2018 SS, replaced low side pump to ZL1 setup and now have no hi side?

[vortech]

I'm having a very weird issue. 2018 SS Camaro. We swapped over to a Zl1 intank pump and conversion kit and now I am not getting any hi side pressure. Low side will climb but hi side will drop down to 1200psi.

Any idea what could be wrong?

TIA

[Kyle_Customizer]

What is the conversion kit? The ZL1 pump is a direct replacement for the SS. Did you change anything with the FPCM?

[Joshinator99]

I'm having a very weird issue. 2018 SS Camaro. We swapped over to a Zl1 intank pump and conversion kit and now I am not getting any hi side pressure. Low side will climb but hi side will drop down to 1200psi.

Any idea what could be wrong?

TIA

What other mods are done to the car? Just because the low side keeps up now doesn’t mean the high side will (adding a blower to a stock LT1 for example).

[vortech]

What other mods are done to the car? Just because the low side keeps up now doesn?t mean the high side will (adding a blower to a stock LT1 for example).

What's really weird is the this is a 18 A8 Camaro with Headers that we added a LT4 blower. Made 540/560 and called it a day. Now he came back and wanted to forge the motor so we forged it with GPI drop in rod and piston kit and thats where everything went wacky.

The other day I flashed and old tune back into the car and bang we have pump pressure again-but it will only go to 1800 psi or so. Before this it would maintain 2200. Now DC is 28% and injectors are 6.5 MS and its maxed. I don't know what would of caused the change?

[Joshinator99]

What's really weird is the this is a 18 A8 Camaro with Headers that we added a LT4 blower. Made 540/560 and called it a day. Now he came back and wanted to forge the motor so we forged it with GPI drop in rod and piston kit and thats where everything went wacky.

The other day I flashed and old tune back into the car and bang we have pump pressure again-but it will only go to 1800 psi or so. Before this it would maintain 2200. Now DC is 28% and injectors are 6.5 MS and its maxed. I don't know what would of caused the change?

Sounds like something is up with the HPFP. Is it still the LT1 HPFP or did you upgrade to the LT4? Did you put in a cam with a bigger fuel lobe? Be crazy to do the bottom end and not do the cam….

[vortech]

Sounds like something is up with the HPFP. Is it still the LT1 HPFP or did you upgrade to the LT4? Did you put in a cam with a bigger fuel lobe? Be crazy to do the bottom end and not do the cam?.

Yes still stock cam-this customer isn't looking for big power at all. I even swapped LT1 pumps. It's weird after a reflash the hi side started working but not like it used to. I just pulled the blower off to check the fuel lifter and it is fine as well as the fuel lobe. I put a lash cap on the fuel lifter now and check clearance and Im going to see if it brings up pressure.

[Jabercrombie]

What CC piston was used as the LT4 uses 18 cc . Did you ever get this fixed?