1992Vortec

i recently started tuning on my single turbo set up and have a few questions. i installed 60# deka injectors and thats when i started having problems. I changed the INJ-injector flow rate** to 60#/hr and made sure my displacement was correct but im maxing out my VE tables. I found a thread where RBob posted Offset Compensation versus Battery Voltage and Short PW Compensation versus Pulse Width but after entering those numbers it was worse. I know i can start changing the injector flow rates just wondering why using the correct injector flow rates would get me close on the VE table? I feel like im doing something wrong i know i had no issues with my 24# before switching to 60#. Im running fuel pressure at 43# and my duty cycle is at 30% at 5LBS of boost. Also Im new to running open loop and was wondering with the MAX lean afr means? Any help would be great thanks guys

RBob

iTrader: (1)

How are you deciding that the VE needs to be increased? How much boost are you planning to run? Those 60 #'ers will support 742 HP.

> was wondering with the MAX lean afr means?

That is the highest (leanest) AFR that can be commanded. After the open loop AFR is calculated, taking into account all of the adjustments to it, it is then compared to the max lean value.

If richer the cAFR is used as-is. If leaner, it is changed to the max lean value.

RBob.

1992Vortec

i have the low vacuum areas from 70 to 100 kpa set to 100 and its still trying to add fuel. running 5 LBS of boost and having problem with getting into the 11/12 afr range that i would like to run. I had 24lb injectors before this and did a pull with the turbo and it held 12 to 1 at 5lbs of boost but the duty cycle with at 130%. So i bought the 60# and been having a hard time getting it rich ever since. When i put in the Offset Compensation versus Battery Voltage and Short PW Compensation versus Pulse Width that you posted for another guy i had to bump my idle areas of the VE table into the 75 range just to get it to idle because it was leaning out to the point of stall. Thank you for your help

RBob

iTrader: (1)

Is the commanded AFR in the same 11/12-to-1 range?

{edit} To add to this, why do you want to run so rich at those load levels (70 - 100 KPa)?

RBob.

1992Vortec

the commanded PE afr is set at 12 to 1. the only reason i moved those to 100 was because i was leaning out in those areas at WOT like 16 to 1. After i moved those areas up high it did help get me closer to my goals but then i looked at the corrections on the VE learn and it was add fuel in the maxed areas. Also im at 5280 feet so 85 kpa is what i get key on engine off. Is there something im missing causing lean afr? ive been trying to add fuel as much as possible to stay on the rich side during these first runs.

Thank you

Street Lethal

iTrader: (16)

Throw up a datalog and a bin file.

It's easier to see what your referring to that way...

RBob

iTrader: (1)

1992Vortec, back to your original question:

> ...i know i had no issues with my 24# before switching to 60# (RBob: then being lean).

Two things came to mind, the fuel pressure may be dropping off.

Or the injector flow rates are not what they should be. Many years ago I ran into this when the 5.7l TBI injectors were supposed to be 55#/hr. With me replacing them with supposed 90#/hr BBC injectors.

It was lean. As the 5.7l injectors were actually 61#/hr, and the BBC injectors were actually 80.5#/hr. So the actual change in injector flow rate wasn't as large as it was expected to be.

RBob.

1992Vortec

Hey sorry for the late post i just got back in town going to get the datalog and bin file loaded up here tomorrow. i came home to my fuel pressure sensor sitting at the door so ill hook that up and do a run so that PID is in the datalog. I was going to ask you bob about the fuel pressure sensor i pick up i know its a 0.5V – 4.5V linear voltage output for 100 PSI. But didn't specify that it had a amplifier that i seen you talked about like the autometers had. Will this be a issue if it doesn't have an amplifier?

RBob

iTrader: (1)

The .5 - 4.5v linear output is OK, that is amplified. The real question is what is the power source voltage. Some are +5 V with the output being ratio-metric to that supply voltage. While others are 9 - 18 v with a built in regulator.

RBob.