L5p tune has got me p0087 code

[Qmaqma]

Speed lab delete kit. Everything went great on this delete. Installed bus connectors all seated and checked continuity through connector as was told to because of the cheap connectors. Have a p0087 code. Truck was running fine before delete.
On scanner I see desired fuel pressure go up but actual stays the same. Runs like crap

 

[Bdsankey]

P0087 is a low rail pressure code. If you used their tuning I'd be inclined to say buying straight from China didn't help on this one since you didn't touch the high pressure fuel system.

 

[Ron Nielson]

Which modules were bypassed with the bus connectors? Might the bypassed modules be causing your problem?

 

[gmduramax]

P0087 is a low rail pressure code. If you used their tuning I'd be inclined to say buying straight from China didn't help on this one since you didn't touch the high pressure fuel system.

If desired is going up but actual isn’t wouldn’t that indicate there’s a problem with the truck?

A lot of times I see people with old batteries that refuse to replace them because the truck starts day to day but leaving the key on while flashing is enough to drain them and cause all kinds of weird issues.

 

[Bdsankey]

If desired is going up but actual isn’t wouldn’t that indicate there’s a problem with the truck?

A lot of times I see people with old batteries that refuse to replace them because the truck starts day to day but leaving the key on while flashing is enough to drain them and cause all kinds of weird issues.

The hard part for me is "what changed"? There's nothing that gets undone that would cause a P0087 and that type of failure doesn't always indicate a hard part problem.


If the reg tables are garbage in the file it'll also cause this issue where the truck is demanding pressure rise but not commanding the reg to move. This is super common on earlier trucks where say it hits a limit in the current table etc.


A data log would answer most of these questions.

 

[gmduramax]

The hard part for me is "what changed"? There's nothing that gets undone that would cause a P0087 and that type of failure doesn't always indicate a hard part problem.


If the reg tables are garbage in the file it'll also cause this issue where the truck is demanding pressure rise but not commanding the reg to move. This is super common on earlier trucks where say it hits a limit in the current table etc.


A data log would answer most of these questions.

100% I forgot about reg tables

 

[Bdsankey]

100% I forgot about reg tables

I've seen similar issues on SPE Lab files. Guys buy them because they're cheap then they complain they have to buy tuning twice.....................

I haven't seen a P0087 but based on the other issues I've diagnosed with customers it wouldn't surprise me. I've seen SPE Lab jam in the wrong OS/segments and cause so many issues.

 

[Qmaqma]

P0087 is a low rail pressure code. If you used their tuning I'd be inclined to say buying straight from China didn't help on this one since you didn't touch the high pressure fuel system.

Correct did not touch high side fuel anything. Checked continuity through the bus connectors through the plug and have continuity through the plug.

 

[Qmaqma]

100% I forgot about reg tables

These codes show in ezlynk. But do not show on my snap on scanner.

 

[Qmaqma]

Which modules were bypassed with the bus connectors? Might the bypassed modules be causing your problem?

Nox sensor on frame and the one on top of driver side valve cover. And ybridge over by def tank

 

[Qmaqma]

If desired is going up but actual isn’t wouldn’t that indicate there’s a problem with the truck?

A lot of times I see people with old batteries that refuse to replace them because the truck starts day to day but leaving the key on while flashing is enough to drain them and cause all kinds of weird issues.

Batteries are fully charged and good shape.

 

[Chevy1925]

Engine off, key on, clear the codes and see what comes right back. If the p0193 comes back, I’d be chasing sensor 5 volt reference issue. Not the low fuel pressure

 

[Qmaqma]

Engine off, key on, clear the codes and see what comes right back. If the p0193 comes back, I’d be chasing sensor 5 volt reference issue. Not the low fuel pressure

 

[Bdsankey]

Can you clear the codes and see what comes back per the request made by James?

 

[Qmaqma]

Can you clear the codes and see what comes back per the request made by James?

 

[Bdsankey]

If you meant to post a picture or text, nothing came through.