F Alonso

I have a 2007 C6 Z06 with a YSi and cam and am having problems with tuning the fuel with the Mototron 60# injectors. At idle, part-throttle and WOT is very rich. Even at WOT seems to not get leaner lowering the PE table. I am running 7psi of boost. I use LS2 edit.
I also installed an adjustable fuel preassure regulator and left the vacum hose connected, idle is set at 61psi (with hose connected.)

How do I get everything leaner???

Any help would be appreciated.
Thank you

dan@masportspeedshop

iTrader: (6)

Have you set the injector "Flow Rate vs. KPA" table?

If not, that's your silver bullet.
Cheers!

2xLS1

iTrader: (25)

You are going to have trouble running 60# 3 bar injectors with a PCM that limits the value you can enter in the IFR table to 63.5.

F Alonso

In the injector flow table the added values to the stock values go from 2.23 to 2.76 making a flow value of 7.49 to 7.99 (max the program accept) Is this correct?

What other parameters should I change? MAF tables???

2xLS1

iTrader: (25)

No that is not correct. Those injectors are rated 60@3 bar or 43.5 psi. Racetronix has them rated as high as 63.2@3 bar. You need to convert that to 4 bar 58 psi that your FP is. That puts them over the max value you can enter in the IFR table thanks to GM.

SSpdDmon

iTrader: (10)

What about dropping fuel pressure to 3-bar with the regulator and indicating the accurate flow rating of the injectors for that pressure? As long as the injectors are capable of providing enough fuel under boost at that level, that's what I'd do.

veee8

iTrader: (40)

Right, you trick the PCM.

2xLS1

iTrader: (25)

Explain how you are going to do that on a returnless fuel system with the regulator in the tank.

F Alonso

The Corvettes work at around 60psi ALL the time. I jus added a SC and a FPR. If I tell the computer that the injectors are smaller than reality, they will flod the cylinders with fuel.

SSpdDmon

iTrader: (10)

Sorry - misunderstood. I'm thinking about my setup (using an A1000 vac/boost referenced external regulator and factory lines). I was assuming he did something similar when he said he added a FPR.

veee8

iTrader: (40)

Yeah, but if you lower your base pressure, and adjust your injector flow rate, it will lean it down . Pulsing the injectors with less pressure, the PCM won't know how much pressure is behind it ( unless the 06+ have something different!) You will have to play with it. Now in closed loop part throttle it will try to keep it at 14.7-1, which is fine. Then under boost with the reference line hooked up, pressure will go up and so does fuel delivery. And you adjust your PE tables.

2xLS1

iTrader: (25)

PCM doesn't know what the fuel pressure is no matter what it is. It only knows what the IFR table is. And the IFR table needs to be correct for what the injectors flow with whatever the pressure is. This is one of those problems where everyone says oh just trick the PCM with the wrong values in the IFR table or your tuner should be able to tune it anyway, but I've yet to see a detailed description of ever table that needs to be hacked for the wrong IFR values or a cal posted where it's actually been done. There was one trick posted where you use the Flow Rate Modifier vs IAT table to scale the IFR table up, but it was also said that a lot of the OSs will ignore that table.
This is why I said you are going to have trouble running the 60s. Your life will be easier if you just go with an injector that will fit in the IFR table.

veee8

iTrader: (40)

Whats the problem with dropping fuel pressure to 43psi and setting IFR to 60?

2xLS1

iTrader: (25)

It has a returnless fuel system with a fixed regulator in the tank.
If you want to replumb the whole fuel system with an aftermarket FP regulator, they you could do it. Otherwise you are stuck with working with 58psi.

F Alonso

Please, read my post No. 1

I have a FPR and a return system

SSpdDmon

iTrader: (10)

That's what I thought....

People got me questioning myself today...

2xLS1

iTrader: (25)

My apologies. Some how I missed that. Then set the pressure to 43.5 and the IFR table for 60 lbs converted to the units LS2 edit uses.

F Alonso

Now I am going to throw something new to all this: The C6 and C6 Z06 have two fuel tanks and the jet pump in the right tank needs around 58psi of fuel pressure to send fuel to the left tank. So, if I lower the pressure, I will never use the gasoline in the right tank!!!