Time for another update. Unfortunately it makes me look ignorant but I wanted to post it up in case it helps someone else down the road.

My initial problem was that the engine would start then...

Thanks. And to anyone that wants the stock 2003 Avalanche .bin in 9405 here it is.

Thanks for the replies. It occurred to me today at work that I may have jumped the gun posting this thread. I'll post a follow up when I know for sure but I think deleting the VATS may have been...

First off I want to start off informing anyone reading this I am a novice at tuning. I have very limited experience with EFI Live but I am trying to use the free tools right now.

To give the full...

Assuming you found it by now but it is the first sticky under OBDII Tuning. Here is the link:
...

It does enter PE. If I stab the throttle it drops to ~12 and never gets above 13 at WOT. If I accelerate slowly it stays close to 14. I should probably make a video to show what it is doing.

I...

I ended up driving the Jeep quite a few times this weekend. It seems to be running great and doesn't go lean with the current OS. I'm not sure if I'm going to change the OS back on this computer. I...

Thanks dave w. I was just looking at B3601 and seeing it is telling the computer to run at 14.68. Hitting 15 didn't seem horrible to me.

I was curious if I tried setting that a little on the rich...

So at this point I don't really understand why I would be running lean at every RPM/throttle position except WOT. What could be broken? If it goes rich at WOT doesn't that prove I'm getting enough...

Wait a minute. Time for a dumb luck update.

I was ready to step away from this for a couple days. I decided I'd take my dog to the park for a swim in the river. My dog loves to swim and it is hot...

edit: I did unplug the vacuum line but that didn't change anything. I tried it before and after OS change.



This didn't help either. It runs fine with the "stock tune" but is even more lean now...

I've been playing with this for a few hours today. I actually set the flow rate lower by 20% thinking that may help. It didn't. I tried all sorts of things. I tried modifying the VE by 20% by both...

It is a new return style vacuum referenced regulator.

Would the MAP sensor play into this at all? How would I test it? What is a "normal"reading for a stock engine at idle and say 2000 rpm?

I just verified changing the flow rate did not correct my lean condition. I then did a MAF fail to see it maybe the second used MAF is contributing to the lean condition. It is not. I am still...

I believe I found the original tune that was on the computer that I believe to be the stock 2000 Silverado computer. It was OS 09381344. In table B4001 it shows the injector flow rate at 3.1250.
...

I appreciate you guys trying to help me sort this out. I also appreciate you being patient with me. I know what it's like trying to help someone who you're sure is dense... And I am sometimes dense.....

So I did a couple things this evening.

I started off by taking it for a test drive to watch the AFR under a real load. At WOT it still goes about 15 AFR which is a bit lean. I decided I'd adjust...

Thanks dave w. I didn't really understand your post until B52Bombardier1 mentioned what it meant...

I set the MAF to 1Hz and tried it. It seems the MAF is causing my problem.
So is it common for...

That wasn't actually Torque. It didn't seem to have a lot of PIDs. I ended up using OBDLink.

I'm going through the tune now and failing out the MAF to test. I'll report after I have tested it.

I spent a few minutes and removed a couple spark plugs. The tips were light tan but the plugs were not new when I started this swap. The engine had these plugs in it when I swapped it in so I don't...

I will pull a couple plugs today. At least one from each side.

I do have a bluetooth OBD scanner. I will try it today to see what it will show for free. Otherwise I was thinking about buying...

Thanks again steveo.

Just to be clear I'm not trying to tune around any problems. I'm just trying to correlate symptoms. I'm just a shade tree mechanic. I'm trying to say I think I discovered I...

Hey steveo I didn't see your post until I responded to the other.

At this point I'm not really sure about anything. I really don't think it's a fuel pump or line issue though. My memory isn't...

This is what is in the PCM right now.

I've checked a couple times for vacuum leak but am contemplating building a smoke machine and doing a smoke test at this point. That's all that makes sense as...

I'm just about at my wits end. I just replaced the fuel pressure regulator. Still no change. Once I go off idle I see the AFR jump to 15-16 and climb to over 18 when I really rev it.

I'm not...