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Low BoOst - Black Smoke under full throttle

Posted: Jun Tue 16, 2009 1:57 pm
by Dubber
Alright - Lots of fun, but I think I am getting closer on the boost problem I am having, mainly because we have a new symptom.

The car will only boost at 15 pounds now, no matter what gear. first does about 8, which is what stock is, and in all subsequent gears it spikes at 15 and holds at ten. Much lower boost than originally.

After the car is hot, and has been driven hard through a couple of gears, the car feels like its .. choking or stumbling a bit and starts to spew black smoke in the top of the gear.

I looked at Vag com - it tells me my cat is fine, my 02 sensors are fine
but it does have on measuring block 032 the running adjustments from the 02 sensor are at -18.4 which there is a value limit between -10 and 10
after some research it still looks like i have a boost leak somewhere. have not found it..
I do have a couple of codes now.
all intermittent and none of them came back right away after clearing it.

16712 Knock sensor 1 (g61) Signal too high
p0328 35-10 intermittent


and

16490 - manifold/barometric pressure sensor (g71) f96 implausible signal
p0106 - 35 -10 intermittent



anyone have any ideas as to what is going on??
I have heard maybe turbo??
I checked the vag com measuring block for my mass air flow sensor, they look good.
confused..
any ideas are appreciated

Re: Low BoOst - Black Smoke under full throttle

Posted: Jun Tue 16, 2009 2:08 pm
by Roadhog
black smoke is from running too rich. Is your knock sensor bad?

Re: Low BoOst - Black Smoke under full throttle

Posted: Jun Tue 16, 2009 3:16 pm
by Mikewire
You know my laptop you have right now has a factory MKIV repair manual on it? You could look those codes up and see what to check. There's a link on the desktop called Ebahn Reader.

I would look it up for you but.................................................... :laughing:

EDIT: And I'm throwing this out there: How long have you had that CAI installed? Was it giving you these symptoms before you installed it or after?

You get a good look at your wastegate and rod/actuator? It could be not opening all the way or stuck. You could put artificial vac on it to see it it opens all the way or not.

Also, check the pipe that runs from your turbo to your IC and look for leaks with soapy water. I would also pull that IC out and see if it's full of oil :o

Re: Low BoOst - Black Smoke under full throttle

Posted: Jun Tue 16, 2009 3:47 pm
by Mikewire
16490 - manifold/barometric pressure sensor (g71) f96 implausible signal
p0106 - 35 -10 intermittent
This sensor sits on top of your SMIC - check the wires cause they are fragile, and pull the sensor to see it is coated in oil and clean it with some MAF cleaner (get it at the auto parts store).

Re: Low BoOst - Black Smoke under full throttle

Posted: Jun Wed 17, 2009 12:40 am
by Dubber
It has been giving me these symptoms AFTER i installed the CAI - what does this mean do ya think??

i have not looked at my wastegate and rod/actuator i will research where those are and look at it. i should pull my intercooler and make sure its not full of oil - ill probably do that tom =)

Re: Low BoOst - Black Smoke under full throttle

Posted: Jun Wed 17, 2009 1:01 am
by Dubber
I am not sure if my knock sensor is bad- is that what that fault code is saying???

I also have again, yet again a multiple cylinder misfire on cylinders two and four...
i cant seem to get away from them!!

Re: Low BoOst - Black Smoke under full throttle

Posted: Jun Wed 17, 2009 3:13 pm
by Dubber
I unhooked my MAF and now the car does not smoke at all once its unplugged
so i will clean that and see what happens =)

Re: Low BoOst - Black Smoke under full throttle

Posted: Jun Thu 18, 2009 10:16 am
by DynoJetta
You should maybe try the Cage Mod. (basically cleaning your MAF and then stuffing the connectors full of dielectric greatse) It'd might be worth a shot.

Re: Low BoOst - Black Smoke under full throttle

Posted: Jun Thu 18, 2009 11:21 am
by Dubber
i cleaned the sensor with electric parts cleaner - worked great- - no smoke anymore =) now just to find that boost leak...=)

Re: Low BoOst - Black Smoke under full throttle

Posted: Jun Thu 18, 2009 12:41 pm
by kompressorgolf
nice! :thumbsup: