Im bout to pull my hair out trying to figure out this new engine combo. Its an iron 2003 6.0 block bored with LS3 rods and pistons, 24x crank, 243 heads, comp pushrods, stock rockers, holley high ram, 80lb injectors, 88/83 turbo... NOW, i have an LS9 cam in it with LS2 front timing cover and cam sensor with 1x timing gear.

We have messed with thing since December trying to get it to run. It's extremely rich and rolling gas smoke out the exhaust, backfires sometimes while trying to fire it up and hasnt been driveable yet without problems. Its being tuned with hptuners and nobody has been able to make it run yet without flooding itself. 58psi fuel pressure and i extended the cam sensor plug to the front timing cover and switched the outside 2 wires per directions on the internet for LS9 cam/1x gear swap.

Any ideas what we have wrong here??? Im bout at my breaking point with this thing!!

Thanks for any help you guys may have,
Jamie

 

Do you have good tuners working on it? It's safe to assume the injector data is correct? Just want to make sure.

You are running a Gen 3 PCM I assume? Are you getting any codes?

 

Yes everyone are very good tuners that have messed with it. Injector data can be moved around just trying to make it do anything different and it still floods and cracks and pops. No codes. 2003 computer/blue/green plug for 6.0/4l80e

 

Are the injectors clean? Is one or multiple stuck open? Do you have a wideband? What is it reading? Are your narrowband O2's hooked up? Are both sides reading the same?

 

Checked fuel pressure?

Coils plugged in correctly?

Throw in a set of stock injectors.

Crank sensor working?

 

Brand new deka 80lb injectors, AEM wideband and it constantly wants to read 10ish... extremely rich. Stand alone harness and no 02 sensors. Harness has been on a couple of my other vehicles and worked great so i rule that out as an issue thus far.

-Fuel pessure is at 58lbs.
-Complete coil packs and rails were set off the stock 6.0 and right back on when this engine was put together. I surely hope side to side doesnt matter when took off and put back on aslong as correct coil harness is plugged in??
-Ive tried a new gm crank sensor aswell as a parts store BWD brand and no changes.

 

Are you sure they are 80s?

Coil packs dont matter side to side, if you didnt touch the harness they should be fine then.

Start dicking with the injector flow rate until you get it close. Are they rated 80lbs@3bar or 4bar? If at 3, then they are actually 92lb/hr at 4bar. If its stupid rich then that means the injectors are larger than the computer thinks, so increase the IFR 10-15% at a time until it gets close.

 

The injectors came from lightning Force Performance and are packaged as seimen deka 80lb. Ive used that company a few times for injectors like these with no issues. Im lost here and so frustrated.

 

Is the ect sensor plugged in?
Is the iat sensor pkugged in?

If either kne if these are unplugged it wil dump more fuel then you can adjust for

 

Just checked the package. 3bar/43