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View Full Version : New n75 but still limp and more



BirdTurbo
06-05-2013, 01:17 PM
Well In my previous thread I had checked the boost leaks with diy contraption detector. Which I found air leaking under the intake manifold and also air leaking out of the dipstick and oil cap as I had added to much pressure. I had also disconnected the waste gate actuator hose and manged to get 10psi. Well my new n75 came in but here is the problem it is still limp (at one point it hit 7psi) it pulls a hell of a lot better than before. Could it be the new south boost gauge or is there some leak that I cannot find?[headbang][headbang][headbang][headbang][headbang]

redline380
06-05-2013, 01:23 PM
what codes do you currently have? if none, you may still need to reset the ecu by disconnecting the battery for a few minutes. but make sure you have your radio code handy if you attempt this

BirdTurbo
06-05-2013, 01:38 PM
Still no codes. well other than the test pipe and the evap canister disconnected which give a leak

BirdTurbo
06-05-2013, 04:24 PM
On my new south boost gauge it sits at below 17inhg without a/c and with a/c it fluctuates between 19,20,21,22 inhg. It still pulls hard though it mainly sits at 4psi now.

BirdTurbo
06-06-2013, 08:39 AM
BUMP

tHatOne guY
06-06-2013, 11:00 AM
On my new south boost gauge it sits at below 17inhg without a/c and with a/c it fluctuates between 19,20,21,22 inhg. It still pulls hard though it mainly sits at 4psi now.

Hmm. Usually see more vacuum with no A/C and loads, not the other way around.

10kredline
06-06-2013, 12:02 PM
I'm having the same problem, just installed a new N75 also. The codes I got was for the N75 and Primary o2 sensor. Vacuum is also below 20 inhg and still in limp mode. O2 sensors can cause a limp mode?

audi-medic
06-06-2013, 01:56 PM
I'm having the same problem, just installed a new N75 also. The codes I got was for the N75 and Primary o2 sensor. Vacuum is also below 20 inhg and still in limp mode. O2 sensors can cause a limp mode?

Check the tb

10kredline
06-06-2013, 04:45 PM
Check the tb

Yea, ill do that tomorrow and clean it. I already bought the o2 sensor since i got that code. Birdturbo, did you get it fixed yet?

audi-medic
06-06-2013, 07:04 PM
Yea, ill do that tomorrow and clean it. I already bought the o2 sensor since i got that code. Birdturbo, did you get it fixed yet?

More importantly align it after cleaning

BirdTurbo
06-06-2013, 07:28 PM
Hmm, so a remedy would be to clean the electrical connections and the throttle body plate with the crc throttle body cleaner? I will do it sometime tonight and of course then align it.

10kredline
06-06-2013, 08:48 PM
After cleaning the TB, the "chicken dance" to align the tb should work right? Vag com not required? because I don't have one.

BirdTurbo
06-07-2013, 09:29 AM
I'm absolutely sure it requires one.

audi-medic
06-07-2013, 09:43 AM
After cleaning the TB, the "chicken dance" to align the tb should work right? Vag com not required? because I don't have one.

1. Turn the key to the "ON" position, BUT DO NOT START THE CAR!
2. Leave the key in the "ON" position for 3 minutes WITHOUT TOUCHING ANYTHING.

3. After 3 minutes, turn key to the "OFF" position, then start the car as normal.

^^^ this is thought to be a myth by some and others have claimed it worked, i personally only use a vag so i wouldn't know, but you can try it and see if anything happens, never hurts to do the "chicken dance" :)

BirdTurbo
06-07-2013, 10:48 AM
Well since I cleaned it out again and did the adaptation. The throttle body after 30secs, went from 820 to 920 rpm. While on the boost gauge it still hovered at 17-18inhg. With a/c on it dropped to 720 and then hovered at 840 rpm. Also it hovered at 17-18 as well.


I have finally driven it and it still in limp mode it now hovers at 17-18inhg with a/c on and off.

BirdTurbo
06-08-2013, 09:50 AM
bump

audi-medic
06-08-2013, 07:25 PM
bump

Next step vacuum leak, take one step back and ask if the car ran properly before the gauge install, if so I would be checking the gauge/hoses, also I would be checking all vacuum anyways due to the slightly lower number that you have (I have around 22-24) for vacuum

10kredline
06-08-2013, 09:38 PM
Chicken dance didn't work, vag com need. Anyways, you should check for leaks, I think that's what I'm going to do also. So far I paid for a new N75, new front O2 sensor, used rear O2 sensor and clean TB, none helped...

audi-medic
06-08-2013, 09:45 PM
Chicken dance didn't work, vag com need. Anyways, you should check for leaks, I think that's what I'm going to do also. So far I paid for a new N75, new front O2 sensor, used rear O2 sensor and clean TB, none helped...

i think i would have bought a used vag for the same amount of money you just spent, much better investment, and makes it much easier to diagnose with, don't keep buying parts (guessing),

BirdTurbo
06-08-2013, 10:00 PM
I have one the vcheckers from esc tuning will that help? Also by vacuum lines, you mean the evap in the engine bay and not in the back of the car.

audi-medic
06-08-2013, 10:40 PM
Correct, if you haven't changed them since you bought the car or if they are still stock, change them ($5-10), also what do you have for a dv?

10kredline
06-08-2013, 10:55 PM
i think i would have bought a used vag for the same amount of money you just spent, much better investment, and makes it much easier to diagnose with, don't keep buying parts (guessing),

I wasn't guessing, I have a scanner that just reads codes but no vag com. It showed P0422 (Main Catalyst,Bank1 Below Threshold) and P1548 (Boost Pressure Contr.Valve Open). Still in limp mode..

