96 Legacy GT

[majorpainnz]

I've heard some ppl have had this problem with their legacy's but no
one seems to know why it does it and my knowledge of cars isn't that
great.
After driving the legacy around for a while the car seems to lose power
and run rich for a period of time and makes a plume of black smoke out
the exhaust, the car just does this randomly when it wants to. and one
of the turbos seems to make a vacuum noise at random intervals of
accelerating and then disappear. Can anyone help with the problem?

 

[Lenny]

Hi,

I'm no expert but the problem sounds like the turbo could be sticking when warm. This may cause the rich mixture because the ECU may be injecting enough fuel for turbo assisted air flow?

Lenny

 

[Mike]

My Pick would be a knock sensor playing up.
The only time I have have seriously rich mixture that black smoke is when I
accedently used low grade petrol and I was accelerating hard. That time I
could hear the engine detinating.(knocking) If you have a faulty sensor (or
poor ground connection) it could be doing the same
Mike

 

[Carl 1 Lucky Texan]

I've heard some ppl have had this problem with their legacy's but no
one seems to know why it does it and my knowledge of cars isn't that
great.
After driving the legacy around for a while the car seems to lose power
and run rich for a period of time and makes a plume of black smoke out
the exhaust, the car just does this randomly when it wants to. and one
of the turbos seems to make a vacuum noise at random intervals of
accelerating and then disappear. Can anyone help with the problem?

I'd say possibly a bad MAF. $$$$ - sometimes carefully cleaning the
element with alcohol will fix it. Do you run an oiled panel filter - K&N
style? - sometimes the oil from those will destroy/confuse a MAF.

I dunno


Carl