HP Tune files

ctuinstra

Goblin Guru
I have a lot of misfires after installing the 60lb injectors. But only at idle. Add even a little bit of gas and they go away. So my thought was simply to increase idle speed. That didn’t help, I increased all the way to 1200 just to see if they would go away and they didn’t.
I’m not surprised. I’ve read a lot how these large injectors are hard to tune down low. When they get that low and the pulses are that short, they start doing some really weird things. The rate is not even close to linear close to idle.
 

George

Goblin Guru
If you switch the fuel pressure regulator that references off intake manifold pressure it is easier to get idle mixture more manageable and have more flow under high boost.

Brad
 

JSATX

Goblin Guru
If you switch the fuel pressure regulator that references off intake manifold pressure it is easier to get idle mixture more manageable and have more flow under high boost.

Brad
You’re talking about a universal boost reference fuel pressure regulator like the aeromotive stuff?

I’ve been wanting to go that route but it’s my understanding there’s already some oem ECU control that accounts for this, I don’t want to put extra pressure on the fuel if the computer is already adjusting pulse width or something of the sort.
 

George

Goblin Guru
The turbo I think uses pulse width modulation to control pressure. Maybe even the N/A engine might need to research might need to check. By on a SS the pressure is locked by the internal pressure regulator. If you go with a boost reference regulator you will need to remap the fuel curve not a hard thing to do. It would decrease the flow at idle and increase the flow as boost goes up. The way it is now the car get leaner as the boost goes up so fuel flow is restricted. Because of the delta pressure differential. Have not changed mine yet.

Brad
 

George

Goblin Guru
Justin, on your current setup you could just install a SAAB fuel rail with regulator, put a standard fuel filter on and re-calibrate you VE easy peasy.

PS you will have to remove the pressure regulator spring and piston from fuel pump it becomes a return

Brad
 
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JSATX

Goblin Guru
Justin, on your current setup you could just install a SAAB fuel rail with regulator, put a standard fuel filter on and re-calibrate you VE easy peasy.

PS you will have to remove the pressure regulator spring and piston from fuel pump it becomes a return

Brad
Interesting. I’ve already removed the internal pressure regulator from the pump. I use a corvette fuel filter which has a built in 50psi regulator.
 

George

Goblin Guru
So if you have 50psi fuel pressure pressure constantly at 20psi boost you have a delta of 30psi at injector nozzle
at idle you will have between 55psi and 60psi delta all seem backwards for performance.

Brad
 

G Atsma

Well-Known Member
The Vette regulator actually regulates to 58psi if that matters, since it's used on an LS V8 all of which use 58psi as normal pressure
 

Ross

Goblin Guru
My 06 SS SC seems to be running great, but when I logged it in HP Tuners, I learned that my MAP sensor was broken.
As a result, the Fuel Trim tables were all on one line (the lowest setting of the MAP sensor).
I'm not sure how my engine was compensating for the missing MAP info, but it is replaced now.
Of course the LTFT table is way wrong, so it will take a while for the engine to re-learn fuel trims.

PS, Adam changed the forum to allow for HP Tuner Log files!
 

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ctuinstra

Goblin Guru
Yeah, both the LTFT and the STFT are maxed out. You can reset the LTFT (zero them back out) so they relearn from 0 instead of maxed out. I don't know if it will make much difference but assuming you fixed it and the LTFT should now be close to 0, you can get them there quicker by just resetting them in HP Tuners.
 
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