Start Up Issues

mr.zeros said:

bump. So I've got a theory. This might be the N80 valve. Yesterday, I went to the gym. Parked the car for an hour and then restarted it to drive home. The temperature needle was in the righ spot, about 10 o'clock. I opened the hood and unplugged the electrical connector to the N80 valve. No rough start/stall! Plugged the N80 valve back in right after starting, nothing weird, the engine continued running fine.

Another thing. Apparently this part was redesigned sometime between 2011 and 2014, because Europa Parts shows this (also says it is VIN specific):
http://www.europaparts.com/purge-valve-037906283c.html

but clearly on this thread: http://www.golfmk6.com/forums/attachment.php?attachmentid=26372&d=1352864528
You can see the N80 valve style that I have.
Looks like this one (and it's a lot cheaper!):
http://www.europaparts.com/purge-va...gle_shopping&gclid=CPn0o4KzgcACFSbl7AodeXEAOw

So, I'm not sure if the problem is a bad N80 valve, or bad wiring/grounding, or bad control from the ECU, but this is definitely something.

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I agree. You and I have talked about this issue quite a bit in the past. I definitely think its ECU related, meaning stock software. You may also be on to something with the N80 valve.

The whole engine temp thing is just really weird. Its like it throws things off because its not a hot or cold start so certain conditions are not set and the car just clunks and doesn't turn over. I find that if I just turn the key quicker instead of turning it to on, it happens less. Who knows.

Just to note. This has happened to me with apr stage 2, apr k04 and unitronic k04 software. I've replaced the fuel filter twice and plugs and coils plenty of times. Car runs great and always has.

Even though the ECU is flashed there are still stock manufacturer parameters on the ECU that are untouched and still have an effect and this is where I think the problem is because too many are having this problem under the same condition:

Motor just ran for a short time, coolant temp gauge at 9 to 10 oclock.

I just tried again unplugging what I think is the N80 (on the chart, it is #17). This is not the N80 according to the Europa Parts or ECS Tuning catalog, but it is the N80 according to Deutsche Parts (see here: http://www.deutscheautoparts.com/Vi...uum/06J-133-781-CE/06J-133-781-CA/1831/140673)

ANyway, I unplugged the electrical connector and same thing. Rough idle at first. I also tried disconnecting the hose that runs to the charcoal canister and capping it off, with and without plugged in. Same thing, no improvement.

Referring to this thread:
http://www.golfmk6.com/forums/showthread.php?t=74266

I measured the resistance of the N80, it was 36 ohms. I measured the voltage at the connector and got about 8.3 volts. The way this sensor is controlled, according to the wiring diagram, is the positive voltage is connected to the battery (through fuse 24 and a relay). The solenoid is pulled high or low by the ECU directly. This almost sounds like a bad grounding problem or something.

I might try measuring the resistance from the ECU chassis to the engine and see if there is a bad ground. **edit: measured it. Resistance from the alternator body to the ECU chassis is like 0.2 ohms, which is swell. No idea.

mr.zeros said:

I just tried again unplugging what I think is the N80 (on the chart, it is #17). This is not the N80 according to the Europa Parts or ECS Tuning catalog, but it is the N80 according to Deutsche Parts (see here: http://www.deutscheautoparts.com/Vi...uum/06J-133-781-CE/06J-133-781-CA/1831/140673)

ANyway, I unplugged the electrical connector and same thing. Rough idle at first. I also tried disconnecting the hose that runs to the charcoal canister and capping it off, with and without plugged in. Same thing, no improvement.

Referring to this thread:
http://www.golfmk6.com/forums/showthread.php?t=74266

I measured the resistance of the N80, it was 36 ohms. I measured the voltage at the connector and got about 8.3 volts. The way this sensor is controlled, according to the wiring diagram, is the positive voltage is connected to the battery (through fuse 24 and a relay). The solenoid is pulled high or low by the ECU directly. This almost sounds like a bad grounding problem or something.

I might try measuring the resistance from the ECU chassis to the engine and see if there is a bad ground. **edit: measured it. Resistance from the alternator body to the ECU chassis is like 0.2 ohms, which is swell. No idea.

Click to expand...

So at this point and time, you no longer suspect the N80 valve?

FocalPoint said:

So at this point and time, you no longer suspect the N80 valve?

Click to expand...

I'm out of ideas at this point. Maybe it's the ECU? I doubt it's the N80, but I only blocked off one line. There are several other vacuum lines involved, maybe I should try clamping those off.

Okay let me add some backstory. I took my car to the local VW dealer. The tech said the in-tank fuel pump had low pressure (3-3.5 bar, spec 4-8). His diagnosis was to replace the fuel pump and perform carbon cleaning to the tune of $1700. I said no. Called VWOA and went through the case process. I explained to them that this has been an ongoing issue for me with 3 documented repair visits and case. They agreed to pay for 50% of the repair cost to do the carbon cleaning and fuel pump, which would then put my out of pocket cost at almost $700. I am out of warranty (43k miles), but took the car in for this issue at 17xxx, 18xxx,22xxx,22xxx,22xxx.
Can't lemon law because I am not the original owner. I might as well be persona non grata.

Given the nature of this problem, the fact that I can shut of the engine and immediately restart it with a rough idle/sputtering/stalling, rev the engine and all is well. Given that, I highly doubt the LPFP or carbon is to blame. And I'm not about to throw away $700.

I'm at 36k and the new APR K04 file caused this problem for me. Proper plugs properly gapped did the trick for me.

motodude310 said:

I'm at 36k and the new APR K04 file caused this problem for me. Proper plugs properly gapped did the trick for me.

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That's interesting. I had this issue on stock plugs. Did you have it on the factory plugs?
I have since swapped to the NGK BKR7EIX but I am using the factory gap which is 0.032" I think. I've heard the factory gap is 0.028". Could that be the problem?

That might be it, but I kind of doubt it. The tune must be REALLY sensitive to temperature if that is going to make a difference. The car starts up fine hot and cold. It's only the in-between part where it takes two tries to start up smoothly.

Regaled to .028ish. Between 0.7 and 0.75 mm using my metric feelers. Will report back.

I was running pregapped to 0.032" NGk iridium plugs, which looked fine with a clean electrode btw. So maybe this will help the startup.

mr.zeros said:

Regaled to .028ish. Between 0.7 and 0.75 mm using my metric feelers. Will report back.

I was running pregapped to 0.032" NGk iridium plugs, which looked fine with a clean electrode btw. So maybe this will help the startup.

Click to expand...

No luck. Regapping to 0.028" did not correct the sputtering startup issue for me. Bummer.

Check this out. Tiguan recalled for a fueling issue resulting in a stall after restart. Brilliant. Now when does the GTI get the recall?

The recall affects approximately 151,389 model year 2009-2014 Volkswagen Tiguan vehicles. In isolated cases, it is possible that gas bubbles may form in the fuel system when winterized fuel with high vapor pressures is used in warmer areas or during months with higher ambient temperatures or during engine hot soak. The condition occurs when the engine is restarted within a short period of time, before the engine has fully cooled down. When the vehicles affected by this recall have been operated under low load for an extended period of time, deposits may collect and degrade the electrical current flow inside the in-tank fuel pump, thus leading to reduced fuel pump performance and pressure. If these conditions occur in combination, the fuel pump may not be able to overcome the vapor pressure under low loads and can potentially result in a vehicle stall directly after engine start. Potentially, this could lead to a crash.

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http://www.autoblog.com/2014/08/11/volkswagen-recalls-150k-tiguan-fuel-bubbles/

Let's get vwoa on the phone