BlackGMC

iTrader: (31)

A buddy of mine is having a fuel trim problem and the tuner thinks it is either a intake leak or low fuel pressure.. So we are going to try and find the leak today, any tips/suggestions/advice to finding a intake or vacuum leak?

I was thinking of hooking up my laptop and logging idle fuel trims, STFTs and LTFTs and then hose the intake down with carb cleaner and seeing if the trims change... Sound like a decent idea??

thunder550

iTrader: (70)

That's what I would try first. I've heard (never experienced) that you'll be able to hear a change in the engine sound as well when you do that.

CurtD

iTrader: (7)

You should be able to spray some in specific areas ( like by 1/3, 2/4, 5/7, 6/8) and the idle will raise . That way you get a better idea where the leak is.

BlackGMC

iTrader: (31)

Thanks guys, we will give it a shot this afternoon, hopefully we find the leak...

2005 Silverado

iTrader: (19)

Old school, use a burnable gas around the intake, and listen for the motor or rev up...i hears it dangerous, but oh well!

Dustin

BlackGMC

iTrader: (31)

Mmmmmm, I think I will pass on pouring gas on a hot engine...

2005 Silverado

iTrader: (19)

No like a gas gas, not liquid gasoline, like a butane torch (not lit of course)

Dustin

BlackGMC

iTrader: (31)

Ahhh, that makes a little more sense....

53RUSSELL

iTrader: (9)

When my intake was leaking long fuel trims were max out at 25%. Try tightening up the intake bolts 1 or 2 turns see if the Long fuel trims go down. I just replace the gasket and it solves my problem.

budhayes3

iTrader: (19)

Carb/intake cleaner is what I've always used...