Limp Mode Charge Pressure Exceeded with Logs

[DannyC87]

Is this possible? I have a 2 port MBC in parallel with my N75 to stop boost spikes. Occasionally my boost is limiting to 6psi; but after a good stint of full throttle will shoot back up to normal levels ~24psi peak. I am thinking either my MBC is sticking keeping the wastegate open; or i'm going into limp mode. Just need to know if limp mode can occur without warning lights?

Thanks

Dan

 

[Jimski]

Yes dude, limp mode will occur without any indication, your best bet is to get VAGCOM out when you notice the 6psi kick in!


Jimski

 

[DannyC87]

Yes dude, limp mode will occur without any indication, your best bet is to get VAGCOM out when you notice the 6psi kick in!


Jimski

thought you might say that.. will have to keep vagcom with me at all times then..bugga!
cheers

 

[DannyC87]

Right; I got vagcom on the car today when the boost limit occurred; fault code: 17963 P1555 Charge Pressure Upper Limit exceeded.

I reset the code and did a quick log of actual vs. requested boost; and achieved this in third gear:

I am going to do a 4th gear log tonight to see how that looks. Any thoughts on the correct graph?

 

[DannyC87]

for a 4th gear run, what rpm should I try to start and finish at? What blocks should I log other than 002 & 115?

 

[DaNnY_LaD]

What turbo is this?

As my Gt2x was set too high for the map...24psi turned it down to 22psi peak and it held it to the redline...

 

[DannyC87]

K04 standard lcr turbo, stage 1 map

 

[DannyC87]

4th gear logs:

 

[wild willy]

turn the mbc down a little.

 

[DannyC87]

what should I be peaking at? around 22psi?

 

[wild willy]

What map you running mate, a stage one remap shouldn't be giving you these issues. Have you replaced or adjusted your actuator.

 

[wild willy]

what should I be peaking at? around 22psi?

Yes, dropping to about 15-16 at red line.

 

[DannyC87]

not touched the actuator after reading about it voiding my turbo warranty.. its a p-torque stage 1 map. so far tried new n75; still peaked to 28psi = occasional limp mode; now using mbc (2 port type, not bleed type) in parallel with n75 and getting limp mode; but much less often - maybe just dial spike down a tad more with mbc?

 

[DannyC87]

Yes, dropping to about 15-16 at red line.

after the initial spike, the boost does as it should, and falls to 16ish at the redline; limp mode only happens right after the initial spike; and this is only when pulling a high gear a relatively low revs.

 

[wild willy]

after the initial spike, the boost does as it should, and falls to 16ish at the redline; limp mode only happens right after the initial spike; and this is only when pulling a high gear a relatively low revs.

Give Will a ring @ Ptorque or link him too this thread, he'll sort you out no problem.

 

[DannyC87]

I'm trying to avoid another trip over to Wolverhampton I'll turn the MBC down a bit and see how she runs at the weekend; got a couple of long trips so i'll take vagcom with me so i can check any error codes etc en route.

 

[P-torque.co.uk]

Hi Guys

The Leon Cupra R only has 1 software version, and theres 14 other members on the forum alone running the software, its certainly not requesting 28psi

Strange boost pattern you seem to be getting...

If you have changed the N75 already, then the wastegate may be sticking..

Also, check the hose leading from the N75 to the turbo

 

[DannyC87]

Hi Guys

The Leon Cupra R only has 1 software version, and theres 14 other members on the forum alone running the software, its certainly not requesting 28psi

Strange boost pattern you seem to be getting...

If you have changed the N75 already, then the wastegate may be sticking..

Also, check the hose leading from the N75 to the turbo

Does the 4th gear requested vs. actual log look ok? Actual only briefly goes above requested, and that is only around 23-24psi when converted assuming mbar at atmosphere is 990 ish.

 

[DannyC87]

Also, what blocks should I log to check the N75 duty cycle? and how are the results interpreted? cheers

 

[P-torque.co.uk]

Hi

1.5 bar is normal (23psi)