1999 ls376/480 camaro question

Hey guys this is my first post. Snagged MPVI2 and a wideband before the holidays and have been slowly learning bit by bit and using these forums to try to diagnose whats going on with my car. Car has newish o2s, new plugs, and fixed a pretty bad exhaust leak today. i figured the exhaust leak was throwing off the o2s and adding tons of fuel and i can smell it ( havent setup the wideband yet but thats next),but it seems to act the exact same way after. The car has been tuned on a dyno twice before and seems to always end up being super rich not long after. Can anyone point me in the right direction looking at the scanner?

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Post a log file of it during idle, part throttle for now. And make sure you have logged the basics, like MAF Frequency, o2B1S1 o2B2s2 Short term fuel trims, long term fuel trims, MAP. If you need more help, Send me a PM

I thought I attached a log and the tune. Is it not showing?

Car has long tubes, rear o2s deleted btw.

Sorry, Didnt see the log. Ill take a look right now.

Short term fuel trims showing at times in low rpm region that it is pulling up to 15% fuel due it being rich. So yea, you are running rich. Just glanced at your tune file too and it isnt setup the way I personally would tune. Your LTFT are turned off completely....as is DFCO.

The cylinder volume isn't right for a 376 cubic inch motor.

Does it really have stock injectors still?

I don't see that being enough for the power this engine can make.

It may be worth adding that I believe the IAC was bad when it was on tuned last. Yeah I wasn’t too happy with that tuner overall, hence why I’m here now. Should I turn on the LTFT? I’ll do some more homework on dfco as well. Thanks for taking a quick look.

It’s as it came in the crate, they haven’t been changed.

So the LS376 came with intake/injectors all the way down to a oil pan?

If it did, then much more in the tune needs changing for the fuel injector data.

Quote:

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Originally Posted by 5FDP

So the LS376 came with intake/injectors all the way down to a oil pan?

If it did, then much more in the tune needs changing for the fuel injector data.

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As he said,^ needs work for an ls3 to operate properly, and yes, i would turn on the LTFT and try dialing in the VE, then MAF. You have a wideband ?

Yes, it was complete. Oil pan and accessories were swapped from the original engine, that’s it. Thanks guys I’ll look into those next. I do, the aem 30-0300. I was going to try to get that setup tomorrow.

There is a conversion spreadsheet for putting LS3 injector data into LS1 format.

If they are stock LS3 injectors I think this spreadsheet is already ready for that. If they are different part number and larger you can find that data from a stock tune with those injectors and plug the data into this spreadsheet to get things working.

Ive been messing with the spreadsheet some and ive been able to paste short pulse adder and min pulse and add them back to the tune, but i cant seem to directly paste the injector offset and injector flow rate tables because the tables aren't exactly the same size.

I gave it a shot, although i have very little confidence in it lol. Since the tables were not working for me i looked around on here for others doing the same thing and tried to apply what I could.


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