High pressure reading one more time

I know this subject has been beaten to death, but its just happened to me. Original pump, original fuel pressure sender, Dynon 5.3 version, 149 hours. Just completed the Condition inspection, no hint of fuel pump leaking (the foam tie-wrapped under the weep hole is intact). During the inspection I opened the 4 spade connectors in front of the firewall (I think two of them are for the sensor) cleaned them with Deroxit, and put them back together tightly. Same for the 4 spade connectors at the Red Cube. Cleaned the gascolator-- nothing there. Just 1 hour into the post-inspection check flight I got the high fuel pressure alarm-- about 5.7-5,8 psi. Pressure check at idle and 4000 RPM before takeoff was normal-- high 4-low 5 psi. Pulling the power back dropped pressure for about a minute, then it built up to alarm values again. Continued to "silence" the alarm and it continued to go off every 30 seconds-- very irritating to say the least! Even went off on short final with power at idle. On the ground I pulled the electric fuel pump fuse and the reading dropped to about 4.3 and stayed there regardless of engine RPM.

I've read the archives and will switch to ring connectors but have a feeling I'm in for a new sensor. Really, REALLY don't want to do that as I'm virtually computer illiterate and have never been able to load anything on my Dynon. I could download the files onto my PC and put them on a CD for the laptop, but getting then from there into the Dynon is most likely going to screw something up big time. Not to mention that I don't have a clue about "locked files"!

Any other suggestions besides just disabling the alarm? Never had another airplane with a fuel pressure reading nor one with both an engine-driven and full-time electric pump, so this seems like too much information to me.

THANKS

Wayne 120241

I had the exact same situation. Mr. Kavlico fixed it.

Had the same problem on first flight. Changed to ring connectors and have had no problem since.

You may have seen my posts concerning a recurring high fuel pressure warning. At this point I've tried everything (Kavlico, with the required firmware update, ring terminals, rerouting signal & ground wires directly to the EMS 37 pin d-sub, etc., etc.) all to no avail. Now I've just completed an email to Dynon to get a RMA so I can send the D180 back to them.

I've had a highly qualified ex-electronic company owner working with me and we've tried everything. The only thing that HAS worked was to wire a
220 ohm 1/2w resistor across the terminals of the VDO sensor. Now the
fuel pressure stays in the green all the time, from idle to WOT, with or without the boost pump on. But this is only a last gasp measure, I'd sure as heck like to get the Dynon working like it's supposed to.

By the way, in my opinion, the Kavlico is, at least for me, not the answer. I used the VDO for years in my RV-8 and 8A without an issue. To me, there is just something going on with some of the D180's that casues problems.

Walt Shipley

Ring terminals

Seem to have worked. Only have 2 flights since changing them (0.5 and 1.1 hours) but no alarms and rock-steady pressure readings. I'd recommend that those in the build process change them now-- it's a lot easier, especially if you've moved the oil sensor to the same mounting screw on the firewall!

Thanks guys!

Wayne 120241/143WM

Plugged orifice

Walt, check the return line bayonet fitting . There is an orifice screwed into it and is accessible only by removing the return line. I found mine plugged after experiencing a fuel pump failure. You can clear it wth a fine sewing needle. The orifice is what establishes fuel line pressure.

Jersey

yankee-flyer said:

Seem to have worked. Only have 2 flights since changing them (0.5 and 1.1 hours) but no alarms and rock-steady pressure readings. I'd recommend that those in the build process change them now-- it's a lot easier, especially if you've moved the oil sensor to the same mounting screw on the firewall!

Thanks guys!

Wayne 120241/143WM

Click to expand...

Keep in mind that even ring terminals are crimped on connectors.
Poor crimps causes more problems than anything..
It is very possible that many of these problems get fixed by changing connectors, because the new connector are installed very carefully, thus being the actual reason for solving the problem.

Very, VERY possible

and I think I learned a lot about crimping terminals, doubling over small wires, etc, since I attached those spade clips. That said, the spades are in an environment where that's a lot of potential vibration and have a free span (not tied to anything) for several inches. And I'd pulled and cleaned all the other spade connectors during the CI-- maybe they got jealous because of lack of attention?? But I do feel better about the ring terminals and it's an easy fix. Glad I tried that first before ordering the Kavlico.
Wayne 120241/143WM