Manifold Pressure Gauge Error

[wilky10]

Does anyone know the tolerences for a Piper Seneca MAP gauges?

If the gauges are reading low when the engines are off then you would assume they are off when the engine is running. Why would the engines appear to run normaly (book numbers) in flight?

 

[ackattacker]

They are BOTH reading low? By the same amount?

Not to point out the obvious, but are you accounting for current pressure altitude at your airport?

 

[wilky10]

Yes, they are off by 5.5 from altimeter. I am at 2600" (DA 2750") elevation, so that means they are still off by 2.8".

 

[ackattacker]

I see from your other posts that it appears you are talking about an Avidyne system.

I have never seen a problem like you describe on a regular old mechanical MAP guage. I have seen them stick but that's it.

If you are talking about the Avidyne system then it is likely they have a calibration somewhere in the software.... way beyond my area of knowledge. Sorry. The cynical answer is that an unscrupulous person dialled back the calibration so as to hide an over boost at full power. I would hook a proper pressure guage into the system and run it up on the tie-down.

 

[avbug]

What are the specific numbers you're seeing? Which Seneca, which turbo system? Which wastegate--which overboost protection?

Providing details is helpful.