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View Full Version : C7 A6 Idle Issues after more Mods



krwalkman
09-10-2020, 08:00 AM
Hello AZ brain trust.

I have recently installed a short list of additional mods and done some recent maintenance, See these below:

MODS

196.5mm Crank Pulley
Autotech HPFP Mod
CWA100 Aux Water Pump
Ported Blower
Replaced 74.5mm Iabed Throttle body that started whistling after porting (just bought same throttle body from Bosch)

Maintenance Items

Valve Carbon Cleaning
PCV Replaced
Fluid Changes


After doing all this at once my car is having some trouble idling. I am getting some codes, but the Carista I have is giving me codes but nothing comes up after searching for them on Google, thinking Carista sucks. Check engine light is on:
Immediately after startup the car revs way higher than usual. It revs up to about 1850 RPMs and then drops down to 400 RPMs and stutters then revs back up to about 1850 again. This process repeats itself for a while and then it will eventually settle down to revving between 1600 and 1800 bouncing between the two at about 2 second intervals.

My immediate thoughts are that it isn't ready for a new throttle body, maybe it needs to be adapted via VCDS, this is in the works for someone to come up and help with that this weekend. My other thoughts is, maybe APR Stage 2 isn't ready for all this and doesn't know what to do with the extra airflow through the blower. I have been stage 2 for a year or so, and have had the bigger throttle body on with no problems, didn't need to adapt to anything that time. So Could the larger pulley ratio and Ported blower or even the fuel pump be throwing off the tune and it is just trying to balance itself using larger amounts of air or fuel?

I know without the codes it's sort of difficult to diagnose, but if someone has run into this, I could use the experience. I have not driven it in it's current state, so I couldn't tell you how it performs on the road.

As a side note, we just upgraded the SQ5 to IE Stage 2 Dual Pulley and I can tell you, stage 2 DP from IE feels way faster than APR 2 DP. That thing rips. Now that we have the cable already I am contemplating switching to IE and getting a tune that is set up for all the mods. I think I have everything listed in my signature if you want to look, but the gist of it is in this post.

Thanks for reading,
Kyle

daytona rs7
09-10-2020, 08:12 AM
did you do throttle body adaptation after replacement?

gk1
09-10-2020, 08:45 AM
Hey man,
Wow, long list of work there. My first though goes to some type of air or vacuum leak. Any of those small hoses could be loose or could have broken with that much work. Any strange noises like you'd suspect with a vacuum leak?

Did you try this: (I never got it to work this way, but can't hurt to try.)
Manual throttle body adaptation:
-Put car in accessory mode (engine off).
-Press the gas pedal to the floor.
-Hold the pedal to the floor for five seconds, then press button to switch it off, then release the gas pedal.
-Wait 2 mins. for a full alignment. During this time you may hear very faint noises and clicks.
-Drive the car as normal.

Also what happened to the ported Iabed that made it whistle? Was it over-zealously ported? any chance that happened to the blower too? Doe the car idle properly with the old TB just whistles?

I'm sure I'm wrong, but I thought the larger throttle body needed the APR Stage II+ Ultra software? I don't know if that would cause an idle issue like you are seeing since you said you were already running a larger throttle body before, but I thought I read a thread stating the larger throttle needed the different software. Like I said... I could be totally wrong.

What codes did Carista give anyway?

Let me know... I can always lend a hand.

krwalkman
09-10-2020, 12:01 PM
did you do throttle body adaptation after replacement?


Hey man,
Wow, long list of work there. My first though goes to some type of air or vacuum leak. Any of those small hoses could be loose or could have broken with that much work. Any strange noises like you'd suspect with a vacuum leak?

Did you try this: (I never got it to work this way, but can't hurt to try.)
Manual throttle body adaptation:
-Put car in accessory mode (engine off).
-Press the gas pedal to the floor.
-Hold the pedal to the floor for five seconds, then press button to switch it off, then release the gas pedal.
-Wait 2 mins. for a full alignment. During this time you may hear very faint noises and clicks.
-Drive the car as normal.

Also what happened to the ported Iabed that made it whistle? Was it over-zealously ported? any chance that happened to the blower too? Doe the car idle properly with the old TB just whistles?

I'm sure I'm wrong, but I thought the larger throttle body needed the APR Stage II+ Ultra software? I don't know if that would cause an idle issue like you are seeing since you said you were already running a larger throttle body before, but I thought I read a thread stating the larger throttle needed the different software. Like I said... I could be totally wrong.

What codes did Carista give anyway?

Let me know... I can always lend a hand.

