I just got my 02 5.3 L59 put in my 91 rcsb. It is running very rich and barely running. It has trouble starting and a lot of trouble idling. I have a TR220 cam and longtube headers. Nelson did my tune and was aware of the cam, headers, and flex fuel motor. My friend brought his scan tool over and showed a few codes as well as the wild fuel trims.
I have the following data and info that I wrote down:

Codes:
P0785 - 3-2 shift solenoid control circuit
P0178 - fuel composition sensor
P1860 - TCC pulse width modulation solenoid control circuit
P1689 - Traction control delivered torque output circuit

Scan tool data:
Short term fuel trim - 50%
Long term fuel trim - 25%
MAF - 14 grams
MAP - surging between 52-76 kpa
Bank 1 Sensor 1 - fluctuating 38-900mv
Bank 2 Sensor 1 - fluctuating 500-776mv
Injector pulse width - 14.5% both banks
Barometric pressure - 98kpa
Coolant temp - achieves 210 degrees
Fuel pressure - key on - 60psi
Fuel pressure - idling - 46.3psi
Fuel pressure - regulator unplugged - 53.3psi

This is a crappy video I took of the scan tool while it was idling. Maybe you guys can make somethin of it.

I am afraid Allen forgot to tune it for flex fuel injectors....

To be honest, I dont really know what any of that stuff means I just know thats what the scan tool said and what my friend (who is a gm tech) said is important. He says its very rich and even I know that from the smell and smoke of the exhaust.

Advice?

BTW - my build thread is here http://www.ls1truck.com/forums/lsx-t...s-prime-9.html if anyone is interested.