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Fitech EFI LS 750 issues

 
Old 05-14-2019, 08:15 PM
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Question Fitech EFI LS 750 issues

Engine info
I have a fitech 750 kit installed on my 69 camaro
Built 403ci Ls Twin turbo 68mm motor with WWCH stage 2 ported heads
81 pound injectors along with hyper fuel 1600 fuel pressure reg and 450gph in tank fuel pump
-8an supply and return lines
engine was dynoed with aem harness broken in already.
stock LS9 cam to a t56 magnum
idle set at 750
91 pump gas
Checked with smoke machine for vacuum leaks none of any kind intake exhaust or boost lines.
Fuel pressure is perfect 58psi
The issue
I'm having an issue with bogging with my fitech system at operating temps. I'll tap the gas from idle the car dies. If I barley press the gas pedal it'll be okay as long as i keep the rpms above 1k when coming from a dead stop. I only have 10-20 miles on the system. But this is getting annoying . Looking like a teenager stalling at every stop sign.

I've spend countless hours with their tech line can't seem to get this thing dialed in. Any info would be great!

log files provided
Attached Files
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Old 05-14-2019, 11:52 PM
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What air fuel ratio are you seeing before when it bogs? Can you tell if it's going lean or rich? I run Holley efi so I'm not familiar with the fitech setup or it's software, The Holley has a setting that "adds additional, momentary fuel based on the rate of change of the TPS. Same function as an accelerator pump on a carburetor".
If it's not getting enough fuel or to much when the throttle blades first start to open you'll get a stumble/bog.
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Old 05-28-2019, 01:16 AM
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I dont actually know "anything" about tuning yet. Just here learning. Got the fitech system on my mild 6.0l swap. I've just been researching tuning.

Just curious, I assume you have a boost/vacuum reference on your fuel regulator? Cause your small throttle crack, looks like the MAP hit atmospheric before rpm increase. And your fuel pw doubled. But the AF Learn dropped like 30% in a frame like it went to a different reference table. Stable 29 to 19, before the rpm climbs.

I dont have turbos. But I believe the boost feature on the fitech, has to be enabled. Did you select the power adder feature?

How long was that log time wise?
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Old 07-05-2019, 11:53 PM
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so... I have 70004 system on my LQ4 with decent cam.

Set your fast accel 170F @ 0
have you disabled your DFCO? or did you do any settings?
what is your IAC reading at idle in park? is it between 1-10?
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Old 07-06-2019, 12:00 AM
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Looking at your tables column F and G it shows your AFR is 10.4 ish from both O2 Sensors .. this should be 13.7-14.5 your very rich.

Your IAC setps is 61. that needs to be set between 1-10 your 51 high.


get that corrected and then i can help some more.
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Old 07-06-2019, 01:50 AM
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TPS and CPS tend to fail at high temps first, gradually getting worse..
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Old 07-06-2019, 06:24 AM
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when at temp.. what is your AFR driver side and AFR pass side showing? and at idle.. what is the IAC showing?
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Old 07-06-2019, 06:26 AM
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Originally Posted by pdxmotorhead View Post
TPS and CPS tend to fail at high temps first, gradually getting worse..
while at temp and idling... disconnect your TPS and let run for a few minutes. power down, then reconnect your TPS.
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Old 07-06-2019, 06:27 AM
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also, what MAP do you have 2 bar or 3 bar?
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Old 07-06-2019, 06:29 AM
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https://www.facebook.com/groups/959134994271169/


this is the fitech boosted page on facebook. 94 people there that has also with FI with fitech.
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