fuel mixture adjustments

[arcijack]

guys need your help again, drove my car sunday several times around the block angering my neighbors because i have no muffler or cats on car, drove like a bat out of hell on a couple ocassions, but upon entering drive way car stumbled and sputtered, emitts white smoke and quit, would not start , could smell a very distinct fuel smell, almost like kerosene, i adjusted mixture screw, and she fired up. i've had to do this on more than 1 ocassion, seems as if the mixture cannot find a sweet spot,,,,one minute its lean the next its rich, constantly having to fiddle with mixture screw and idle screw. what could be causing this problems?

 

[Helmet]

What model are we talking about ?

 

[260ebenz]

450SEL 6.9 W116 Peter.

 

[arcijack]

yes. its a 6.9

 

[Helmet]

Once set when the engine is at operating temperature the settings should not change. Is the pivot for the air flow sensor free (not binding). Can you confirm that control pressure is constant when engine is hot ?

 

[arcijack]

i will check control pressure this weekend, i was told by a local mechanic, that it sounded like my return line inside the fuel tnk was stopped up, the tank had a lot of scaled and rust, we had it cleaned and sealed, but he believe the sealer or scaled is lodge in line near the swirl pot in tank, this problem happens when the tank is very low on fuel.

 

[arcijack]

drove the car today running good, timing was a little off, but done well, i still think gas tank swirl pot is clogged, as long as i keep a half of tank of gas , no problem, i'm going to pulled tank off and have a professional here cut it open and reweld, he says he can make a pot if need be.

 

[Helmet]

drove the car today running good, timing was a little off, but done well, i still think gas tank swirl pot is clogged, as long as i keep a half of tank of gas , no problem, i'm going to pulled tank off and have a professional here cut it open and reweld, he says he can make a pot if need be.

Have you checked the strainer in the tank ?