1999 LQ4 - Suggestions

[Cougar281]

We got the truck all back together (had an oil pressure issue that turned out to be a bad O-ring on the oil pickup) and I flashed in a 2002 LQ4 OS from holdencrazy. Changed the Vehicle platform options to remove the "F" terminal and disabled the associated DTC's, as well as fix the tire size (was calibrated for stock 245's but has 285's) and the truck is running like a champ. Seems to run better than with the original tune. Now I just need to look into safely adding some power... I don't want to blow his motor up .

[Steve Bryant]

I'm glad that you've got the truck running again and all seems well. Do you have a wide band oxygen sensor that will interface with EFILive? I have some suggestions on setting up your tune that I'll be glad to share with you.

Steve

[GAMEOVER]

Post up the current tune Cougar....

[Cougar281]

Post up the current tune Cougar....

Here are the original (Jon Stock.tun) and current (2002 Chev......)

And no, I don't have a WBO2 . I do need to get one for my car eventually so MAYBE I can learn how to tune it...

Not looking to do anything crazy with it. Primatily some "refinement". The end goal is to drop a Duramax/Allison in the truck, but until then...

[Steve Bryant]

Since you don't have a WB, you could work some on your VE Table and try to verify the accuracy of the MAF at Stoic, but I don't think that it's worth your time right now. After all, your running the stock cam and heads and in closed loop most of the time, so I wouldn't worry about tweaking the VE & MAF. What I would do is set the PE Time Delay from 60 seconds to 0 seconds. Then, I'd set up the Power Modifier Based on RPM {B3618} to an EQ of about 1.14 (theoretically a little less than 13.0:1 AFR), but you can't check it without a wideband. Right now, it's set up for pig rich in the upper RPM range.

Then I'd bump up the high octane spark table about 3 degrees across the board and see what happens regarding knock retard. One important point on timing is to not over do it and verify under towing loads (light, medium and heavy throttle). When the truck isn't towing, you can zip right through an RPM range that you might get a lot of KR when towing a heavy load. This is a big difference from a car or a truck that's never used for towing (especially heavy loads). Also, if like me, you always run 87 Octane, you can't bump up the timing a lot.

Steve