Guys i'm stumped on this one and i'm looking for some help. Here are the basics:
05 4.8 1500
EFILIVE COS3, speed density
s475
Deka 80lb injectors
Walbro 450/Walbro 255 in tank
-8an lines
e-85
Factory feed as return
AFPR set to 58psi
Water meth kit
The issue i'm having is kind of odd and i'm stumped on it. On a cold start the truck idles great, 1.0 lamba, rock solid idle. As soon as I back the truck up and take it down the street for the first drive of the day the truck goes pig rich once I get about 2 blocks down the street. .70 lamda, barely wants to idle, just rich. As soon as I bring the truck into boost it stumbles and misfires but once the truck spools and takes off it runs great. From there the truck will run fine the rest of the day. If I let it sit for a couple hours it starts right up and idles fine, runs great, never does this again. Next day, repeat, same thing again. I've pulled the plugs and they look fine. The only thing I can think of is maybe the e-85 is causing an injector issue after sitting overnight, and once the boost hits and the injectors flow more they knock out any crud? But i'm leaning away from that because the truck idles fine when first started. Then I thought maybe the water meth is dripping into the boost pipe overnight and once the truck starts to move it sucks the water meth that is sitting in the pipe. So I installed a check valve, but still same issue. Any ideas guys? I'm thinking of swapping to 91 octane for a tank to see if the issues continue. I should also note this didn't always happen, it just started 2 months after getting the truck running again.