MP Fluctuation

[cknauf]

Finally flying and finding it difficult to determine the average of rapid MP fluctuations up to 2" in magnitude. Engine to battery neg reads 0.6 Ohm so I'm ruling out a bad ground.

 

[PhantomPholly]

This is a standard problem. The issue is the pulsing of the intake. Since the only thing you care about is average MP, all you need to do is put a restriction between the source and the sensor.

Some people have simply installed a cigarette filter in the tube - but this is not recommended, because some have found later that the filter is no longer there (the fibers got sucked through the engine). Best answer is a diaphragm with a pinhole in it inserted at one of the line couplings.

 

[Daffy]

I have done just that, works a treat, A small thin soft aluminium disc inserted into the hose end and clamped down forms a cone, then a small drill hole, Voila!!!

 

[Roger_Lee]

Many of us just use a Bing Idle jet. It has a small hole in the center, it is a perfect fit in the hose line and makes the MAP steady as a rock. Mines been that way for 3.5 years. I did put a wire tie around the hose on top of the jet. Nothing can go down the line and its ready made.