fuel pressure
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TECH Apprentice
Joined: Oct 2004
Posts: 361
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From: courps christi tx.
fuel pressure when i tuned my car for 30# injectors with hptuners i assumed fuel pressure was 58 psi but yesturday when i checked the pressure it was 65 psi. dose it matter should i load another tune with the correct pressure
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Joined: Aug 2005
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From: Sunny London, UK
Pressure can go fro 65 down to maybe 50 odd. It changes over the range of manifold pressures. To know exactly what it is you need to get a fuel pressure gauge etc.
So unless you have read pressure over the entire engine load range, then dont bet that its going to be 65 across all pressure readings, because it likely wont.
Or don't worry about it and tune your VE based on your current IFR table, it will change shape to suit. Not ideal, but most people don't have FP gauges for logging anyway so in effect they are doing this already.
So unless you have read pressure over the entire engine load range, then dont bet that its going to be 65 across all pressure readings, because it likely wont.
Or don't worry about it and tune your VE based on your current IFR table, it will change shape to suit. Not ideal, but most people don't have FP gauges for logging anyway so in effect they are doing this already.
Thread Starter
TECH Apprentice
Joined: Oct 2004
Posts: 361
Likes: 0
From: courps christi tx.
[QUOTE=ringram]Pressure can go fro 65 down to maybe 50 odd. It changes over the range of manifold pressures. To know exactly what it is you need to get a fuel pressure gauge etc.
So unless you have read pressure over the entire engine load range, then dont bet that its going to be 65 across all pressure readings, because it likely wont.
Or don't worry about it and tune your VE based on your current IFR table, it will change shape to suit. Not ideal, but most people don't have FP gauges for logging anyway so in effect they are doing this already.[/QUOT
i just checked the pressure with a guage at idle, but like you said i'm sure it dosent stay 65 across the board.i just did it because i was going to install a hot wire fuel pump kit and wanted to check pressure befor and after.
now about tuning VE and IFR i have no idea howto do it. i do have HPtuners but totaly suck at tunning. the only thing i know how to do is tune for injectors and even that took me a while. i have tried and tried to learn how to understand and tune my car but i just dont understand.
So unless you have read pressure over the entire engine load range, then dont bet that its going to be 65 across all pressure readings, because it likely wont.
Or don't worry about it and tune your VE based on your current IFR table, it will change shape to suit. Not ideal, but most people don't have FP gauges for logging anyway so in effect they are doing this already.[/QUOT
i just checked the pressure with a guage at idle, but like you said i'm sure it dosent stay 65 across the board.i just did it because i was going to install a hot wire fuel pump kit and wanted to check pressure befor and after.
now about tuning VE and IFR i have no idea howto do it. i do have HPtuners but totaly suck at tunning. the only thing i know how to do is tune for injectors and even that took me a while. i have tried and tried to learn how to understand and tune my car but i just dont understand.
