Black exhaust smoke upon startup???

[Chaz]

Just noticed recently black smoke out of the tailpipe upon startup on my 89 350tbi,,,,,,its not constant,,,,it goes away real quick after startup but its starting to occur more and more frequently,,,,,bad valve seals or is it prob fuel system related???

 

[smurph20]

Black smoke is burning rich. If it were blue then id say oil.

 

[Jims86]

Check for drops from the injectors. gander at them while someone cycles the key on and off, waiting 12 seconds between each cycle. do not go to the start position. If you see fuel, you need a throttle body rebuild kit. round $45 for a good one.

 

[Chaz]

Its got a holley 670 tbi unit on there,,,,bout a year old,,,,,you guys helped me fix engine probs on it before,,,,it was idling poor and found out it was the msd coil when I replaced it with stock one,,,,,no problems since until the black smoke im gettin now,,,but ill check the injectors and see anything looks different than before thanks Jim,,,,

 

[GreaseDog]

Probably the throttle body. Those things are known to cause problems right out of the box.