No I didn't do that, I honestly had no idea that you could do it in a manual fashion so I am going to try what GK1 said with my fingers crossed.

There aren't any discernible noises at this point that would make me think vacuum leak, but I'll report back after having a go at that adaptation.

For the ported iABED it was just a little overzealous indeed. Seems like we clipped the plate a little with the die grinder so I assume that's where the whistle came from. It ran with the ported TB on it, it was just a bit annoying so I bought that replacement. When I changed to the new throttle body that's when it started the newer idle thing, but I also changed the SC at that point as well. The blower was tested by the guy who ported it and I'm pretty confident it doesn't stem there, unless maybe I hooked a hose up to the wrong place when reinstalling, but it seems pretty straight forward.

So APR has their ultracharger tune, but it is only available if you buy their ultra charger which is way over priced. I ran the Iabed throttle body for about 4 months and had no issues with the tune. I just put it in and drove.

I'll pull some codes with my MPVI2 and see what happens. Will report back.

f4m0u5
09-10-2020, 12:23 PM
No I didn't do that, I honestly had no idea that you could do it in a manual fashion so I am going to try what GK1 said with my fingers crossed.

There aren't any discernible noises at this point that would make me think vacuum leak, but I'll report back after having a go at that adaptation.

For the ported iABED it was just a little overzealous indeed. Seems like we clipped the plate a little with the die grinder so I assume that's where the whistle came from. It ran with the ported TB on it, it was just a bit annoying so I bought that replacement. When I changed to the new throttle body that's when it started the newer idle thing, but I also changed the SC at that point as well. The blower was tested by the guy who ported it and I'm pretty confident it doesn't stem there, unless maybe I hooked a hose up to the wrong place when reinstalling, but it seems pretty straight forward.

So APR has their ultracharger tune, but it is only available if you buy their ultra charger which is way over priced. I ran the Iabed throttle body for about 4 months and had no issues with the tune. I just put it in and drove.

I'll pull some codes with my MPVI2 and see what happens. Will report back.



do you still have old throttle body that whistled? i would try reinstalling that and see if idle settles. if not id think something with supercharger or install since then that would-be the only change

krwalkman
09-10-2020, 01:16 PM
I couldn't tell you why I have not tried that. I certainly have it.

krwalkman
09-10-2020, 01:27 PM
Here are the codes I get:
0x7E8: P0068 - MAP / MAF - Throttle Position Correlation (Pending, Permanent)
0x7E8: P0507 - Idle Air Control System RPM Higher Than Expected (Current, Permanent)

I did the Manual Throttle body adaptation and it seemed to help the idle a bit, still pretty unsteady though. Must be a leak somewhere.

I'll try the old Throttle body and check.

Dutch_A6
09-10-2020, 01:46 PM
Might also be a harness issue with the TB, I've seen that be the cause of that MAF error before.

Sent from my Pixel XL using Tapatalk

gk1
09-10-2020, 02:32 PM
Here are the codes I get:
0x7E8: P0068 - MAP / MAF - Throttle Position Correlation (Pending, Permanent)
0x7E8: P0507 - Idle Air Control System RPM Higher Than Expected (Current, Permanent)

I did the Manual Throttle body adaptation and it seemed to help the idle a bit, still pretty unsteady though. Must be a leak somewhere.

I'll try the old Throttle body and check.

Yeah manual doesn't give much details on those codes....except to say they are TB related, so either trying the old one back in there or redoing everything on the new one including a proper VCDS throttle alignment might help.

P0507 - Idle Air Control System RPM Higher Than Expected - Idle Controller out of range high
Check the Throttle Valve Control Module - J338- which is in the TB.
• CONNECT: Scan Tool.
• IGNITION: ON
• CHECK: throttle valve position closed:
• SPECIFIED VALUE: 3 – 25%
• DEPRESS: Accelerator pedal slowly to WOT while observing the percentage display. The percentage display must increase uniformly
• CHECK: throttle valve position at WOT:
• SPECIFIED VALUE: 84 – 97%
• IGNITION: OFF
If that checks out, then it just says it may be intermittent and to check wiring.
otherwise...
REMOVE: Throttle Valve Control Module -J338 - far enough so that the connector terminals are accessible.
• DISCONNECT: Throttle Valve Control Module - J338 - connector.
• IGNITION: ON
• CHECK: Throttle Valve Control Module - J338 - connector terminals 2 to 6 for voltage
• SPECIFIED VALUE: About 5.0 V
• IGNITION: OFF
If ok then check wiring again...lol
otherwise there are checks to test connections between the TB and ECM, but hopefully that is not your issue.