Fuel Pressure reading

[davemgill]

I have finally wired up the oil and fuel pressure sensors. The oil pressure is okay and reads zero. However the fuel pressure (Injected version) reads 5 - 6 psi when there is no pressure in the system. I haven't got the rest of the fuel system sorted out yet so I can't test under pressure. It doesn't seem to be an earth problem as there is virtually no resistance between the sensor housing and the EMS earth. There is a resistance across the sensor body and the output terminal but on the oil pressure there is no resistance. Any Ideas?

David

 

[dynonsupport]

Make sure that the correct fuel pressure sensor type is selected in the EMS sensor configuration. The fuel injected sensor (p/n 100411-001) is type 2.

Additionally, what is the exact resistance that you are measuring on the the fuel pressure sensor?

 

[davemgill]

Yes, I've got Type 2 set.

The resistance is 7.8ohms. With the EMS on the voltage from GND to the sensor terminal is 0.193v and 5.5psi is showing on the EMS. With sensor type 1 it shows 2psi.

I tried with the sensor wire disconnected or connected and there is no difference in the resistance.

Regards
David

 

[dynonsupport]

A few more tests to try:

With the wire disconnected, the pressure should read 99.9 PSI.

Shorted to ground, the pressure should read 0.0 PSI.

If it still reads some pressure when shorted to ground, try moving the grounding point as close to the EMS as possible. This will tell us if it is a potential difference between the EMS and your ground, or the EMS itself.

Also, feel free to call us while you are out trying things at the plane and we can see if we can diagnose it quicker.

 

[davemgill]

That all works okay, 99.9 with it disconnected and 0.0 with it connected to the sensor body. If I get a chance I'll give you a call tomorrow to discuss.

Regards
David

 

[Ray Doerr(Guest)]

Any idea why my EMS-10 would be reading Fuel Pressure in the low range at around 15 psi with the engine drive pump pump and then 18 psi with the electric fuel pump on a IO-540 engine while others with the identical engine and pump are ready 25 - 35 psi with there EIS engine monitors? I have the type 2 sensor for the injected engine. I first had the sensor type set to type 1 which would then read only 6 psi, I corrected that and now it only reading 15 psi with engine drive pump which is almost the minimum from the pump manufacturer.

Thanks Ray
(I'm slowing getting all these sensor corrected and setup properly)

 

[dynonsupport]

How does your oil pressure look? The oil pressure sender and the injected fuel pressure sender look virtually identical, except for the packaging that they come in and the markings stamped into nut head on the bottom of the sender. Look on the nut base that you'd grab to tighten the sensor down. On one of the faces, you should see a pressure range. 0-5 bar is the injected fuel pressure sender; 0-10 bar is the oil pressure sender. They output similar resistances, so if they were physically mixed up you'd expect to see low fuel pressure, but high oil pressure.

 

[e were you put tRay Doerr(Guest)]

The oil pressure and the fuel injected sender both say 0-10 bar on the side where you put the wrench to tighten them. Looks like the fuel injected pressure sender is the wrong one. Can you please send me the proper one to my address you have on file.


Thanks Ray.

 

[dynonsupport]

On it's way.