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Failed LPFP or LPFP control module related fault codes

Vdub_enthusiast

Ready to race!
Hey guys just want some input on this topic. My car has been giving me extended cranking before starting for the past week. At idle vacuum was hanging around 19 instead of the normal 21-22 and it was running a bit rough. However, when coasting in gear vacuum held 22in hg no problem. So that brings me to this morning.... I went out to my car just to find the car would not start. 4 attempted cranks and no start. Haven't had a chance to scan it yet. But with the symptoms it was giving me all week before this I'm thinking either the lpfp or control module for the lpfp has failed. Any input would be greatly appreciated.

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NYCSuits

Go Kart Champion
What makes you think it's the LPFP rather than the HPFP?

The reason I ask is because the HPFP has a higher failure rate than the LPFP. When my HPFP went, my car would barely crank into life and I barely had any power in any gear. Felt like I was trying to accelerate in 6th gear all the time.
 

bigturbonyc

Ready to race!
Generally speaking the car will run(extended crank) with a bum hpfp, the lpfp will default to max pressure with no hpfp(6-6.5bar). If the lpfp and or module take a shit your car will not run. Extended cranks can be a bunch of things so I wouldn't just say that's your issue. An inch or two of vacuum is not something I would worry about.
 

Vdub_enthusiast

Ready to race!
Yes but the vacuum loss was associated with an obvious rough idle. So when I scan it tn when I get home if it's the hpfp should I more than likely be expecting a code for low fuel pressure at the rail?

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Vdub_enthusiast

Ready to race!
Thing is the past couple days when it's been giving me the long crank after it starts it runs great when upon acceleration. It was still pulling hard.

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FriggenT1

Banned
Yes but the vacuum loss was associated with an obvious rough idle. So when I scan it tn when I get home if it's the hpfp should I more than likely be expecting a code for low fuel pressure at the rail?

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I assume you've checked simple things like vac lines, etc. ?
 

MmmmmBoost

Ready to race!
When my lpfp went out it would stall under 30% or more load with less than a 1/4 of gas in it, you can test it out like that to confirm its the lpfp
 

mraaf

Passed Driver's Ed
P0087: Although detection is on high press side but it can be caused by failed low press pump or its module (J538)
P3073: I have this when using J538 to run a relay instead of LPFP directly. This is to avoid overloading when powering higher amps LPFP. No issue with this code tho.
P3045: When J538 is faulty
 

HYDE161

Go Kart Champion
P0087: Although detection is on high press side but it can be caused by failed low press pump or its module (J538)
P3073: I have this when using J538 to run a relay instead of LPFP directly. This is to avoid overloading when powering higher amps LPFP. No issue with this code tho.
P3045: When J538 is faulty

Does the P3073 code cause a lean spike for anyone when it occurs? I watched my AFR gauge spike to 16.8 when cruising, pulled over and scanned to find the one P3073 code....
 

VEE-DUBBER

Passed Driver's Ed
Does the P3073 code cause a lean spike for anyone when it occurs? I watched my AFR gauge spike to 16.8 when cruising, pulled over and scanned to find the one P3073 code....
It happens to me too and rail pressure dives. Pm3 with TTRS lpfp. Mine is most noticeable when going WOT. When the rail pressure drops it will pull timing. Some days it doesnt have any issues, and some days i can only just cruise to work and not have any fun.


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HYDE161

Go Kart Champion
It happens to me too and rail pressure dives. Pm3 with TTRS lpfp. Mine is most noticeable when going WOT. When the rail pressure drops it will pull timing. Some days it doesnt have any issues, and some days i can only just cruise to work and not have any fun.

Well this is scary, what software are you using? With Eurodyne are we able to turn off the actual P3073 code (set to class 0) but I'm not sure that prevents anything but the code popping up. I did talk to TB a while back and they said they were having an engineer look into the code for us. I circled back to Rick from TB who is extremely helpful.
 

VEE-DUBBER

Passed Driver's Ed
I am also using Maestro. I had sent TB the newest revision lpfp module that the pm3 wasn't playing nice with initially. The car would buck in boost. Swapped in my old original module from 09 and it cleared that up.

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HYDE161

Go Kart Champion
I am also using Maestro. I had sent TB the newest revision lpfp module that the pm3 wasn't playing nice with initially. The car would buck in boost. Swapped in my old original module from 09 and it cleared that up.

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In the driver's side dash fuse panel, did you change the 15a LPFP fuse to a 30a? I just coded out the P3073 code in ED and will flash my car this morning, coupled with the uprated 30a fuse I'll see if I run into any issues. I don't think I have the Chinese J538 module (starts with H as per TB) but I will check.
 

vwgti2.0t

Go Kart Champion
I find it hard to believe the HPFP has a bigger failure rate than the LPFP. I'm still using my stock OEM 120k mile HPFP and have been through 3 LPFP's...
 
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