I hope I'm in the correct place for this thread. If not moderators please inform/correct me.

I am working on a 2000 Jeep TJ that has had a 2000 Silverado 5.3 transplanted. I did everything myself so far but am not doing so well getting it to run properly.

It actually runs fine but seems to be getting more and more lean the more I drive it. It's to the point now where I'm getting nervous about driving it for fear I'll be burning a piston or something.

This thread is kind of a continuation of my introduction post here:

http://www.gearhead-efi.com/Fuel-Inj...3085#post83085

Thanks to user steveo I have been able to start focusing on fuel delivery before I try to do any tuning on this setup.

In my intro threadf (in case anyone hasn't bothered to check it out) I have determined I wasn't getting proper fuel pressure when I started revving the engine. Today I decided to disconnect the vacuum line on the rail mounted regulator and test again before I start replacing parts. I linked a video in that introduction thread.

Since then I have taken the Jeep for a test drive and recorded the wideband gauge to watch the AFR. It definitely runs rich at idle now but still goes lean on acceleration.

Here is a shaky video of that test.

https://www.youtube.com/watch?v=osLMYH3iFbM

At this point I think I need to determine if it is a vacuum leak or a faulty fuel pump causing my lean condition. Or possibly the regulator restricting fuel flow? I was suspecting a vacuum leak early on in this swap but thought I had that ruled out. Now I'm not so sure.

I'm a complete newbie to EFI but I have rebuilt a few engines in my day including a 6.2 diesel a first generation 5.7 Chevy small block and a Jeep 4.0. I'm not a complete stranger to turning wrenches but I consider myself a shade tree mechanic at best and am ready to learn EFI.

If anyone has any suggestions I'm open to any and all.