Surge, not the refreshing drink.

[skyshadow07]

I have noticed a problem now that speed season has opened back up. My car has a surge or skipping slipping feeling when WOT at high rpm, right before shifts. I tested today and found the effect is not present when the trans is only 100ish degree. But I begin to feel it more as the trans warms up. When the trans is 135ish deg, I feel it hard between 2nd and 3rd. I also found a wet spot on the top of my trans. When I do a pull, I can lightly smell burning oil or maybe trans fluid, my sniffer sucks. Any ideas? I know surging can be everything from a lean condition to a torque converter to a sensor to possible condensation in my WAY over sized intercooler.. it could be a million things, which sucks. I added a video to help you understand where the wet area is on the trans.

https://photos.app.goo.gl/89HwubomkLHdx1N66

 

[FiveLeeter918]

Any torque source codes when it happens?

 

[skyshadow07]

codes? like check engine codes? None of those if that's what you mean.
Torrie looked at some logs and said my fuel pressure was all over the place. My concern is this is a tune that's over a year old. Why is the fuel pressure just now becoming wonky? You think maybe the low pressure fuel pump is not pushing the proper amount of volume?

 

[FiveLeeter918]

codes? like check engine codes? None of those if that's what you mean.
Torrie looked at some logs and said my fuel pressure was all over the place. My concern is this is a tune that's over a year old. Why is the fuel pressure just now becoming wonky? You think maybe the low pressure fuel pump is not pushing the proper amount of volume?

not CEL, you can log a PID called "Torque Source" that will note the reasons why throttle closes under load. Is throttle fluttering on the log at all?

 

[skyshadow07]

I can email you logs if you want. Even though I am an engineer, you guys are the real wizards with this stuff. I am not sure I am even logging the proper parameters.

 

[stripSHO]

I can email you logs if you want. Even though I am an engineer, you guys are the real wizards with this stuff. I am not sure I am even logging the proper parameters.

You could just attach them as a .zip to this thread too. I’d be willing to take a looky

 

[skyshadow07]

Any specific parameters I should be logging?

 

[stripSHO]

Are you using HPTuners or SCT? Just toss up what you got and go from there. Or pm me for email if you’d prefer that way

 

[skyshadow07]

Here are three logs, the surging came on harder with each log, 01 being the least, 03 being the most.

 

[skyshadow07]

here are two more logs from after he reduced the boost to account for fuel pressure. The second log is on meth (20m/80w blend).

 

[stripSHO]

So your boost pressure seems really jittery across all these logs IMO, but in log 3 it comes completely off the rails. You can see the throttle opening/closing to try and maintain load as boost is swinging 2-3 psi. I can't see your trans causing this but I'm no expert. Seems to really struggle through 2nd gear where you are targeting far less boost but smooths out as soon as you get into 3rd and start loading up. Looks to me like a problem with the wastegate controls.

If it were my car, I'd be checking all wiring and tubing relating to the wastegate controls for cracks or leaks. Check out linkages, rumor has it they're prone to coming loose! Then I'd probably use a hand air pump to manually stroke the wastegate actuators, making sure they move freely & smoothly, and that the each respond equally to a given pressure input. Beyond that, ya got me.

I'm guessing that these logs came from an ngauge. I read those apparently have a 23 PID limit which is tough; I typically log 60 or so. But of the ones that are available, these are probably the most helpful to log for your current situation. In normal circumstances I would probably drop the bottom four and put back in the stft and ltft for each bank.

boost
rpm
ect
iat2
oar
commanded equivalence ratio
spark total
torque source
knock
lambda 1
lambda 2
load
etc actual
etc desired
hpfp duty cycle
fuel rail pressure
TIP
TIP desired
wgdc
speed ratio across tc
trans slip ratio
trans fluid temp
trans pressure

 

[skyshadow07]

Good info. I have a massive (24x12x4) FMIC. You think that could be causing the pressure problem? I'll check the wastegates and do I leak test.

 

[stripSHO]

Good info. I have a massive (24x12x4) FMIC. You think that could be causing the pressure problem? I'll check the wastegates and do I leak test.

I dunno. Maybe if it's got a gallon of water sitting in it?

 

[skyshadow07]

Riddle me this Batman. So I recently got a P0627 code as my car died three times in a row. That code is for "Fuel pump "A" Control Circuit Open". I narrowed it down to the fuel pump drive module, also called the fuel pump power module being the most likely culprit. I bought the Dorman reman for the module and installed it. Code is gone, car is back up and running AND now the surge is gone. Only thing I can think is the surge was the HPFP pulling fuel while the module was failing to switch from 80% to 100%.
Ideas? Opinions?

 

[stripSHO]

Riddle me this Batman. So I recently got a P0627 code as my car died three times in a row. That code is for "Fuel pump "A" Control Circuit Open". I narrowed it down to the fuel pump drive module, also called the fuel pump power module being the most likely culprit. I bought the Dorman reman for the module and installed it. Code is gone, car is back up and running AND now the surge is gone. Only thing I can think is the surge was the HPFP pulling fuel while the module was failing to switch from 80% to 100%.
Ideas? Opinions?

Hmmm... the ECU does have the ability to close the throttle if it calculates that you're running out of fuel based on injector duty cycle. But, there's nothing in your logs to suggest that you were remotely close to such conditions. Plus I've hit that threshold many times and it is a fairly smooth throttle modulation, not something you can easily feel. Dunno man, but glad you're fixed

 

[skyshadow07]

LPFP took a **** on me so I replaced it. I'm having the turbos replaced next month so I'll have the wastegates checked or replaced. Would you do stock or the turbosmart?