Issue with sudden Timing drop - log included

[Silent11]

Im having this issue where timing drops for a second and then comes back. Any clues to what would cause this ?

2007 E92 335i / VRSF 7.5 Race FMIC-Charge Pipe-DCI-Inlets/ TurboSmart Plumb Back DV / XHP / E50 Custom Tune by WedgePerformance / APEX ARC8 / MT ET Street / 11.4 @ 120 / Instagram @silent11n54

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[martymil]

Looks like your Rail pressure is tanking so the ecu pulled timing out to help it recover.

You either have a boost leak or one of the boost solenoids is stuffed or turbos are just tired as your wgdc is just maxed up top.

Turbos wont last long running them like that.

 

[Silent11]

ive had the same tune for a while now ( almost a year ) and my rail was always tanking like that but it never cut timing. new hpfp but still on index 1 injectors with 130.000 miles wgdc was always maxed out, turbos are tired for sure i thought maybe since it overboosted a little it cut timing . I replaced a boost solenoid recently since it started humming loudly.

 

[martymil]

did you replace both boost solenoids ? these should be done in pairs.

did you check vacuum lines ?

Those turbos are not long for this world at that wgdc.

There are so many different things the ecu can cut timing for but judging by that log its got something to do with fuel pressure look at your lpfp it tanks along side your hpfp, it cuts timing and they both recover quickly

Fix your lpfp from tanking and the hpfp won't tank so badly, have you removed the filter inside your hpfp ?

I just done a car about 3 weeks ago with the same problem doing the exact same thing.

We upgraded the hard line and removed the filter from the hpfp and now he gets steady 1500psi on his rail and no timing drops

 

[Silent11]

since i installed the walbro 525 weird things are happening.... it will hover around 72-73 psi and i will do a pull , after that it will hover around 82-83psi until i shut it off. if i do another pull while its around 82-83psi it wont go below 65psi. i never replaced the hpfp sensor when i installed the new hpfp so maybe ill remove the filter and change the sensor while im there. I also never replaced the lpfp sensor.

 

[doublespaces]

Do you have PI? I guess you're on stock turbos so maybe not, but your STFT is kind of odd, there is a decent delta between them which can indicate a leaky injector but I don't see it in your AFR. Does your car stumble on cold start at all?

How are you triggering the 525, just off the stock EKP or do you run two pumps?

 

[Silent11]

Do you have PI? I guess you're on stock turbos so maybe not, but your STFT is kind of odd, there is a decent delta between them which can indicate a leaky injector but I don't see it in your AFR. Does your car stumble on cold start at all?

How are you triggering the 525, just off the stock EKP or do you run two pumps?

no pi, still index1s with 130.000 miles, it did stumble at cold start until i changed the hpfp, no issues since. stock ekp, ekp2 is around 72psi and ekp3 idles at 85psi so i went back to ekp2

 

[doublespaces]

Well, first of all your HPFP shouldn't do that. I've also learned just because the LPFP is above 50, doesn't mean its doing it's job. The sampling resolution on these cars isn't very good, not to mention any unknown factors, I'd definitely try to address that, because it is abnormal.

With that aside, the timing is a bit interesting, but its 1 degree. Who cares IMO.

 

[langsbr]

With that aside, the timing is a bit interesting, but its 1 degree. Who cares IMO.

I'm on my phone so it's hard to see but it looks like he's dropping from 14* to -8*. It might only be for a moment, but I'd be more concerned about the drop and then spike right back up.

 

[martymil]

since i installed the walbro 525 weird things are happening.... it will hover around 72-73 psi and i will do a pull , after that it will hover around 82-83psi until i shut it off. if i do another pull while its around 82-83psi it wont go below 65psi. i never replaced the hpfp sensor when i installed the new hpfp so maybe ill remove the filter and change the sensor while im there. I also never replaced the lpfp sensor.

Nothing wrong with your lpfp and your hpfp sensors

Most likely the 525 is pulling to much current and is overheating your ekp causing it to do weird things.

 

[doublespaces]

I'm on my phone so it's hard to see but it looks like he's dropping from 14* to -8*. It might only be for a moment, but I'd be more concerned about the drop and then spike right back up.

Yeah I was only looking at correction.

So what is causing the timing to skip around that timing table like that? Doesn't that appear as a correction if it isn't what the tune asks for? Is it a rpm or load table or what? Sorry, not a tuner.

 

[langsbr]

Looking at the graph from my PC I'm less concerned about it because it didn't occur until after the pedal was lifted.

@Silent11 does it happen if you stay in it and let it shift?

 

[Silent11]

Looking at the graph from my PC I'm less concerned about it because it didn't occur until after the pedal was lifted.

@Silent11 does it happen if you stay in it and let it shift?

here is a 3-4 log ... this was with the lpfp at 83psi at idle

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[doublespaces]

Why are you lifting the pedal? Orange trace.

 

[Silent11]

Why are you lifting the pedal? Orange trace.
View attachment 36800

probably a bump in the road so i didnt stay in it 100%

 

[langsbr]

That slight lift shouldn't matter since throttle position didn't drop. I forget the mapping but something like 60% pedal is 100% throttle.

Could that timing pull be related to xhp? I'm a 6mt so I'm not sure how the auto tuning can or if it does affect the dme.

 

[martymil]

Still looks like its hpfp pressure related, when the pump starts to take a huge dive so does the timing trying to ease the dive, once it stabilises the timing and pressures start to rise.

 

[Silent11]

Still looks like its hpfp pressure related, when the pump starts to take a huge dive so does the timing trying to ease the dive, once it stabilises the timing and pressures start to rise.

in 4th it cut timing when the rail was 2200psi

 

[martymil]

They could be totally unrelated timing cuts, did you run with traction control fully off long press ?

Fourth gear is most likely related to lifting of the throttle.

 

[doublespaces]

I've switched this thread to question format and moved to Troubleshooting.

in 4th it cut timing when the rail was 2200psi

You also have to take into account that it is occurring at the same time your rail pressure 'maxes out' after coming from a figure way down low. Marty might have a point, you never know what kind of relationship that stuff has. Well, someone probably does but I don't. In these cases, it can be helpful to fix what you do know is wrong, like your rail pressure. That post shift rail pressure of like 700's is not healthy at all, get that fixed regardless of what this timing correction is caused by. Might even kill two birds with one stone.