2G Fouling plugs

[MarcVIII]

Its a 97 Tsi AWD. I just put a new 3" turbo back exhaust w/ hi-flow cat. I cleaned out the EGR valve under the throttle body (valve moved when I used an air hose, so seemed it seemed to work to me.) I cleaned the throttle body. The car fouls plugs VERY fast (~less than 5 miles drive, new plugs). They are black w/ carbon build-up. I need this thing to pass e-check and run properly. I've modded the BCS valve and the dump tube, 1g Bov on UICP- nothing that would hinder air flow, so I don't know why this is happening or what to do. Stock boost setting BTW. The wires are magnecore w/ ~10-13k miles i believe. Just trying to tell everything I can to get this righted. The car will run with clean plugs for a while, blew black smoke with partial accel. Stopped doing that, so I assumed it was remnants of the carb / TB cleaner. Any ideas as to what this could be? No CEL, no codes. Car has plenty of power and starts with no trouble with the new plugs. Autoparts store was thinking Fuel Pressure Regulator.

 

[szewczyd]

You must be running super pig rich? Black clouds behinde you? Get a logger or some type of monitoring system on it.

 

[ddavisaf]

First thing I would run is a boost leak test. Your FPR doesn't need to be hooked up, so if you're concerned about that disconnect the vaccum lines and plug everything off. You'll know it's bad when it clicks constantly.

 

[MarcVIII]

Talking to autoparts store people, service shops ALL DAY when I wasn't testing and cleaing emissions parts- they think its the EGR or IAC. The EGR opens with 20 psi vaccuum (used a hand vac tester). It was horribly full of carbon though after cleaning it w/ carb cleaner. Also the entire intake is blackened by carbon. Sprayed a lot of cleaner in there too. Cleaned all the holes in the TB as well. What should the stock FPR function at? I'm guessing 20-25 psi. I was thinking maybe getting an ebay adjustable FPR. I think the IAC is fine cause I don't have Idle surge issues. But when its cold it idles low (200-300 rpm) until it warns where it reaches normal (700-800 rpm), not surging but constant at the low until the motor is warm. Might be the screw not adjusted properly? Its an auto trans w/ shift kit.

Still I have NO CELs (OBDII test at autozone came up with no codes.) That guy said it could be something a sensor wouldn't see. He suggested the FPR might be open and dumping excess fuel. Also ran a compression test and got 160s. Put a friction modifier in the oil to thicken adhereance, hoping to aide in compression a few points (Valvoline Maxlife oil addiitive), didn't have time to recheck. Running stock gap spark plugs and tried dual tip NGK-R plugs too, still fouled both. Plug blasted them with a spark plug sandblaster (GREAT INVENTION BTW) to determine that it takes 15 minute to have complete surface carbon build-up, sooty black. Doesn't smell like fuel or have soaked plugs like before though.

 

[MarcVIII]

No leaks in boost. Cleaned the EGR again, cleaned the intake more. What's stock FPR maximum psi output?

 

[MarcVIII]

Turns out my EGR valve was "crushed" a little and seemed more resistant to opening than a new one. I also put on a new PCV valve seeing as it was only $4 and an intake breather. I put a bolt in the stock intake snorkel to prevent, uncounted and unclean air in. Car seems much better. Also my "fails" were because E-check messed up and ran me on an High Idle test (check emissions at 2500 rpm, right where boost is kicking in). So 2Gers make sure you refuse any other test besides an OBD-II or they'll give you a ton of run around (Ohio EPA).

But it was cold today (snow) and I noticed that the car will run fine, but when I hit boost it bogs for a moment then catches itself. I'm not sure if its backfiring or just sputtering but there is a jerky hesitation. Seems to be at 3800-4200 rpms where it sputters, while boost is coming in. It seems to dissappear almost once the car warms up, where it becomes a very sporadic hiccup. I'm reasonably sure that I don't have a boost leak as the aftermarket gauge holds steady as a rock. I could check timing I suppose, but doubt that its off since it seems to run "right" most of the time and everything else seems fine except for this spot where it goes from no boost to boost. I was considering that maybe I still have old carbon in the engine and its gumming something up? Or maybe the bolt in the intake snorkel loosened or fell allowing in additional, "uncounted" air? Might the fuel pressure regulator be acting up as previously suggested?

The plugs were the proper brown color and the electrode was also nicely colored, but away from the tip and electrode there was still carbon build-up on the plug. They did not smell like fuel like they did before, but rather properly combusted scent.

I want to get this resolved now and toss on a 1g TB as well as my turbonetics MBC.

 

[Blakedwight4]

Turns out my EGR valve was "crushed" a little and seemed more resistant to opening than a new one. I also put on a new PCV valve seeing as it was only $4 and an intake breather. I put a bolt in the stock intake snorkel to prevent, uncounted and unclean air in. Car seems much better. Also my "fails" were because E-check messed up and ran me on an High Idle test (check emissions at 2500 rpm, right where boost is kicking in). So 2Gers make sure you refuse any other test besides an OBD-II or they'll give you a ton of run around (Ohio EPA).

But it was cold today (snow) and I noticed that the car will run fine, but when I hit boost it bogs for a moment then catches itself. I'm not sure if its backfiring or just sputtering but there is a jerky hesitation. Seems to be at 3800-4200 rpms where it sputters, while boost is coming in. It seems to dissappear almost once the car warms up, where it becomes a very sporadic hiccup. I'm reasonably sure that I don't have a boost leak as the aftermarket gauge holds steady as a rock. I could check timing I suppose, but doubt that its off since it seems to run "right" most of the time and everything else seems fine except for this spot where it goes from no boost to boost. I was considering that maybe I still have old carbon in the engine and its gumming something up? Or maybe the bolt in the intake snorkel loosened or fell allowing in additional, "uncounted" air? Might the fuel pressure regulator be acting up as previously suggested?

The plugs were the proper brown color and the electrode was also nicely colored, but away from the tip and electrode there was still carbon build-up on the plug. They did not smell like fuel like they did before, but rather properly combusted scent.

I want to get this resolved now and toss on a 1g TB as well as my turbonetics MBC.

Did u ever figure this out

 

[pauleyman]

Did u ever figure this out

You can check the stats on the OP. He hasn't been seen in almost a decade and this thread is 18 years old. You won't find your answer from this thread. I suggest starting your own post

 

[curt-s]

Some say his plugs are still fouled to this day...