Fuel Pressure Crazy-High

[Ed_B]

I have an EMS in my RV. About a month ago the fuel pressure started reading 9-11psi in flight instead of the normal 6ish. I don't think it's even possible to get that kind of pressure out of an engine driven pump/carb setup.

Thinking this must be a sender problem, I hooked up the still installed mechanical fuel pressure gauge and the pressure reads 6psi during flight, but the (unhooked) EMS sender was now showing 3-5psi on the EMS. Hmmm, apparently the electric sender is "adding" 3-5psi to the actual reading? Is this possible? :-/

I assume the sender is not adjustable, do I need a new one?

 

[dynonsupport]

Ed,
That does sound like a damaged sensor. I assume when you say it's "unhooked" you mean it's still wired to the EMS, but the pressure port is just exposed to the atmosphere instead of the fuel line? Is it still grounded when you do this?

It is possible for the sender to "add" to the reading. It's actually a mechanical lever inside moving a variable resistor, so things can get bent/twisted/dirty and act like you are seeing.

The sender is not adjustable.

 

[Ed_B]

Yes, the sender is still electrically hooked to the EMS, but the port is exposed to the atmosphere.

The EMS is under warranty, can you send me another sender, or do I need to RMA the old one first, or?

Thanks.

 

[dynonsupport]

One quick sanity check we can do remotely: With the sensor disconnected and the unit powered off, what is the resistance across the sender? Also, is this the carburetted or fuel injected sensor?