LTFT at 25 with 39# Cobra Injectors
LTFT at 25 with 39# Cobra Injectors I installed some 39# blue tops yesterday, edited the IFR, and now my LTFTs are at 25 and I'm throwing lean codes.
I used the injector spreadsheet from HPTuners to obtain the values for my IFR. I first assumed that the injectors are rated 39# at 39.15psi, then changed the IFR values for 39# at 3 bar. Both IFR table values gave me high LTFTs.
I added 25 to the main VE table, but the LTFTs settled back to 25. Just for kicks, I took 25 out of the VE and I got the same result.
I see normal LTFTs with the stock injectors and IFR table, but the blue tops throw them out of whack. I'm going to check my rail pressure just to make sure something isn't wrong there.
Is there anything else that I need to address in the fuel control for these injectors (PW etc.)?
Here are the IFR tables I am using.
0-80kPa
39# at 39 psi
46.94 47.25 47.56 47.81 48.12 48.43 48.67 48.98 49.23 49.54 49.79 50.1 50.35 50.66 50.91 51.15 51.46
39# at 43.5 psi
45.02 45.33 45.57 45.88 46.13 46.44 46.69 46.94 47.25 47.5 47.74 48.05 48.3 48.55 48.8 49.05 49.36
I used the injector spreadsheet from HPTuners to obtain the values for my IFR. I first assumed that the injectors are rated 39# at 39.15psi, then changed the IFR values for 39# at 3 bar. Both IFR table values gave me high LTFTs.
I added 25 to the main VE table, but the LTFTs settled back to 25. Just for kicks, I took 25 out of the VE and I got the same result.
I see normal LTFTs with the stock injectors and IFR table, but the blue tops throw them out of whack. I'm going to check my rail pressure just to make sure something isn't wrong there.
Is there anything else that I need to address in the fuel control for these injectors (PW etc.)?
Here are the IFR tables I am using.
0-80kPa
39# at 39 psi
46.94 47.25 47.56 47.81 48.12 48.43 48.67 48.98 49.23 49.54 49.79 50.1 50.35 50.66 50.91 51.15 51.46
39# at 43.5 psi
45.02 45.33 45.57 45.88 46.13 46.44 46.69 46.94 47.25 47.5 47.74 48.05 48.3 48.55 48.8 49.05 49.36
I just checked my fuel pressure and it's 58psi dead nuts.
I sprayed for vacuum leaks and found none.
I also set my IFR to the stock 28# injector slope and the trims went way negative with the 39# injectors installed, as expected.
Anyone have any ideas?
I sprayed for vacuum leaks and found none.
I also set my IFR to the stock 28# injector slope and the trims went way negative with the 39# injectors installed, as expected.
Anyone have any ideas?
Last edited by Silver02Z28; May 9, 2007 at 05:32 PM.
I'm also interested in this! Someone with some experience on these injectors please chime in with the IFR table that worked for you. I just set these up on a buddys car but he has yet to drive it (waiting on suspension parts). I'd like to start with a table that is close.
Nick
Nick
I think it has been resolved.
https://ls1tech.com/forums/pcm-diagnostics-tuning/711580-high-ltfts-cobra-blue-tops.html
https://ls1tech.com/forums/pcm-diagnostics-tuning/711580-high-ltfts-cobra-blue-tops.html
