Queens94z28

I put the motor together last year and had the car dyno tuned. It was running great all last summer and this year I have been dealing with smoke when I go into PE mode or WOT. I get no smoke when driving normally. The smoke is very dark when it happens and leads me to beleive the car is rich at WOT. I dont smell oil burning.

I fixed what appeared to be an exhaust leak after the O2 sensors early this summer where my y pipe joins the cat. Also added a racetronix fuel system at the same time. I run a fuel pressure gauge in the car and my pressures havent really changed but I guess the car might be seeing higher pressure at WOT than it did with the old stock fuel pump. Cant verify that though.

I have driven with a scanner hooked up and the O2 sensors are cycling as normal. I had my header recoated last year, could that have scewed the O2 sensors?

I installed a catch can in the pcv this year and it only has a few drops of oil in it. I dont get any smoke out of the oil fill to indicate blowby and compression tests were normal. I did a leakdown test on a couple of cylinders that I could easily get to and it indicated 5%. I will be doing the remaining cylinder when I swap to kooks over the winter.

The engine has about 1,000 miles on it and looks to be in great shape. Do you think this could just be a tuning issue or do I need to dig deeper here. Im stumped because I only get smoke at WOT, and didnt before.

Can the car burn oil at wot only? I would think if I had a bad ring, it would smoke all the time and it would stink of it.


Thanks for the help in advance.

Guest47904

First of all, you have to get rid of one or the other in your mind. Light white/blue smoke is oil. Dark black smoke is fuel. Normally if you had an oil burning situation, it would occur more than just at WOT. So I think you have a normal pig rich situation at WOT and is normal but lets' talk about it.

If you want to see if you are running rich all the time, not just at WOT. Be sure the plugs are clean and run it for a few days and stay OUT of WOT. Then recheck the plugs to see if they are sooted up.

Then depending on those results, you may want to try a few WOT pulls and recheck them. Remember, computer goes away from closed loop control when you floor it.

In the mean time, you could also monitor your fuel economy.

Queens94z28

Thanks. I pulled the plugs and they appeared normal with a brown/gold color. I see your point on the oil burning, I dont think I have a problem there. The smoke is definitely dark.

The car is burning a lot of gas, I dont drive it much but it is a bit of a pig. Im getting about 150 miles to a tank with mixed spirited driving and a little cruising.

I think I need to get back to the tuner.

speed_demon24

Puffs of black smoke = detonation. Is it constant or a trail of black smoke?

96capricemgr

If the car is downing that much fuel under normal driving and you have black smoke at WOT I would expect serious engine damage quickly.
You could check fuel pressure with a regular gauge for starters.