Smokes like a Duramax at WOT

[VASTREETRACER]

So for some time now I have had a smoking issue at 1/2 - wide open throttle. Been to the tuner several times and on the dyno everything looks good, but when I get out on the street you would think I did a Duramax swap for about the first second or 2 at WOT. This weekend I found where the vacuum line that runs from my booster pump to my blower had gotten hot (it's ran behind a heat shield but close to the bottom of my headers), and had enough cracks in it that it fell apart in my hand when I touched it. I ordered a new line from Whipple and it will be here Friday. My question is could this have been my problem the entire time or do I have some other issue I still need to chase? I know I'll find out for sure this weekend but anyone have any thoughts on this?

[cc-rider]

Tell us more about where this tube originates and ends? Could be something simple like that...could be half a piston gone and burning a cup of oil every time you give it the full potatoes.

[patternpilot]

I have a whipple and I don't have any vacuum lines close to my headers. By booster pump, are you referring to the brake vacuum booster? If so I ran that line along my fuel rail. Not as clean as it being hidden but not close to destructive forces.

[QUICRNU]

I do not believe the booster has anything oil related that could be burning, so unless it was sucking oil leaking from somewhere else into that tube, I am not sure how that could be the issue.

It sounds like only under load you are getting this smoke? Meaning possibly in the lower RPMs or "Luging" part of the RPM range? Does it happen the same if you are at 3000rpm and then go over 50% throttle vs at like 1600rpm and then over 50%?

I am curious if you have A/F gauge and what it reads during this.

Also what color is the smoke? White, Blue, Black ? I am assuming BLACK clouds that you cant see through since you referenced Duramax?

[VASTREETRACER]

I don't have an air fuel gauge. Yes even I'm at say 3k rpm and then go wide open it still does it. I'm 99% sure it's a fuel issue since it is black smoke and I've had friends behind me that say the smell of fuel will choke them out. If I can I will try and get a video of it today and post it.

The vacuum line I'm referring to runs from the msd boost a pump in the trunk up to my blower. It's routed under the passenger side of the car from the trunk up to I believe a vacuum port on the blower. I did 99% of the Install myself but couldn't get under the car to run that due to knee surgery I had 3 days prior.

[VASTREETRACER]

It's the vacuum line in this diagram from Whipple

[Trob85]

for sure fix that hose and see if that helps. However since it's fuel related I would start looking internally for faults. First check the plugs if it's that bad I would say the spark plugs would give a for sure indication of the problem cylinder. If you can find the problem cylinder or cylinders narrowing it down is the easy part. If the plugs are bad change them. If the plugs seem to be in good shape you might have a bad injector dumping fuel when it's not supposed to, that a cleaning might fix if not you might just need a new injector. Worst case sceniero you might have a valve not closing but that would be the last thing if you can't find any other issues. Fuel isn't as hard to diagnose as oil smoke it just takes some of your time to figure it out. Now I don't know what you've done to the car, how many miles, or what kind of beating you've put on it. If the components are new or 50,000 miles, did you buy anything used and what are some of the parts on your setup? Post some of that info if you could.

[cc-rider]

Ok. I see what hose you are talking about now. That's the hose that runs between your hobbs switch and the boost-a-pump. A hobbs switch is a simple switch that turns on and off via a boost signal. Its plumbed into your Whipple, and when you go into boost, it tells your boost-a-pump to turn on. So if its frayed and has a hole in it, then your boost-a-pump is not turning on and helping to push more fuel to the injectors like it should.

All that being said...I see in your sig that you have an ZL1 pump so I really don't think that the BAP is really all that critical. And since you have black smoke billowing out, that would indicate a rich condition if it were fuel related...not lean. But all things considered, you should get a new tube in there and make sure your BAP is working.

You may have a piston or 2 that's down and out. Billowing black smoke under power is either rich on fuel...or burning oil.

[Elite Engineering]

What do you have for a crankcase evacuation system? That is one of the most critical things to address properly after fixing the vacuum line routing.

[VASTREETRACER]

yes I have a zl1 pump and adm fpcm. I have changed plugs several times, they always look pretty good. Probably the oddest thing is on the dyno its fine, perfect AF, no smoke nothing, runs great. the second its on the street and I punch it you would thing I had a duramax for the first second or so. Friends behind me say the car will choke you out .

Elite Engineering I am running a catch can (not sure who makes it though), it vents from my drivers side valve cover to the port on the catch can and then to the port on the whipple. I also have a breather cap with a ball where my oil fill is.

The car has 160K miles on it now, I have been fighting this issue since about 80k-100k miles, changing plugs every 20k miles, been to 2 different tuners both are reliable well know tuners but cant seem to figure out whats causing this issue. Its not through out the entire RPM band just on the initial hit from what the people behind me are telling me. I will try this afternoon to get a video of it and post it. Just got the tracking from Whipple and replacement parts will be here Friday

[VASTREETRACER]

Originally Posted by Trob85

Now I don't know what you've done to the car, how many miles, or what kind of beating you've put on it. If the components are new or 50,000 miles, did you buy anything used and what are some of the parts on your setup? Post some of that info if you could.

I have 160k miles on the car. I installed the blower, first cam, headers, cold air at about 30k miles (all new parts). I installed the current cam (had about 4k miles on it) and upgraded to a 10 rib at 100k miles. I daily drive the car 120 miles each day, it sees very little track time and very little street play. I will be upgrading to either a LQ9 408 or LS3 418 this spring and im sure track time will increase after that

[VASTREETRACER]

I am looking at getting the N-Gauge to data log with. Anyone have any experience with this?

[VASTREETRACER]

Here ya go I was rolling and punched it at about 2500-3000 rpm

[VASTREETRACER]

cant get the video to upload. it smokes like this every initial hit, this includes shift points when I hit the gas again