Manifold/lambda problems

[gjuro]

Recently I installed new, custom made 4-2-1 manifold. After driving the car for few days, it doesn't work properly between 2-3k rpm when accelarating.

Could this malfunction be due to the fact that lambda is reading only 1 cylinder readings? Did anyone had similar problems?

Btw, engine is Blacktop 20V

[irishtwincam]

Hey you have a leekun engnie

Its always better to get lambda from the common pie to all 4 cylinders.

[jondee86]

Certainly... better to sample from the collector. But, there are any
number of aftermarket headers coming from Japan with the sensor
mounted in one of the primary tubes.

If it is a one wire or two wire sensor (non-heated) the end of the
sensor may need to be further into the gas stream. Does the end of
the sensor project out into the gas stream by the same amount as
when mounted in the factory location ??

Blacktop engines are well known for a mysterious mid-range stumble.
Sometimes a new sensor solves the problem.

Cheers... jondee86