Ok, I'm a novice on HPT, so be easy on me. Working on Father-in-laws C3500. I have tried my own 20/20 tune, but wasn't happy with results, too "peaky". So I followed the "McRats 20/20" guide and we really like this tune. Only issue we notice is the Idle. For lack of a better description, it lopes? or as he says, it "chuckles". I'm thinking an injector timing issue, but looking for advise from the skilled tuners on here. Thanks in advance. Tune files attached, I hope.
ok, made the suggested changes to the tune. Re-flashed to vehicle, started it and everything sounded great. He calls me this morning, and said its back doing the same thing. Chuckling/loping idle. So, do yall think this is a fuel qty issue? or a timing issue?
look at the PW tables (main pw, main pw no pilot and pilot pw) they are really high. I would put those back closer to stock. I don't know what else is changed over stock but the pw tables for the mild tune I did on my lb7 was just the all the pw tables multiplied by 1.2 and it worked good.