Is there anything in the tune we need to update? I have an LT1 car and I copied the fuel pump data from a Z06. I'm not getting any extra high side fuel pressure. I tried another LT4 pump and it's the same thing. It's plugged in for sure but the fuel rail pressure is about the same as the low pressure side. We checked to make sure it's plugged in, the car ran fine with the LT1 stuff in it the day before. Can't be in the tune can it?
What all values did you change?
Make sure the axis is the same as the stock OS, I do change these from time to time, but you have to know what you’re doing or you’ll have problems
Email Tunes, [email protected]
96 TA Blown/Stroked, 4L80E/Fab 9
15 C7 A8 H/C 2.3 Blower/PI
14 Gen 5 Viper
Custom Mid Engine chassis, AKA GalBen C
Post tune.
2023 Ford Maverick 2.0T AWD
VIC.LT4.011.lt4fuelupgrade.hpt
So we updated everything we can find different under the fuel pump page. Axis has been updated as well. I was thinking maybe the lifter plunger that rides the cam needed to be changed with it? But I haven't seen anything about that anywhere and I'm pretty sure we've done this swap before.
Does the car have an aftermarket cam with 32% fuel lobe?
2023 Ford Maverick 2.0T AWD
Yes, we took the lash cap off being that it was an lt4 pump. We had one on when it was the LT1 pump
Needs the oem ls7 (.060) lash cap to function properly.Originally Posted by JASON11WS6
Last edited by HeavyChevy305; 01-14-2021 at 06:52 PM.
2023 Ford Maverick 2.0T AWD
Not necessarily. My lt4 hpfp measurements require no cap.
When I’ve used them I’ve used the ls7 which is shorter then some there were shearing the 2 HPFP bolts off!
I currently don’t have a lashcap on my personal lt4 Pump setup with 32% fuel lobe.. get my extra fuel from PI
Email Tunes, [email protected]
96 TA Blown/Stroked, 4L80E/Fab 9
15 C7 A8 H/C 2.3 Blower/PI
14 Gen 5 Viper
Custom Mid Engine chassis, AKA GalBen C
Tune looks okay?
So we put the LT1 pump back in with the LT1 tuning and it runs fine. Low side is a little out of steam but the rest looks good. Might just get a low side upgrade and go from there with the LT1 pump. Anyone look at my tune and make sure I didn't do anything that would have caused it to not work?
I ran in to this before with a 2014 model and Higgs Boson helped me so I am paying it forward.
On the 2014 only, you can NOT modify the High Pressure Pump/Peak Duration table when loading all the LT4 data, return it to stock and all will be well.
Ted.
Yup. Happened to me on a l83 Silverado when they switched to a LT4 fuel system.
2023 Ford Maverick 2.0T AWD
Exactly.
That, makes some sense. Thanks jannetty.
I just installed the DSX Low Side system on my 2017 Z06. Pump definitely works and turns on as soon Fuel Mode hits "High Flow". Now the low pressure looks great, it's the high pressure that's the problem. I'm running E30, just like I was before the added pump and high side would stay pretty close to the desired pressure under full throttle. Now the high side pressure drops to 1,000 psi (even 800 sometimes). AFR (Lambda) is constant at around 0.82 at full throttle even though the high side pressure is really low. I've only done limited runs on the street in 2nd and then in 4th gear. As soon as it goes into "High Flow" mode, the requested low side pressure jumps to 73 psi and the aux pumps turns on. Low side pressure jumps to 86 psi or so, confirming pump operation. At the same time high side pressure begins to drop. After 1.5s in High Flow mode, the high side pressure is right at 1,000psi and low side has dropped to 76 psi. That's as far as I went before letting off the gas (4th gear (auto), 5,000 rpm, 96 mph). Lambda solid at 0.83.
Has anyone seen similar results? High side pressure being that low is pretty scary, but at the same time AFR is still good.
PS - Injector Pulse Width is quite a bit higher than previously. It's up to 10-11 when the aux pump kicks on. Didn't change anything else, so this is a real mystery. Any help would be appreciated.
Your injector PW is about 2x higher then it should be
Email Tunes, [email protected]
96 TA Blown/Stroked, 4L80E/Fab 9
15 C7 A8 H/C 2.3 Blower/PI
14 Gen 5 Viper
Custom Mid Engine chassis, AKA GalBen C
Maintaining low side pressure is a requirement to support the high side pump.
BUT!!! it has almost no effect on high side being able to provide additional fuel volume required too support your build on E fuels, I suspect you are about 15 psi boost.
Any time high side drops injector opening time will increase.
Injector opening time is not related to low side pressure.
Ted.
Thanks for the replies. This is the funny thing. Without the low side pump, the PW and HPFP pressures are much closer to "normal". By normal I mean 5-6 PW and much closer to the requested 2,900 psi requested pressure. Nothing else has changed, other than the addition of the low side pump.
Reply With Quote