Ls3 swap questions

[tor1965]

The reason I play around with my tune before I changes my engine is that the engine don’t perform as well as it should. And I am afraid that this is not related to the engine it selves.
After I have studied lots of logs, and have thought on when the engine act strange I think that the problems are fuel related. Most of my earlier loggings and auto ve were done just after engine warm up. Then when logging a longer trip in summer temperatures the values changes. I have a feeling that this might be because the fuel warms up.
I have a home made return fuel system with the regulator placed on top of the engine. I have also tried some different solutions for the EVAP system and found pretty much vacuum in the tank sometime. The engine is in an impala ss clone. The in tank fuel pump is a Granatelli hp pump, but it is mounted on a 91 caprice in tank module. That means that it just sits in the middle of the fuel tank without any baffles or the more modern “turbo system”.
My fuel gauge is wrong as on most of these cars. When it shows half it is less then ¼. I have found that on Impala ss forum there is a lot of people that have the problem that the lt1 engines acts strange when the fuel level is down on1/4. When they dragrace this cars they newer do it with less then a ¾ tank of gas. I think that my feeling that the car loses power is because my fuel pump drags air on heavy accelerations. It is also possible that the fuel pressure changes do to the heating of the fuel pressure regulator or vacuum in the fuel tank.
This entire theory and tuning attempt and most of the problems could probably be solved if I borrowed the fuel pressure gauge that I have on work. I could have used it for weeks if I wanted to. On the ls3 I am going to place the fuel pressure regulator under the car or use the corvette fuel filter with the regulator inside.

[tor1965]

Hi
I have another question.
I am working with my 12212156 tun file for the ls3 swap.
When I am trying to scale the ls3 map sensor in table C6302 (map sensor offset) the decimal numbers are rejected. Am I doing something wrong or does not the 156 os support decimal values in this table. If not, is there some workaround for this? The ls 3 map values are “map sensor offset” -0.31 and
Map sensor scaler 128.125000

[ScarabEpic22]

Have you set the tune tool to display the decimals out to your desired resolution? There's a button in the toolbar that lets you increase (and decrease) the number of visible decimal places, very useful. A cell might show 0 but be anything from 0 - .99 in it.

[tor1965]

Decimal button! So easy and yet so impossible to figure out

Thank you, Erik.

[ScarabEpic22]

No prob, simple little things that you wouldnt ever bother to check end up messing with your head! Been there, done that!

Glad you're up and running.

[5.7ute]

tor1965. I dont think you want to use the map sensor adapter with an ls3 map sensor due to different pin outs or something like that.(I cant remember exactly why I was told not to do this)I just used the ls1 map sensor with the adapter in the ls3's location. It needs a bit of sealant & a small bracket fabricated to hold it in but this has worked fine for me.

[tor1965]

The engine is in the car and it has been driven for about 1500 Km. The stock ls3 map sensor readings seam to be ok with the settings from the 2010 Camaro tun file.
I have done some work on the ve table, and the car runs fine. I still have to change the o2 sensors, so I need to fine tune the ve table later. The areas of the ve table that look a bit strange are the part under 1200 rpm. When logging it gives high readings during driving, but if I adjust the ve table up I got bad idle after startup.
I would not use any time on this before I have the new o2 sensors so this can wait.
My part throttle shift times have changed because of the 92 mm Nick Williams cable throttle body. The area of the throttle blade is much bigger and the TPS reading is obviously very low on normal driving. Is it possible to correct this in the tun? Without changing all settings where throttle position is used.