10kredline
06-08-2013, 10:55 PM
I have one the vcheckers from esc tuning will that help? Also by vacuum lines, you mean the evap in the engine bay and not in the back of the car.

I'm thinkin about getting that scanner instead. Is yours the Pro version? How do you like it?

BirdTurbo
06-09-2013, 09:08 AM
Yeah I have the pro and it is pretty awesome. It can do many thing as it says on the website and it is damn good in pinch.

BirdTurbo
06-15-2013, 12:37 PM
I have been at it over an hour and still cannot for the life of me. Find that blasted leak? What else could it be, A faulty MAF or could it be the key that I'm using? (the only place it does leak is by the oil cap and dipstick and I have them off)

BirdTurbo
06-16-2013, 03:26 PM
bump

10kredline
06-16-2013, 04:30 PM
Try checking the inside of the cable/boot of the N75 cable. I finally fixed mine because the cable ripped inside, I had to re-clamp it. Spent all that money just to find that POS broken when everything else was OK.

kwnk
06-16-2013, 07:17 PM
did you check the two silcone hoses connected to the n75 for cracks?

Mad Cow
06-16-2013, 07:32 PM
I wasn't guessing, I have a scanner that just reads codes but no vag com. It showed P0422 (Main Catalyst,Bank1 Below Threshold) and P1548 (Boost Pressure Contr.Valve Open). Still in limp mode..

Take a step back and look at your codes, P1548 means N75 open circuit. Do you know what open circuit means? Why are you chasing boost leaks if the code says it's an electrical issue with the N75 circuit? Check your harness instead before throwing parts at the problem.

BirdTurbo
06-17-2013, 12:44 PM
The hose that lead to their respective nipples are okay but the cable that leads to n75 is a good idea. When I get time I will check it out!!1

10kredline
06-17-2013, 12:57 PM
Take a step back and look at your codes, P1548 means N75 open circuit. Do you know what open circuit means? Why are you chasing boost leaks if the code says it's an electrical issue with the N75 circuit? Check your harness instead before throwing parts at the problem.

...uhh....in the code description, just says whatever I posted...didn't say "open circuit", until one of you guys told me, then I checked it. If the I saw the key word..."circuit", then I would of checked it in the first place. Seriously, why is everyone being a smartass all of a sudden. This B5 section has changed a lot....[confused]

Edit: There's a first time for everyone, not everybody is mechanically inclined, that's why I'm here to ask questions and learn...not expected to know everything all of a sudden...

walky_talky20
06-17-2013, 01:12 PM
For the open circuit code, I would proceed like such as:

- unplug N75 and put a test light across the 2 harness terminals
- Use VCDS Output Test Mode (or equivalent on your scan-y thingy) to cycle N75 repeatedly
- Watch for flashy light
- Flashy light = harness is very likely just fine.
- Check resistance of N75 with ohm meter.
- If resistance is good, then problem is "intermittent" (ie: circuit breaks with vibration or something, could be the valve or the harness). Requires more diagnostics.

BirdTurbo
06-17-2013, 01:29 PM
That is good to know whenever I check the harness

BirdTurbo
07-02-2013, 09:08 AM
Well I finally installed the new MAF and removed the redneck airbox mod. Still to no avail I'm in limp mode and my idle is uncomfortable rough even though everything is sealed. So That crosses out that and now onto the wiring harness. Also finally managed to get a code for limp mode so I must be making progress eh?



For the rough idle what could it be if it isn't the new MAF? Could it be the throttle body?

BirdTurbo
07-04-2013, 11:02 AM
bump

10kredline
07-04-2013, 02:56 PM
Try cleaning out the throttle body, it'll make a world difference.

kwnk
07-04-2013, 04:27 PM
hey did you ever figure out the issue? or check those two n75 hoses for cracks?

I had the same issue where id hit limp mode after boosting over 4psi. I replaced the n75, MAF, etc. I had normal vacuum but it was only while in boost that it would cut.

It turned out that those two hoses connected to the n75 were cracked at the bends (i had no idea they were cracked until further inspection)

I replaced them with these (which are not bent to begin with -- the old hoses had 90degree bends) http://www.ecstuning.com/Search/SiteSearch/N75_Hose/ES277693/

its been boosting well since

hope you figure it out man..

War Machine
07-04-2013, 04:47 PM
Its very easy to pressure test a system, I made a tester for $10 at home depot.

https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-frc1/310028_546997611990818_644557807_n.jpg

Clamp that into your TIP, and slowly pump air into the system with the car off. Listen for leaks, cheap, easy, and very effective.

Also, are you sure the N75 is installed correctly? As well as check the wires directly at the connector, they fray and tear easy with age.

And this is a very dumb question, but easily overlooked. you have CLEARED the codes, and the come back right? When I replaced my N75, I was in limp mode until I cleared the code via vagcom.

BirdTurbo
07-04-2013, 07:17 PM
Well my throttle body is sparkly clean. The pressure tester I made 4 years ago did not pick up anything unless I'm supposed to remove the dipstick as well with the oil cap which I didn't hawhaw. When I pressure tested it for 6th time I had my dad look with me (sprayed with soap and we could not find anything. Although I should of course check again when I do the voltage test on the connector.




It still doesn't account for the rough idle as the throttle body is relatively new and a new maf as well?
Also does someone have a link for a new harness for the n75?
thanks for the help

BirdTurbo
07-07-2013, 03:54 PM
BUMPOPOOO

BirdTurbo
07-11-2013, 09:36 AM
P17544*P1136 Bank Mixture adaptation (system to lean).
From v checker pro they code pops up now due to the new MAF and now I have to evap codes instead of one now which are P1475 EVAP control leak detection pump and P0441 Evaporative emission incorrect purge flow.|





BUMP