Good Quality Oil Pressure Sender?

[chaskuss]

Before anyone spends money on new senders here is a quick and easy way to see if it's a ground continuity issue. First using Scotch-Brite or similar clean an area on the hex section of your VDO sending unit. Strip a piece of wire so that you have half an inch of bare copper wire exposed. Using a mini hose clamp, temporarily clamp the bare section of the wire to the cleaned area of the sending unit. Run the other end of your new ground wire either to your Forest of tabs ground or directly to the EIS unit. If the problem goes away, you know it's not the internals of the sending unit. It's a mechanical ground issue. If this doesn't improve it, well you need new sending unit anyway.

Charlie

[Kooshball]

Originally Posted by chaskuss

Before anyone spends money on new senders here is a quick and easy way to see if it's a ground continuity issue. First using Scotch-Brite or similar clean an area on the hex section of your VDO sending unit. Strip a piece of wire so that you have half an inch of bare copper wire exposed. Using a mini hose clamp, temporarily clamp the bare section of the wire to the cleaned area of the sending unit. Run the other end of your new ground wire either to your Forest of tabs ground or directly to the EIS unit. If the problem goes away, you know it's not the internals of the sending unit. It's a mechanical ground issue. If this doesn't improve it, well you need new sending unit anyway.

Charlie

In my case it is a mechanical failure on the sender...plenty of oil leaking out the back where the terminal is.

[Maxrate]

We were chasing oil pressure fluctuations recently. An old timer on the field gave us a gauge setup to temporarily attach direct to the oil pressure fitting. We were able to read actual oil pressure on the gauge to verify what the sender was reading. That allowed us to determine a bad ground causing the problem. Also, we we?re using a VDO.

[chaskuss]

Originally Posted by Maxrate

We were chasing oil pressure fluctuations recently. An old timer on the field gave us a gauge setup to temporarily attach direct to the oil pressure fitting. We were able to read actual oil pressure on the gauge to verify what the sender was reading. That allowed us to determine a bad ground causing the problem. Also, we we?re using a VDO.

Mark,
Are you using the one wire VDO senders as supplied by Grand Rapids? Or are you using 2 wire VDO senders which provide a dedicated ground wire?

Charlie

[Maxrate]

Here you go Charlie. I suspect the paint on the original surface gave erroneous indications. Once we grounded it to the firewall our readings came in line with the manual oil pressure gauge we had directly hooked up.
https://www.aircraftspruce.com/catal...lickkey=200876

[chaskuss]

Mark,
I'm glad to hear it's a simple fix.

Charlie

[Kooshball]

Is there any reason to believe that putting compressed air (rather than oil) on the sender in order to verify the calibration curve would cause any problems?

[Canadian_JOY]

Originally Posted by Kooshball

Is there any reason to believe that putting compressed air (rather than oil) on the sender in order to verify the calibration curve would cause any problems?

Compressed air works just fine, as does nitrogen. Just be very careful in terms of pressure regulation as one does not want to expose the sender to over-pressure situations or large/rapid pressure transients.

[chaskuss]

Originally Posted by moosepileit

Is there a Kavlico option with A GRT EIS?
snipped.

Rich, GRT does not offer Kavlico transducers as an option at this point in time. However I got off the phone with Eric at GRT earlier this morning. I explained to him the basic parameters of the Kavlico P4056 series transducers. He assured me that they can be made to function using the six auxiliary inputs that the EIS 4000 + 6000 give you. It's a simple matter of inputting the correct offset in the software so that the transducers will be accurate. I've sent him my serial number and software version and the datasheet for the Kavlico transducers that I would be interested in using. Once he reviews the information he will contact me and give me the offset that I need. Anyone else wanting to use the sensors would have to pick the exact sensor they want to use and then contact GRT support. You'll need to supply the exact Kavlico sensor info, your serial number and the software version that your unit has. It all makes a difference.

Charlie

[moosepileit]

Sounds good, thank you, Charlie!