Help with LS1 ECU triggering fuel pump

[VRSenator065]

Hi all. first post on here. I am running a standard LS1 ECU on my LSx454. I have an electric fuel pump that will flow a very high volume which is needed for max power but consequently is very loud at low throttle.

I also have an electronic controller that comes with the pump, that essentially runs the pump at a low flow rate, until its triggered then it switches to high flow. So for general regular during the pump can be nice and quiet then when needed switches to full flow when the increase in loudness doesn't matter.

The issue is how best to trigger it.

One way my auto electrician and I were discussing was if there was a way to sense the injector duty cycle. That way we could set it so that say if the duty cycle on the injectors went over 50% it would tell the pump to go full flow.

Does anybody with experience on an LS1 ECU know if this is possible, or have any other ideas or suggestions?

Thanks in advance.

[antus]

I believe similar functionality is already in the pcm, but I havnt messed with it. It seems the dual speed was implemented via PWM to the pump, and reading this comment, It sounds like if the pcm thinks its delivering over 60% torque then it'll run the pump at full speed.

Cleanest solution would be to use this functionality. I wonder if anyone here knows how it was implemented? is there any extra hardware?

[antus]

Another idea is to use the shift light functionality to supply the signal for your pump. According to this post at hptuners http://www.hptuners.com/forum/showthrea ... TRANS-ONLY!

today I added an Autometer "Shift-Lite" to my 2001 Camaro.

Normally you purchase "Pills" that are rated for a certain RPM(they are a certain Ohm resistance which correlates to a specific RPM for the light)

I went a slightly different route..

I made it an always on style light that comes on when you connect the ground by means of a "sink-to-ground" in the PCM

I took the Wires that the Pills normally connect to and connected them together so that there is no resistance...0 ohms = 0 rpm = always on

on the LS1 PCM, RED Connector, Pin #47 (On a Manual Transmission Only) is a sink to ground that is operated by a set of parameters in the PCM File(which can be set in the tune)

there is a wire for rpm on the light as well...for when you use the pills...
I connected it to the RED Connector Pin # 10 on the PCM because it is the RPM wire, so atleast it is seeing the RPM signal it is looking for.

In the tune you can command the shift light to come on by changing the values in the tables inside the red box in my image attachment below (this is from my 2001 Camaro..with a RTT OS...the table exists in all stock OS's as well..)

I cannot guarantee that this is the same on all PCM's... but it will work on any 99-02 LS1 based PCM with a Manual Transmission

do not attempt to do this on an automatic transmission vehicle, the pin 47 on an Auto is the control for the 2-3 shift solenoid

From reading this if you are running a manual trans I reckon you could set the shift light to the rpm you wanted the pump to go high speed and use the shift light output to control the hardware that came with the pump.

[VRSenator065]

Thanks for the replies so far, should clarify the car is Auto.

[Dylan]

What auto? Electronic shift or T400?

[VRSenator065]

Electronic, 4L65E

[VRSenator065]

Well spoke to my tuner and he suggested simply hooking it up to the ECU to come on at a certain rpm. I reckon that would be pretty nice way to do it, maybe I pick say 3000rpm, so I could drive it around on a light throttle opening and it would be nice and relatively quiet, and stay on the low setting, then once the revs hit 3000 it cuts in, that well and truly by 4 grand so so it's on full song. He suggested phone the auto elec could do that pretty simply. So will talk to him tomorrow.

[Apples]

Here is how Holden did it with the LS1 utes and used the same Module for supercharged V6.

LS1 UTE Fuel Pump Control.jpg

LS1 UTE Fuel Control Module.jpg

normally we bypass them but now with bigger noisy pumps its time to put it back