1987 z28 with 1999 ls1 swap with six speed

[davidadavila]

Hey Guys!

I need help tuning my ls1 1999 Z28- 3RD GEN with a cam swap(running stock tank with electric pump,long tubes,I got it to the point that it turns on and doesn't die by adding some timing in the tables, but it I rev it past 3 grand it backfires bad. I will post a log put i would like help with setting up with parameters to set up for a good log. I got a mail in tune and he loaded a tune for a 2002 manual car, so i already adjusted injector sizes but i know that 02 cars came with ls6 intakes, so who knows what else is wrong. thank you in advance for your help

David D

[decipha]

backfires out the exhaust as in ignition fault or backfires / pops through the intake as in a lean misfire?

If its stock with nothing more than a cam swap then it should be opposite where it revs up fine and down low at idle its funky on a stock tune

Verify the base fuel pressure is near 60psi first. An intake isn't going to cause it to run that poorly or do anything odd like that.

most likely from what your describing you need to put in accurate injector data.

[davidadavila]

thru the exhaust, the injector data has been corrected, i got it to idle but if i rev it pops thru exhaust sometimes specially cold. when it warms up not to many pops and it revs fine to 6000

[5FDP]

As said, how is your fuel pressure? That log shows that it's extremely lean based on fuel trims and no wideband o2 sensor data.

[davidadavila]

unfortunately I dont have a wideband yet, the car has original tank from the third gen. ill check the gauge when i get home tonight. thank you again for the feedback.

[5FDP]

I can guess that the 3rd gen camaro running that old school 5.7 did not request 58psi like you need for this engine.

A stronger pump is wanted.

[davidadavila]

I can guess that the 3rd gen camaro running that old school 5.7 did not request 58psi like you need for this engine.

A stronger pump is wanted.

Im sorry I was not so clear im running same tank with a high performance bosch in line unit

[davidadavila]

So i checked fuel pressure and its good any suggestions on where to start?

[5FDP]

Hard to say other than checking for major vacuum leaks or exhaust leaks pre-o2 sensor.

You only provided one log and that log shows a lean condition based on the o2 sensors and fuel trims. You could reset the trims and do another log and see what it's doing.

[davidadavila]

Ill reset the trims this weekend see what it does, thank you again

[WAcord]

with that high map and high iat I would check for intake leak.showing bad lean .

[evetune1969]

I am running a LS1/6spd in my 1967 firebird. No cats, 3inch exhaust, NSR cam, and ls6 intake long tube headers with 308 gears(373s coming next month or two). Is this your setup? My tune is not perfect but the car runs decent. PM me if you want to look at my tune.

Also You really need a Wideband O2.