13.30s with super low rail press!
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i wonder if you got any bad fuel and your rail fittings are clogged...
have you tried commanding full pressure with the dvt's in efi? to see if your cp3 can make the pressure?
have you tried commanding full pressure with the dvt's in efi? to see if your cp3 can make the pressure?
LOL i told you to do this man, if you don't take our advice how can we help you? If you can flash a tune you can use the DVT function
how to use DVT function to test rail pressure:
open Scan Tool
turn truck on
connect to scan tool
look at the tabs it will say Console, OBD II, PIDs, Data, Dashboard, Maps, and DVT you could also just press F12
Now turn on the Activate button
Click on Desired Rail Pressure Control
where it says 40MPA increase that to 180MPA and if your truck goes to 26,000k then your CP3 is not bad.
You could also avoid ALL of this stuff my simply unplugging your Fuel Pressure Regulator connector like i said a week ago
open Scan Tool
turn truck on
connect to scan tool
look at the tabs it will say Console, OBD II, PIDs, Data, Dashboard, Maps, and DVT you could also just press F12
Now turn on the Activate button
Click on Desired Rail Pressure Control
where it says 40MPA increase that to 180MPA and if your truck goes to 26,000k then your CP3 is not bad.
You could also avoid ALL of this stuff my simply unplugging your Fuel Pressure Regulator connector like i said a week ago
Yea, i didnt have that step by step procedure!
Honestly ive been pretty lazy about further diagnosis, eventually ill try the dvt thing but i have kinda lost all motivation right now. 
Thx for posting that Paint!!!!! Now I know how to test the cp3! Looks simple written down .:thumb:
x2. I shimmed mine years ago and still had some rail pressure issues. Put in a race valve and I couldnt beleive the difference.
So what shouhld be expected, is it alright to be a few thousand shy,(26,000vs24,000), or should it be alot closer? If the pressure isn't there, will the timing stay the same, and be early? If enough fuel is not there, can the lack of fuel wreck a motor due to over advanced timing?
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This is great info, thanks paint :thumb:
Book marking this so I can check a few things when I get home.
nick is that test really accurate? it seems to me like it would be quite easy to build 180mpa with the truck at idle. much harder with a fuel command though
just thinking outloud
nick is that test really accurate? it seems to me like it would be quite easy to build 180mpa with the truck at idle. much harder with a fuel command though
just thinking outloud
I know I just talked to a GM tech and he told me the beginning of an injector test starts out with this. They comand 160MPA and if the rail goes below 158MPA then they will continue with the rest of the tests.
nick is that test really accurate? it seems to me like it would be quite easy to build 180mpa with the truck at idle. much harder with a fuel command though
just thinking outloud
If you have a rail issue it will show most times with that test , when i had bad injectors I could only build 22k at idle with Dual Cp3's
, minor issue's it may not spot but it is def work checking , it only takes 5 min and could tell you alot .
10-4 thanks. you can use the dvt tool while logging right? ive only played with it a few times
ya , at least i have on rail pressure.
have you replaced your fpr or modded it? it looks cranky.. too high when you command low and too low when you command high.