Puff of smoke mystery solved

[Hefeweizen]

A while back I posted an issue that I had with an occasional puff of smoke that I was trying to explain. The puff did not happen all the time, mostly during warmer weather after sitting at a light for a while. The other day, while I was under the car replacing the fuel line between the fuel pump and the fuel filter I discovered that the CV boot was cracked. All of a sudden it became clear to me what happened. During warm weather the grease was warmer and from the heat of the exhaust got warmed up to the point that grease dripped on the exhaust thus creating the smoke that just lingered under the car and manifested when I drove off. Eventually the puff would have stopped once there was no more grease in the CV boot

[GRNSHRK]

This is actually quite the interesting story Rainer

Surely you have more work to do, however

Eventually the puff would have stopped once there was no more grease in the CV boot

I surmise this is your next project

[Hefeweizen]

Yes, this is indeed my next project. I wanted to do that last Saturday already but the O2 Sensors of my wife's Toyota wore me out. That was another one of those jobs where you need to be a graduate of basket weaving 101. Who in his right mind puts 3 sensors in? Good thing we have extra output shafts so I can do some work ahead and just swap them out. This sure was a crazy thing though!

[Hefeweizen]

A while back I posted an issue that I had with an occasional puff of smoke that I was trying to explain. The puff did not happen all the time, mostly during warmer weather after sitting at a light for a while. The other day, while I was under the car replacing the fuel line between the fuel pump and the fuel filter I discovered that the CV boot was cracked. All of a sudden it became clear to me what happened. During warm weather the grease was warmer and from the heat of the exhaust got warmed up to the point that grease dripped on the exhaust thus creating the smoke that just lingered under the car and manifested when I drove off. Eventually the puff would have stopped once there was no more grease in the CV boot

This diagnose was wrong! Easy explanation but wrong! I noticed the other day that the puff of smoke happens when I am standing at a light and the rpm drops for some reason. No idea what causes the drop in rpm (not by much but it drops between 200 and 400 rmp real short). I suspect a connection to the injectors maybe? I am ruling out the injectors since I had them overhauled by witch hunters.

[tschultz]

Valve guides?