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SOLVED - B230et LH2.4 rich on boost -

SOLVED - ISSUE WAS WITH THE FUEL PRESSURE REGULATOR OVER PRESSURISING AND CAUSING A RICH ON BOOST CONDITION.

After installing my AFR gauge I've noticed that she's very rich on boost. I also get a bit of a flat spot at the 4000rpm range when it goes to 10:1 or lower.

Changing boost pressure does nothing. I'm suspecting the injectors because of some other symptoms:

I get a misfire at idle and when I first start the car it runs rough and rich (like fuel has leaked onto cylinders) for about 7 seconds before clearing up. Suspecting the injectors may be leaking? I did have them cleaned and serviced before installation.

Another thing worth noting is that I'm using 850 t5 orange top injectors. Not sure what the flow rate of these injectors are?! The ones which came with the turbo motor were brown tops. Not sure of parts numbers either.

I have a new 02 sensor, knock sensor and coolant temp sensor.

Fuel pressure regulator is standard.

The maf sensor has been cleaned, could it be the culprit? It's the small one that ends in 016. Is it worth upgrading the maf to the 3inch type and would it be fine to use with the orange t5 injectors? I also have the white injectors from the v70 t5, but I didn't like how they sat in the manifold. They seemed too short, so i opted to use the orange tops.

Any help or direction would be appreciated.





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Comments

  • And AFR at idle is between 14.4 - 14.7 .
    Same AFRs at part throttle and cruising. Only rich when boosting.
  • Do you have a chipped ecu?
    ALVO360
  • Do you have a chipped ecu?

    I don't think so. Are All the turbo ecus chippable?
  • edited June 27
    I dont think all the ecus are chippable was just wondering.
    Are you seeing 10:1 @ wot and is there any difference at say 80% throttle
    Do you have an adjustable fuel reg?
    ALVO360
  • Standard regulator. I can get 10:1 with 30% throttle. Providing I'm still producing boost, it doesn't matter what revs or how much throttle is applied.

    I guess it could be a boost leak. I do have some seriously heavy duty clamps on brand new silicone hoses though.
  • Basically you either have to somehow get less fuel on boost or more air to lean it out, what size tb does it have?, maybe going to 3" will help your cause
    ALVO360
  • Oh the orange injectors are 315cc from memory and are the lowest of the T5 range
    ALVO360
  • Could be maf, think i have a spare you can try and i can also test the injectors for you if you want.
    ALVO360
  • Basically you either have to somehow get less fuel on boost or more air to lean it out, what size tb does it have?, maybe going to 3" will help your cause

    I just have the standard throttle body. Not sure of size. Is the 3" TB a bolt on upgrade? Would a 3inch maf work? Do you happen to know the flow rate of the brown top injectors from the 940 turbo?
  • Could be maf, think i have a spare you can try and i can also test the injectors for you if you want.

    Both of those would be great. I think I'll start with the maf and if it doesn't change anything I will definitely test the injectors.

    I actually need to drop an alternator to you for Matt @240 .

    Not sure when you can help out with the maf? I'm available tonight or I could head down to Ikes tomorrow between 12-2pm?

  • I'd start with injector leak test ($0), then the FPR.
    ALVO360
  • Basically you either have to somehow get less fuel on boost or more air to lean it out, what size tb does it have?, maybe going to 3" will help your cause

    I just have the standard throttle body. Not sure of size. Is the 3" TB a bolt on upgrade? Would a 3inch maf work? Do you happen to know the flow rate of the brown top injectors from the 940 turbo?

    Just thinking about it as I'm a P80 guy and not a redblock guy, I'm sure you have to run resistors on the orange injectors otherwise it will run mega rich, somebody cleverer than me in the redblock field will confirm but I'm pretty sure that will be the problem
  • Basically you either have to somehow get less fuel on boost or more air to lean it out, what size tb does it have?, maybe going to 3" will help your cause

    I just have the standard throttle body. Not sure of size. Is the 3" TB a bolt on upgrade? Would a 3inch maf work? Do you happen to know the flow rate of the brown top injectors from the 940 turbo?

    Just thinking about it as I'm a P80 guy and not a redblock guy, I'm sure you have to run resistors on the orange injectors otherwise it will run mega rich, somebody cleverer than me in the redblock field will confirm but I'm pretty sure that will be the problem

    I have a custom loom based on the late model 240's running lh2.4. I was told to use the t5 orange or white injectors as they were 'high impedence'(?). I assume the resistors were already intergrated into the new loom. Very interesting though.
    Jamest5r_
  • I'd start with injector leak test ($0), then the FPR.

    Why the FPR? My regulator is standard and cannot be adjusted. Are you thinking that maybe it's overpressurising? Do you know what the standard pressure should be for this regulator? I'd assume it's about 3bar?
  • Basically you either have to somehow get less fuel on boost or more air to lean it out, what size tb does it have?, maybe going to 3" will help your cause

    I just have the standard throttle body. Not sure of size. Is the 3" TB a bolt on upgrade? Would a 3inch maf work? Do you happen to know the flow rate of the brown top injectors from the 940 turbo?

    Just thinking about it as I'm a P80 guy and not a redblock guy, I'm sure you have to run resistors on the orange injectors otherwise it will run mega rich, somebody cleverer than me in the redblock field will confirm but I'm pretty sure that will be the problem

    I have a custom loom based on the late model 240's running lh2.4. I was told to use the t5 orange or white injectors as they were 'high impedence'(?). I assume the resistors were already intergrated into the new loom. Very interesting though.

    Ah ok, yes I would assume so, worth checking though
    ALVO360
  • Standard turbo fpr is 3bar n/a is 2.5
    If you want to swing past tomorrow fridays are usually pretty chilled and you can try the maf out.
    850 injectors dont need the resistor pack
    ALVO360
  • Standard turbo fpr is 3bar n/a is 2.5
    If you want to swing past tomorrow fridays are usually pretty chilled and you can try the maf out.
    850 injectors dont need the resistor pack

    Thanks Tim, I appreciate your help. I'll see you tomorrow.
  • And thanks @Jamest5r_ And @Roinik for you input, too.
    Jamest5r_
  • Hope you sort it, and post up the results I hate it when I don't find out the cause lol
    ALVO360egads
  • Hope you sort it, and post up the results I hate it when I don't find out the cause lol

    Same here. Even worse when it's a 4+ page post. I'll do us all proud, I promise.
    Jamest5r_egads
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