5.3 C10 Swap Idle Issue

[layinrocker65]

I have no experience with stock flex fuel LSs but I can tell you that the early style LS truck rails with the regulator in them sets the fuel pressure to 58psi. I’ve done more than 10 swaps with most of them being off the stock truck return rails. Even the corvette fuel filter regulators set the pressure to 58psi.

It’s a super easy thing to swap in another regulator or complete rails and check to see if that’s the issue. Hard to tell if the tune is the issue without seeing it.