Fuel Pump Trims

[swathdiver]

Going to look at a Tahoe in a few days with an intermittent starting problem. It's an '07 with the LMG.

What should long and short term trims for the fuel pump look like?

Mine are 1.2 or 1.5, can't remember.

For those of you with Torque Pro or Tech-2s, can you fellas check your key on and start pressures and post your trims please?

Mine keys on around 58 psi and always runs at 43.5, it's a 5.3 LC9.

@Doubeleive @gooffeyguy @SnowDrifter @kbuskill @iamdub Who am I forgetting?

 

[SnowDrifter]

Fuel trims are fine. Generally within 10% of zero is fine, with no more than a 5% discrepancy between the two banks. Or at least that's always been my rule of thumb.

Short trim fuel trims should trend close ish to long term

 

[kbuskill]

Going to look at a Tahoe in a few days with an intermittent starting problem. It's an '07 with the LMG.

What should long and short term trims for the fuel pump look like?

Mine are 1.2 or 1.5, can't remember.

For those of you with Torque Pro or Tech-2s, can you fellas check your key on and start pressures and post your trims please?

Mine keys on around 58 psi and always runs at 43.5, it's a 5.3 LC9.

@Doubeleive @gooffeyguy @SnowDrifter @kbuskill @iamdub Who am I forgetting?

I know mine runs 43ish PSI while running. Never looked at it before starting.

I wouldn't think fuel trims would have much effect on starting.

 

[iamdub]

You have any specifics of the "intermittent starting" problem? Slow cranking? Cranks fine but excessively long before firing up?

 

[Doubeleive]

Going to look at a Tahoe in a few days with an intermittent starting problem. It's an '07 with the LMG.

What should long and short term trims for the fuel pump look like?

Mine are 1.2 or 1.5, can't remember.

For those of you with Torque Pro or Tech-2s, can you fellas check your key on and start pressures and post your trims please?

Mine keys on around 58 psi and always runs at 43.5, it's a 5.3 LC9.

@Doubeleive @gooffeyguy @SnowDrifter @kbuskill @iamdub Who am I forgetting?

mine usually primes to 65 then drops to 43-45 after starting

 

[swathdiver]

Fuel trims are fine.

Fuel PUMP trims! LOL

You have any specifics of the "intermittent starting" problem? Slow cranking? Cranks fine but excessively long before firing up?

This is about Andy's Tahoe in the other thread. I'll put the Tech-2 on it but would like to know what's normal.

 

[iamdub]

This is about Andy's Tahoe in the other thread. I'll put the Tech-2 on it but would like to know what's normal.

Just checked it out for the first time.

 

[SnowDrifter]

Fuel PUMP trims! LOL



This is about Andy's Tahoe in the other thread. I'll put the Tech-2 on it but would like to know what's normal.

I figured typo

Fuel pump duty cycle? No idea what's normal

 

[BG1988]

You have any specifics of the "intermittent starting" problem? Slow cranking? Cranks fine but excessively long before firing up?

slow cranking could be the MAF sensor as well

common


sounds like my problem hahaha

 

[dross99_si]

slow cranking could be the MAF sensor as well

common


sounds like my problem hahaha

Slow crank as in the speed the starter is turning?
Or slow crank as in the starter is turning at normal speed but the engine takes a while to fire up?