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And give a newbie a hand with this tune? 5.3 stock rotating assembly .553.553 110ls cam beehive springs cathedral heads with little port work flex fuel injectors truck intake, in front of a sm465 "3 speed" np205 4:56 gears and 35" tires. Only got limited data and no load pulls till tomorrow but if anything is obvious to you guys and you could help me out that would be great.
There is more than one stock "flex fuel" injector. You need to list the actual part number off the side of the injector before anyone can know if you have the right info in your tune. Verifying the fuel system pressure and whether it is referenced to manifold is also necessary. Knowing exactly how much fuel you are spraying is the basic foundation that all the other parameters in the tune are based on.
There is more than one stock "flex fuel" injector. You need to list the actual part number off the side of the injector before anyone can know if you have the right info in your tune. Verifying the fuel system pressure and whether it is referenced to manifold is also necessary. Knowing exactly how much fuel you are spraying is the basic foundation that all the other parameters in the tune are based on.
Got it will get part number when I make it back home and will have to get my hands on a gauge to verify pressure which is manifold vac regulated. Sounds like I shouldn't trust the AFR reported back by OBDXplorer either from what I am reading?
Got it will get part number when I make it back home and will have to get my hands on a gauge to verify pressure which is manifold vac regulated. Sounds like I shouldn't trust the AFR reported back by OBDXplorer either from what I am reading?
The factory narrowband sensors are ONLY good for reading exactly stoich, and showing if there is some amount of deviation above or below. As long as you are targeting stoich the reading should be fine. The one situation where this is not usually the case is if you are idle tuning with a cam that has a lot of overlap. Sometimes you will get a false lean reading with ANY o2 sensor at idle in that case. When targeting PE, you need a wideband to tell what is really going on.
That looks like an l59 injector, assuming the number I can't read is a 4. They came in stock applications with both 51psi and 58psi. Find a 2005 and up stock file, and it will have all the injector data for 58psi.
edit-- For a vacuum reference system, of course you just copy the 0kpa values all the way across the IFR and offset vs V vs VAC tables.
looks like according to this rented gauge it is hitting aty 60-61 psi. Can that be right or do I have an issue with regulator I need to chase down?
That is within factory spec for a 58psi system. Usually the only issue with those old factory referenced return regulators is that eventually (they are all pretty old by now) the internal diaphragm fails.
That looks like an l59 injector, assuming the number I can't read is a 4. They came in stock applications with both 51psi and 58psi. Find a 2005 and up stock file, and it will have all the injector data for 58psi.
edit-- For a vacuum reference system, of course you just copy the 0kpa values all the way across the IFR and offset vs V vs VAC tables.
Sorry but what do you mean? I'm green as can be when it comes to tuning but what V=? IFR=?
Sorry but what do you mean? I'm green as can be when it comes to tuning but what V=? IFR=?
IFR= injector flow rate. V= voltage. You will need to make sure all the tables match under engine>fuel>general>injector control. The tables that you may not exactly copy are the injector flow rate table and the offset vs volts vs vacuum table. Those tables just need the value for 0 vacuum put in all the way across, because you have a vacuum referenced regulator maintaining the pressure differential across the injectors.
IFR= injector flow rate. V= voltage. You will need to make sure all the tables match under engine>fuel>general>injector control. The tables that you may not exactly copy are the injector flow rate table and the offset vs volts vs vacuum table. Those tables just need the value for 0 vacuum put in all the way across, because you have a vacuum referenced regulator maintaining the pressure differential across the injectors.
Ok thank you for clearing that up. Found it and cleared table to all 0's.
Ok thank you for clearing that up. Found it and cleared table to all 0's.
NOOOOOOO! You don't zero any values. You use the numbers from the 0 manifold vacuum column in all the columns, so that left to right you have the same numbers going across. The first pic is non referenced style data, and the second pic is the way you will need to enter data, but those are from 2 different tune files and the numbers in them have no relation to each other.
Last edited by gametech; May 23, 2025 at 11:59 PM.
I don't have HP Tuners just Universal Patcher so I need to locate those tables first thing. Now I am questioning what I already did and thinking I should just start from scratch with the stock tune and go from there again.
It is easy to get so far in the weeds that starting over is best. I have done that multiple times on some builds. Here is a screenshot of your file opened to that offset table I referenced in hptuners, except this time in universal patcher.
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anybody want to chime in 
