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Discussion Starter #1
Hi guys,I have a problem with fuel pressure, in my beast there are two aem pumps 340 L/H new fuel filter and still low pressure, when we clear all error codes it goes crazy but after 10 minutes the pressure goes down again,my minds about ekp, any advices?
 

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Was this happening before the new fuel pumps? Why the change to AEM? Have you actually measured the fuel pressure? What are the codes you're clearing tell you? Is the fuel pressure regulator messed up?



Give us some more info.
 

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Discussion Starter #3
It starts after fuel filter was changed,but all connections in tank are without liking,27cf, multiple misfire and empty tank in the entry, aem pumps was fitted because of gintani supercharger kit
 

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Fuses F30, F72.

If those are good, the EKP. The MOSFETs in the EKP weren't designed to drive pumps with larger current draw. They occasionally fail in the OEM configuration.
 

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The only way you will get the solution is if you talk to Alex. Running those pumps without changing programming in fuel pump module is never going to work. I have seen many try to fit these pumps with an existing fuel filter/regulator and the car start tripping out first time you go over 6500

Sent from my SM-G950U using Tapatalk
 

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Discussion Starter #11
We check the voltage in ekp and it drops to zero on high rpm for second, decide to change the pumps side to side, and no limp mode and voltage is ok now) order two new pumps
 

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Discussion Starter #12
Install new pumps,and still the same problem))) badly rpm 2500-3000, misfire 9cylinder and 6, sometimes 3 and 2,any ideas guys?)
 

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@Gintani777 did you found where the issue was coming from?

Fuses F30, F72.

If those are good, the EKP. The MOSFETs in the EKP weren't designed to drive pumps with larger current draw. They occasionally fail in the OEM configuration.
@jcolley Is there a way to test the Mosfets (or the EKP) before unwelding everything?



I have the same fuel pressure problem since last week, I can drive soft without any issue, but at high rpm the management light comes on and I get 'engine fault reduced power

Here is what I've changed recently (before the issue happened):
New AEM 340L fuel pump (last year / 10k km ago)
New fuel filter + fuel regulator (2 months / 2000km ago)

I've ran ISTA, reseted adaptation, ran the fuel pressure test :


  • fuel pressure before start is good 5.8bar (should be between 5.2-6.6bar)
  • fuel pressure at idle is too high, it drops at 2.9bars just after starting the engine which is good (should be between 2.9-3.1bar at IDLE, but then increase up to 3.8 bars
  • fuel pressure at high rpm is too low : 4bar max (should be 5.5 bar min I believe)
Even when I reset the adaptation and clear the error codes, the engine fault come back as soon as I go high rpm


Any help is much appreciated
 

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@Gintani777 did you found where the issue was coming from?



@jcolley Is there a way to test the Mosfets (or the EKP) before unwelding everything?



I have the same fuel pressure problem since last week, I can drive soft without any issue, but at high rpm the management light comes on and I get 'engine fault reduced power

Here is what I've changed recently (before the issue happened):
New AEM 340L fuel pump (last year / 10k km ago)
New fuel filter + fuel regulator (2 months / 2000km ago)

I've ran ISTA, reseted adaptation, ran the fuel pressure test :


  • fuel pressure before start is good 5.8bar (should be between 5.2-6.6bar)
  • fuel pressure at idle is too high, it drops at 2.9bars just after starting the engine which is good (should be between 2.9-3.1bar at IDLE, but then increase up to 3.8 bars
  • fuel pressure at high rpm is too low : 4bar max (should be 5.5 bar min I believe)
Even when I reset the adaptation and clear the error codes, the engine fault come back as soon as I go high rpm


Any help is much appreciated
Also, I'm not sure if or how this is related, but I have an issue with the fuel level:

When I idle for about 1min, the fuel level drops of about 1/2 tank. The tank driver side seems to be full of fuel. but once I shut down the engine I can hear and see the fuel level droping from the driver side and gauge is moving back to full.


I assume there's an issue with the return line, but I'm not sure how this is related with the high pressure issue
 

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Interesting video. I know that there are 2 pumps, one is a transfer pump to kicks on to move fuel from the driver to passenger side. The other pump is the one is on the passenger side that feeds the filter module which then goes to the output line, all on the driver side. For some reason your transfer pump is on pumping at max rate, when the car shuts off, it drains back. It may be the fuel level float on the passenger side being broken commanding the transfer pump to turn on.
Or when you rewired up the pumps or whatever mod you did you effed something up.
 

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I use my extra tank as a big gas container and manually control the pumps with 12v to pump out the gas. I don’t fully understand how the EKP controls them, I can’t get them to empty more than 80% on controlling the pumps manually with 12v. There is some additional logic, based on each side’s level on when to operate the transfer pump.
 
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