FITECH Go-EFI 4
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FITECH Go-EFI 4
Goodmorning from S.Georgia,
1968 GMC K1500
406 SBC 9.5:1 N/A, Fitech EFI 960CFM injection
15.1" vacuum @ idle 700 rpm
TH350, No Stall, 3.42 gears (4x4 "K")
Edlebrock RPM Performer Heads/Air Gap Intake
Comp Cams XE262H, hydraulic lifters 1/2 past lash
HEI w/6AL CDI, 8mm Wires, Accel Header Plugs
Timing=14°@idle (25°vac/adv) 38° all in @2900
Unknown longtubes, Super 44s, 2.50" True Duals
4,000 miles on drivetrain/1,000 on Fitech System.
I am appealing to the EFI veterans and wizards out there with my question.
I really enjoy this new system and its capabilities. I am confident in the build and all its setting, as I had a perfect running engine with a carb, just with the typical carb inefficencies, cold start annoyances, endless tinkering, and the occasional load ups on a hot day with traffic stop and goes.
That being said, I am having a strange lean spike with minimal throttle engagement. Typically, under 17% as observed on my controller TPS monitor. My AFR lingers around 13.4 at idle, but with very light application of the throttle, will spike to 15.1-17.5. It is not an erroneous spike, because you will detect the vibrations of the engine shuttering from an overly lean condition, and if you open the throttle fast enough, not to exceed 17%, there will be a lean pop from the throttle body.
I have adjusted all AFRs, and Accel Pump settings to try and offset the lean condition, but nothing even begins to drop the spike down lower than 15.1.
Also, There is a 340 LPH pump feeding this system, and values do not drop off under this condition.
My troubleshooting has lead me to believe that, for whatever reason, the computer is waiting a split second under a "light load" to begin fuel delivery.
I am having no issues under WOT, kicking down a gear, or decel. Only under very modest acceleration.
If anyone understands what is causing this fuel starvation, between 700-1200 RPM and under 17% TPS opening....please let me know.
PS, I have contacted Fitech multiple times, and all they say is to increase Accel pump values. This is not working, but apparently that isnt an answer for thier customer support. Thats why Im here.
1968 GMC K1500
406 SBC 9.5:1 N/A, Fitech EFI 960CFM injection
15.1" vacuum @ idle 700 rpm
TH350, No Stall, 3.42 gears (4x4 "K")
Edlebrock RPM Performer Heads/Air Gap Intake
Comp Cams XE262H, hydraulic lifters 1/2 past lash
HEI w/6AL CDI, 8mm Wires, Accel Header Plugs
Timing=14°@idle (25°vac/adv) 38° all in @2900
Unknown longtubes, Super 44s, 2.50" True Duals
4,000 miles on drivetrain/1,000 on Fitech System.
I am appealing to the EFI veterans and wizards out there with my question.
I really enjoy this new system and its capabilities. I am confident in the build and all its setting, as I had a perfect running engine with a carb, just with the typical carb inefficencies, cold start annoyances, endless tinkering, and the occasional load ups on a hot day with traffic stop and goes.
That being said, I am having a strange lean spike with minimal throttle engagement. Typically, under 17% as observed on my controller TPS monitor. My AFR lingers around 13.4 at idle, but with very light application of the throttle, will spike to 15.1-17.5. It is not an erroneous spike, because you will detect the vibrations of the engine shuttering from an overly lean condition, and if you open the throttle fast enough, not to exceed 17%, there will be a lean pop from the throttle body.
I have adjusted all AFRs, and Accel Pump settings to try and offset the lean condition, but nothing even begins to drop the spike down lower than 15.1.
Also, There is a 340 LPH pump feeding this system, and values do not drop off under this condition.
My troubleshooting has lead me to believe that, for whatever reason, the computer is waiting a split second under a "light load" to begin fuel delivery.
I am having no issues under WOT, kicking down a gear, or decel. Only under very modest acceleration.
If anyone understands what is causing this fuel starvation, between 700-1200 RPM and under 17% TPS opening....please let me know.
PS, I have contacted Fitech multiple times, and all they say is to increase Accel pump values. This is not working, but apparently that isnt an answer for thier customer support. Thats why Im here.