DIY 335IX built motor/trans single turbo build
- Thread starter nyt
- Start date
Changed out the wastegate springs tonight, that's never fun, but the speedtech kit made it doable without much frustration.
I have a low pressure fuel issue. Not sure what it is. I need to hook up a meter to the second fuel pump and see if its kicking on or what.
This is with an external regulator. It peaks at 89 then drops to 70...
I'm going to check to make sure my second pump is kicking on. If so, perhaps fuel filter is mucked up.
Once that's sorted, I'll start doing some knock tweaking, false knock all over w/ closed deck and forged pistons.
I have a low pressure fuel issue. Not sure what it is. I need to hook up a meter to the second fuel pump and see if its kicking on or what.
This is with an external regulator. It peaks at 89 then drops to 70...
I'm going to check to make sure my second pump is kicking on. If so, perhaps fuel filter is mucked up.
Once that's sorted, I'll start doing some knock tweaking, false knock all over w/ closed deck and forged pistons.
Wow, stripped the cap of my fpr. An entire two threads in aluminum. Deatschwerks sure built that unit with robustness in mind. Need to get a replacement for that or modify it so that it's a bit more stout.
I think I'll be making some fuel system changes as well in the near term.
1) route secondary pump via dedicated line to a tee
2) route primary pump via the cap on the driver side so the venturi still works, but skip the fuel filter, run this to the tee
3) add a filter after the tee and connect this up to to the Y in place between the HPFP And PI injectors.
Still thinking on this, not sure yet.
I think I'll be making some fuel system changes as well in the near term.
1) route secondary pump via dedicated line to a tee
2) route primary pump via the cap on the driver side so the venturi still works, but skip the fuel filter, run this to the tee
3) add a filter after the tee and connect this up to to the Y in place between the HPFP And PI injectors.
Still thinking on this, not sure yet.
I installed these last summer and they definitely tightened up the front end on my 335xi.
So I managed to fix my FPR last night. Not my prettiest work, but it'll do, and it shouldn't strip out so easily again. I added about a cm of material on top and tapped it.
I was going to do some tests tonight but it started raining, so I didn't get to.
Something strange is going on. I set my FPR to 80psi, no pressure reference. When I trigger the fuel pump to run flat out it hits 80psi, no issue there.
However, under boost, it hits 80psi after the JB4 kicks on the second pump, then falls back down to 70...
I'm targeting 5525 hectopascals which is just over 80psi, so it shouldn't be DME/EKP related, never mind that the second pump is driven off of a relay and running flat out.
I'm about to just say screw it and redo the low pressure fuel system. Perhaps the filter is causing some significant restriction.
I was going to do some tests tonight but it started raining, so I didn't get to.
Something strange is going on. I set my FPR to 80psi, no pressure reference. When I trigger the fuel pump to run flat out it hits 80psi, no issue there.
However, under boost, it hits 80psi after the JB4 kicks on the second pump, then falls back down to 70...
I'm targeting 5525 hectopascals which is just over 80psi, so it shouldn't be DME/EKP related, never mind that the second pump is driven off of a relay and running flat out.
I'm about to just say screw it and redo the low pressure fuel system. Perhaps the filter is causing some significant restriction.
I would try running a reference to the regulator first ! Because the regulator is bleeding some (fuel) back to the tank its possible for this flow to increase with boost , remember when you set the static pressure its with no pressure in the manifold, under boost the flow will go back to the tank as it is the path of least resistance, you need the reference to cause the regulator to throttle that flow and force it forward to the injectors.
I had a reference on it, but the DME expects a static pressure, hence why I set it to 80psi and updated the map for that. Otherwise, DME will try to reduce duty cycle. It drops the same even w/ a reference.
Just got back from traveling. I've hooked up the JB4 antilag output to the IAT connector again. I had to make a new wire with some reinforcement this time. Hopefully with the new firmware it reacts faster than last time, which is why I disconnected it. Added some quick disconnects in case I'm not happy with it.
I also replaced a potentially faulty adv o2 sensor, will see how that goes.
While I was traveling, a BPM4 got delivered, so that's going in asap, then I can actually log the DME fuel requests sent to the EKP.
I also replaced a potentially faulty adv o2 sensor, will see how that goes.
While I was traveling, a BPM4 got delivered, so that's going in asap, then I can actually log the DME fuel requests sent to the EKP.
Ok, so I probably didn't need the BPM4, but it will be useful in the future if I upgrade pumps, and is immensely useful for some datalogging of the dme fuel request.
I have some kind of fuel restriction to deal with, likely the stock venturi and filter. My fuel pressure is dropping to 60psi with the regulator set at 80 and two 450HP pumps at full output.
There's also the strange issues I'm seeing with bank 1 going lean at the top of the pull. It's not the O2 sensor, as I've just replaced it to be sure. Perhaps an injector issue, though I also saw the HPFP drop at the same time. I may have to pull things apart and swap injectors around and see if it follows. What a headache. I may try to address the low pressure side of things first. I'm really not thrilled with any of the options on the market at the moment.
Then there's the weird boost drop around 6000 rpm with no indication as to why. Perhaps related to the fueling issue as AFRs went a bit lean right after.
And the BPM4 log
I have some kind of fuel restriction to deal with, likely the stock venturi and filter. My fuel pressure is dropping to 60psi with the regulator set at 80 and two 450HP pumps at full output.
There's also the strange issues I'm seeing with bank 1 going lean at the top of the pull. It's not the O2 sensor, as I've just replaced it to be sure. Perhaps an injector issue, though I also saw the HPFP drop at the same time. I may have to pull things apart and swap injectors around and see if it follows. What a headache. I may try to address the low pressure side of things first. I'm really not thrilled with any of the options on the market at the moment.
Then there's the weird boost drop around 6000 rpm with no indication as to why. Perhaps related to the fueling issue as AFRs went a bit lean right after.
And the BPM4 log
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