2019 L87 6.2 Silverado with LT4 injectors/pump

[JASON11WS6]

Just put in a set of LT4 injectors and a LT4 high side pump into an L87 6.2 2019 Silverado. Started it up and it's not running right. Anyone else do this swap? We do it all the time on LT1 cars and I just copy the data for the injectors and pump. With the exception of the 2014s pump data it's straight forward. Any tricks on these?

[Camaro6]

Just put in a set of LT4 injectors and a LT4 high side pump into an L87 6.2 2019 Silverado. Started it up and it's not running right. Anyone else do this swap? We do it all the time on LT1 cars and I just copy the data for the injectors and pump. With the exception of the 2014s pump data it's straight forward. Any tricks on these?

2019 has a different fuel pressure sensor pretty sure. I had that come up from a local shop that reached out to me after doing a LT4 fueling swap. What is you High Pressure Fuel Pump (HPFP) reading when running? Low Side? Do you have a log & tune to be reviewed?

[JASON11WS6]

Yeah it's running 3k psi at idle lol. I'm guessing I'll need to make some tweaks

[Dominatorstang]

I noticed the pump on a L87 is a different PN than L86 and am curious if they are a direct interchange. Can you share your stock ECM file so I can compare to stock L86 file fuel tables? I ask because I may have an issue with my pump and have access to a used L87 replacement.

[JASON11WS6]

They bolt right up but you do need a new harness part 12689504 (all 2019s and up). It runs from the injectors to the pump I think. The files are mainly the same but when I switched everything over I was running 3k pressure at idle. So I just made some sensible changes to the main pressure map

[Dominatorstang]

Good to know. Thank you!

[GR8GAME]

Was a solution found to this? We have a 2022 L87 switched over to an LT4 pump and it keeps throwing a code then bypassing the high pressure pump, bringing the rail pressure down to 60-70psi

[GR8GAME]

FYI apparently the L87 computer needs to see a different ohm range than the lt1/lt4/l83/l86 variations do. First pump we put in ohm'd @ .9, where the L87 ECM needs to see 1.0-1.7? LT4 pumps supposedly range from .9-1.4..

Still looking for a solution. Ideally, we'd be able to change the ECM to be able to recognize a different range. Any ideas are welcome.

[Eng.LSX]

Any one ran into this also? I guess it should be the same for C8's.

[Jeffnrivercity]

FYI apparently the L87 computer needs to see a different ohm range than the lt1/lt4/l83/l86 variations do. First pump we put in ohm'd @ .9, where the L87 ECM needs to see 1.0-1.7? LT4 pumps supposedly range from .9-1.4..

Still looking for a solution. Ideally, we'd be able to change the ECM to be able to recognize a different range. Any ideas are welcome.

Any movement on this?...we dropped a LT4 with a 2.9l whipple in a 2020 gmc 1500, and had to run the the stock L87 HPFP to get it to run

[GHuggins]

I posted the correction for this in another thread. Thought it was this one, but obviously not. These newer ones are sensitive to their ohm reading of the hpfp's control regulator. I think Dave said there were 3 different ranges that they are programmed or calibrated to. Simple solution is to remove the control regulator from the original one then install that into the LT4's.

I should also note that the injector data has changed for the LT4 injectors for the newer platforms. The LT5's use the same pumps and injectors FWIW and have the newer data.

[thegainsdepartment]

Link to thread?

[Jeffnrivercity]

I posted the correction for this in another thread. Thought it was this one, but obviously not. These newer ones are sensitive to their ohm reading of the hpfp's control regulator. I think Dave said there were 3 different ranges that they are programmed or calibrated to. Simple solution is to remove the control regulator from the original one then install that into the LT4's.

I should also note that the injector data has changed for the LT4 injectors for the newer platforms. The LT5's use the same pumps and injectors FWIW and have the newer data.

That sounds like an easy fix, Is it hard to switch the regulator?..more info lease

Thx Jeff

[GHuggins]

I haven't done one in person. Also couldn't find the thread for you. It was a thread associated to a dtc the more I think about it. My customers don't seem to have any issues swapping the regulator then everything is fine after that. No more codes or problems.

[bonecrrusher]

I haven't done one in person. Also couldn't find the thread for you. It was a thread associated to a dtc the more I think about it. My customers don't seem to have any issues swapping the regulator then everything is fine after that. No more codes or problems.

Do you think the 2022+ Global B - that regulator swap would work?

I got a 22.5 Refresh ZR2 I'd like to add an LT4 too.

[GHuggins]

Do you think the 2022+ Global B - that regulator swap would work?

I got a 22.5 Refresh ZR2 I'd like to add an LT4 too.

It should. So far it's working on all global A's. You just have to make sure to change the pump tables to an lt4's. You also don't have to worry about adapter harness's then either.