Black splatters when cold

[t-west]

Hi all,

When I first start my car, it idles rough, even with the choke activated. Additionally, and the real problem for my SWMBO is that black splatters out of my exhaust pipe. It smells like neither oil nor gas. It didn't used to do this:

I recently tuned the carb (5200), which was running rich, and dropped the timing to a more acceptable level (about 18*). Problems started after this. No fouled plugs--in fact, they're white with a nice light brown tint in places.

When the car is warm it idles fine and no "liquid" seems to come out of the pipe. I'm wondering if condensation could be forming, carrying out carbon build up with it? Or if it is oil, why would it be so much worse when the car is cold?

Oh yeah, see my mods below. I'm running the "stock" Wells module but am considering upgrading to MSD, especially if it would clear this problem up.

thanks,
--tom

 

[XFlow_Fairlane]

sounds like classic condensationg carrying out carbon. when cold this is more common from the choke being richer. you might need to lean your choke out some.

 

[mustang6]

When the car is warm it idles fine and no "liquid" seems to come out of the pipe. I'm wondering if condensation could be forming, carrying out carbon build up with it? Or if it is oil, why would it be so much worse when the car is cold?

I believe that is exactly what's happening- the inside of your exhaust is coated with carbon byproducts from running so rich and now the condensation tht forms in exhaust systems (especially during wetter, cooler times of the year) is spitting some of it out the exhaust when you first start it up. The only way I know how to instantly clean an exhaust system out is to disconnect the pipes and blast them out with a pressure washer (watch out for the huge blasts of black crud at the other end when you do this!). Or if you've truly corrected the rich condition as you say this problem will ease over time as the soot gets washed out of the pipes a little at a time by the condensation.

 

[t-west]

Can I blast with a pressure washer from the exhaust manifold on back without ruining anything, like the muffler?

--tom

 

[XFlow_Fairlane]

do you drive the car alot? reason I ask is that before my 5200 I ran WAY rich all the time. ran the lean jetted 5200 for 2 months and my exhaust was SPOTLESS inside...no carbon at all. I say just drive the car ont eh highway a little

 

[t-west]

I drive about 100 miles/week, and I'd rather not blacken my garage floor until it clears out. I have to pull the exhaust man. anyway to replace the gasket. I may try to stick a pressure washer in there to flush it out, then blow it with my blower to get as much water out as I can.

--tom