Help - LPFP Install Fail - Strange Issue

[Diggs24]

Gotta get in my dad jokes when I can.

 

[PacDawg]

We got some things in the works.

I think the controller is bullshit and we are going to try to bypass altogether. For now its pegged at 83/84% max but still don't know why it tripped a fuse .

It did sit and idled at first for like 20-25 minutes and apparently you're not supposed to do that with the 525s? Idk about that but why it blew at first is the real question.

I too don't want to spend the money on PM4 so my tuner was thinking of doing a hardwire mod on a Hobbs switch that only works above 15 psi. I'm too chicken to try it though.

 

[Diggs24]

I too don't want to spend the money on PM4 so my tuner was thinking of doing a hardwire mod on a Hobbs switch that only works above 15 psi. I'm too chicken to try it though.

Don't need one for the Tomioka, or are you upgrading?

 

[PacDawg]

Don't need one for the Tomioka, or are you upgrading?

Nope. So we can get full send boost on straight e85 with just mpi?

 

[Diggs24]

yes. added mpi last weekend.

 

[PacDawg]

yes. added mpi last weekend.

Nice. How much boost are you running. I'll order mpi soon after all this covid 19 shit blows over. My county has shelter in place so I can't work right now.

 

[Diggs24]

same as i was when it was warm out, 28psi. due to injection window limitations i had to turn it down to 25 psi on my e50 as it got cold out. got sick of blending and no way to see injector pulsewidth to guess what boost could be safely run. and pump gas was out of the question.

 

[neogeo]

What is the fuel pump speed “common error” that was mentioned in this thread? Sometimes I get a “fuel pump engine speed too low error”. Is this what was referred to? Can anyone here shed light on what this error means?

 

[Twist1]

Ok FML. Found cause of fuse blowing..

If i let the car sit and idle after a few minutes it attempts to literally max out rail pressure. No one can figure this out. We know it is 150% not a tune thing. The only variable is the 2018 controller looks different physically but has same part NO has previously 525 tuned mqbs. open to any ideas . Over time driving at light loads and idle the car just keeps creeping Low pressure fuel rail pressure. Like if i just leave it it attempts to go to the MAX allowed pressure the regulator allows. Itll sit there at 7.2k at idle! It wasn't doing this last night just all of a sudden started doing this when temps got a little warmer. We are beyond confuzzled at this point. Driving around light throttle it does the same thing, its just sitting pegged at like 6500-7k pressure which is wayyy too high. Its supposed to be 4500-5500. Pump speed doesnt get too crazy but the pressures just keep creeping up on me for literally no reason (no wot, no boost, no nothin).

I have a oem controller coming Im hoping somehow its the controller but this just doesnt make any damn sense!

 

[Diggs24]

What is the fuel pump speed “common error” that was mentioned in this thread? Sometimes I get a “fuel pump engine speed too low error”. Is this what was referred to? Can anyone here shed light on what this error means?

yes
not sure

 

[Twist1]

What is the fuel pump speed “common error” that was mentioned in this thread? Sometimes I get a “fuel pump engine speed too low error”. Is this what was referred to? Can anyone here shed light on what this error means?

These channels are not accessible through maestro. The PW from ecu to controller is not matching up to the drive speed of the pump (duh cause you just made it 20-30% bigger) so it trips a CEL.

It just needs to be coded out once car is 100% running perfectly but isnt something to super worry about.

However my issue is quite alarming as the car itself wont drive if it keeps doing this and could possibly start hurting hardware. Its basically running around with fuel rail pressures that are max WOT at idle and light load. So imagine its like doing a wot pull for 20 minutes straight. Lot of load on electrical and other components.

 

[Twist1]

Has anyone ever had this issue when installing 525? My rail pressure just keeps creeping up and up and up at idle and light load until finally thwyre literally at max regulated pressure 7200+ . They just slowly keep going up for no reason.

We're pretty sure this is what tripped fuse the first time. If I let it idle for more than a few minutes it just won't stop building insane amounts of pressure

 

[neogeo]

These channels are not accessible through maestro. The PW from ecu to controller is not matching up to the drive speed of the pump (duh cause you just made it 20-30% bigger) so it trips a CEL.

It just needs to be coded out once car is 100% running perfectly but isnt something to super worry about.

However my issue is quite alarming as the car itself wont drive if it keeps doing this and could possibly start hurting hardware. Its basically running around with fuel rail pressures that are max WOT at idle and light load. So imagine its like doing a wot pull for 20 minutes straight. Lot of load on electrical and other components.

Thank you for the explanation. So then this is a closed loop system — ECU adjusts PW based on volume it reads coming back from the pump and adjust until set point required for specific engine RPM is met.

I suppose even a PM4 can’t fix this then. Essentially a new mapping of flow rates to engine speeds are required for the higher volume pump. If I understand this correctly, that mapping is a probably a table in the VW firmware that can’t be replaced.

Our tunes would have scale this number down by the displacement factor before the ecu software (maybe a PID loop) makes its comparison... or code the light out for this specific error.

 

[daconchslop]

Has anyone ever had this issue when installing 525? My rail pressure just keeps creeping up and up and up at idle and light load until finally thwyre literally at max regulated pressure 7200+ . They just slowly keep going up for no reason.

We're pretty sure this is what tripped fuse the first time. If I let it idle for more than a few minutes it just won't stop building insane amounts of pressure

It sounds like you may need a FPR in line before the rail like PR sells with the Stg3+ kit? Or, echo- PM4

 

[JerseyDrew77]

Maybe a faulty 525?