire" for Speed density patch to be applied.

This will take around 5minutes.

Also I am assuming the MAF has physically been removed?

Try that out and let me know if you have any issues!

Attached Files

Cheers that worked a treat!

One thing I find curious, doing a dyno pull from 1000rpm it shows knock retard unless I tune the timing down to like 0 degree's... is this normal or is it possible detecting false knock because the engine is labouring and rocking about.

Great! I'm glad that worked.

If you're starting your dyno pull at 1000rpm it wouldn't surprise me if you need 0 degrees timing on such high load at low rpm.

I generally like to start my runs at 1750rpm as it is not often anyone has their foot flat at 1000-1500rpm demanding power from an engine.

The scanner is quite accurate and very rarley do I see phantom knock and have to adjust knock sensor settings.

I would try starting the run a little later 1750-2000 and see what happens, my guess is it is knocking at 1000rpm with full load and then the retard decay will also be hurting power for the next 1000rpm or so.

Don't forget at the end of the day you have to give the engine what it's telling you it wants.

Thanks Chris, Makes sense...

Next problem is its a little lean from a cold start... But I cant for the life of me find the ECT fuel correction table?

Can find the ECT cranking correction but not for running :(

Found it... Open loop EQ Map!