Logging variables for diagnosing possible HPFP issues

Seaneezy

Specialist
Mar 12, 2018
63
#1
Does anyone know how to differentiate between a failing lpfp or hpfp from log variables? I'm having misfires I think could be fuel related, the fuel pump shadow code is sticking, and the HPFP idrive message came up. The car has been pretty sluggish, especially on hills. I will have to get off and on the throttle until I can get a decent engine load where I can push power. I have to get an injector puller before I can see leaking injectors.
 
Sep 15, 2017
13
#2
I'm not sure what the variables are called for JB4, but if you're MHD log Fuel low pressure sensor and Rail pressure. I'd also log Load actual to help with diagnosing the HPFP. Low pressure should stay around 72 psi, but rail pressure varies because the ECU targets different values based on load. For some rough numbers, it looks like my car holds around 6-700 psi at low loads (up to 60ish load), and tapers up to 1500 psi at 90 load. Above that it jumps to 2000+ psi.

What fuel are you running? If it's on ethanol maybe try stepping down to pump gas to see if that helps things.
 

veer90

700HP Club (N54)
Nov 16, 2016
727
West Nyack, NY
#3
fuel low pressure (FP_L)
rail pressure (FP_H)
stft 1 and 2 (Trims and Trims2)
lambda bank 1 and 2 (AFR and AFR2)
load actual (Load)

and obviously everything boost related. also pull all codes
 

Seaneezy

Specialist
Mar 12, 2018
63
#4
took some logs this morning. Here's a cyl 5 misfire https://datazap.me/u/seaneezy/2719?log=1&data=2-8-13-19 . Rail pressure seems to keep up 2000+ psi and LPFP keeps around 82+ psi. Codes were 2AAE/F, the typical shadow codes except I still get the idrive notification. Ignore shit boost data, its my mmp inlets :tearsofjoy:
 

veer90

700HP Club (N54)
Nov 16, 2016
727
West Nyack, NY
#5
took some logs this morning. Here's a cyl 5 misfire https://datazap.me/u/seaneezy/2719?log=1&data=2-8-13-19 . Rail pressure seems to keep up 2000+ psi and LPFP keeps around 82+ psi. Codes were 2AAE/F, the typical shadow codes except I still get the idrive notification. Ignore shit boost data, its my mmp inlets :tearsofjoy:
I would say both hpfp and lpfp are healthy. what fuel?

The misfire is likely something else, when was the last time plugs / coils / injectors / walnut blast was done?
 

Seaneezy

Specialist
Mar 12, 2018
63
#6
I would say both hpfp and lpfp are healthy. what fuel?

The misfire is likely something else, when was the last time plugs / coils / injectors / walnut blast was done?
CA91 fuel. I'll pull the 5th plug to see if it's blown, I replaced them all less than 2 months/2k miles ago. 95776 gapped @ 0.22. Its the precision raceworks ignition system, I replaced the spark plug wires at the same time, not the coils. Valves are a little caked, could be cleaner (checked when plugs replaced). Injectors are the big mystery, I need to buy the puller tool (unless there is another way) to clean them and test leaks (attempting to start the car when injectors are out. I had a ton of o2 codes previously, but I have ar-dp c4tted d0wnp1pes so they shouldnt be there. Bought new post-cat o2 sensors they are on their way.

With my boost level/setup, is 0.22 the proper gap?
 

veer90

700HP Club (N54)
Nov 16, 2016
727
West Nyack, NY
#7
CA91 fuel. I'll pull the 5th plug to see if it's blown, I replaced them all less than 2 months/2k miles ago. 95776 gapped @ 0.22. Its the precision raceworks ignition system, I replaced the spark plug wires at the same time, not the coils. Valves are a little caked, could be cleaner (checked when plugs replaced). Injectors are the big mystery, I need to buy the puller tool (unless there is another way) to clean them and test leaks (attempting to start the car when injectors are out. I had a ton of o2 codes previously, but I have ar-dp c4tted d0wnp1pes so they shouldnt be there. Bought new post-cat o2 sensors they are on their way.

With my boost level/setup, is 0.22 the proper gap?
0.22 gap is fine with upgraded ignition, make sure wires are fully seated I know that's been an issue on PR kits.

injectors can be removed with channel locks or equivalent, some come right out by hand. depends on the level of corrosion, cylinder 6 is usually the worst. you can also make a diy puller tool
 

Seaneezy

Specialist
Mar 12, 2018
63
#8
0.22 gap is fine with upgraded ignition, make sure wires are fully seated I know that's been an issue on PR kits.

injectors can be removed with channel locks or equivalent, some come right out by hand. depends on the level of corrosion, cylinder 6 is usually the worst. you can also make a diy puller tool
I was just reading on alternatives to that $75 tool. I'll work something together and pull them out this weekend, I'm assuming I am going to be replacing at least one. For the valves, I'll pick up the gun and material for my air compressor and work through it soon, I need to activate my PI system after so I hopefully won't have to clean them for a while. I was thinking I had to spend $700 on a new HPFP, but since it looks healthy I have a lot of space for proper maintenance. I'll update this thread with an update. Thanks a ton!
 
Oct 3, 2018
34
#9
Be careful if you do it by hand, I pulled out my injectors by hand and knicked the tip on one of them. Didn't want to chance it, so I got all new ones. I recommend some sort of tool, diy or not.
 

Seaneezy

Specialist
Mar 12, 2018
63
#10
Be careful if you do it by hand, I pulled out my injectors by hand and knicked the tip on one of them. Didn't want to chance it, so I got all new ones. I recommend some sort of tool, diy or not.
Definitely gonna DIY it, $80 for a simple pull tool is insane. do you know the thread size of the injector caps? I don't think these have been pulled in a while, so there should be a ton of carbon buildup
 

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