I logged almost 30 minutes of data today, using EFI Live. LTFT's were reading 25.0% almost the entire time. Every once in a while they would read in the teens. Final average after 30 minutes was 21.0%.

The last time I logged part throttle driving was last summer but at that time they averaged -5%. I have the exact same set up now so I can't figure out why they would be reading so differently. Could it be a reading error with EFI Live?

Please help.

 

I'm not sure, but I was wondering if your car seems to be running just as strong as before? Could you have developed a leak somewhere? Exhaust, intake, headers?

It would be great if you could get a hold of a different scanner and compare the results.

 

The car is running as strong as ever. No obvious leaks. Only change is the SSRA, which I installed a few days ago. One thing that has been different as of late is the idle. My idle is set for 850 but it wants to idle at 1300. It won't idle any lower than 1300 for some reason. Everything else is normal.

 

That sounds like a vacuum leak somewhere(lean condition) on both issues you have.Or unmetered air coming from somewhere in the intake air tract.

 

i just had a similar problem. My fix was that the ls6 intake i swapped to didnt have the oring gaskets in it. Is it in both banks or just one? Can you smell the fuel? how is your mpg?

 

Before my cam install two summers ago my gas mileage was 19. After the install it dropped to 9 mpg. But just last summer my LTFT's were averaging -2 to -5. And my car has always ran well, even now, so I would have never known any different had I not logged some data today.
However, I have been smelling fuel lately after I park my car in my garage. I will recheck the air lid, maf and bellow conections just to be sure. The intake has never been off the car so I doubt the problem is there. I did install a ported TB last summer though.

 

Oh and it is in both banks. More than half of the time they were both reading 25.0%.

 

You didn't mention the high idle before. I'm pretty sure, as Ray said, there's unmetered air getting through. +25 is lean as you know, so you're getting too much air. Check everything around the air induction systems, intake. No EGR on an '02. Not much else it could be. It's unlikely that the scanner is the problem.

 

OK, I think I found the problem. I was listening to the car idle and heard an air sucking noise. I quickly found where it was coming from. There is a 3/4" hose marked GM 6188-M that comes from the back of the intake and looks like it is supposed to connect somewhere near the master brake booster. I no longer have power assisted brakes (had manual brakes installed a couple months ago) so the tube is not connected to anything. It is sucking in air through the opening. The end is a plastic end piece that looks like it should connect to another hose. I can't figure out if this is just part of my AIR system that I removed LONG ago or if this is actually supposed to connect somewhere. Or is this the tube from the AIR system that was supposed to be plugged up and maybe the plug fell out recently.

Here's a picture:

http://img.photobucket.com/albums/v6...Z28/Easter.jpg

Any ideas on what this tube is and what I should do? I really need to look at another '02 LS1 and see where that tube is connected.

 

back of the intake mainfold is 2 vacuum lines, 1 for HVAC controls and a second for brake booster... (and if you have a vacuum modulated transmision, they'll tap off the brake booster line for vaccuum reference)

The thin line is for HVAC items... the thick one is for your brake booster ... If you have manual brakes now you should be able to cap that off and be fine ...

 

Thanks Horist! I added a picture to my previous reply but based on what you are saying and what I already suspected, it was previously connected to the brake booster. I'll cap it off and hopefully my LTFT's will be back to normal. Thanks again.

 

Problem solved! Idle is fixed and LTFT's are back to normal (Avg.+3). I just wrapped some electric tape around the tube end. All sealed now. Thanks guys.

BTW, I actually raced my Camaro like this a week ago. I hope it didn't hurt anything. I wonder how much my ET was effected by it. I mean, if my LTFT's were reading 25% before WOT, won't it decrease a ton of fuel?

 

yup, that's definetly for the brake booster w/that big of a vacuum leak it'll be adding tons of fuel part throttle and I believe it should add more fuel at WOT to try to compensate for this unmetered air...

 

I'd do more than just wrap tape around the end of that hose. That sucks dirty outside air straight into the cylinders & will eventually destroy your cylinder walls. At the very least, bend it over securely to pinch it closed.

 

big ole air leak. Hey if you want me to tune the sucker let me know when.

When you were running at 21+ your PE will be over compensated, probably didn't go lean at the track.

 

Yeah I think I had it backwards. If the PCM is sensing a lean condition it will add fuel, not decrease it. So I was probably running pig rich at the drag strip the other weekend. I guess 11.30 wasn't too shabby afterall. Maybe I'll get that 11.1x tomorrow.

Josh, for now I'm almost done with the tuning. I'm being very basic about it. I adjusted my MAF table to bring down my LTFT's to -2. Next I'm going to dyno tune it using the PE table and shooting for a 12.8:1 air/fuel ratio. I'll be done then, at least until I get the G5X4 and bigger injectors.