VM1000 Tachometer Speed

[DBentley]

I am putting this information into the system so it can help someone in the future, relative to out of production hardware modifications.

There is a subpopulation of RV owners who like myself originally installed LASAR electronic ignition and are now migrating back to P-magentos. If you have the VM1000 engine monitor, and are using their supplied Tach sensor, the new P-mag produces an rpm reading that is 1/2 what it used to be with the LASAR system installed.

Remove the VM1000 DPU and take off the back cover held on with the four counter sunk screws. With the circuit board oriented right side up (writing legible) there are four columns of very small pins in the center. You will see two column sets on the right and two on the left. There is a blue "jumper" fitted across one pair of each of the column sets, based on the configuration of your engine. On the LH side columns, you will find "V1-" identified in one row, and "V1+" below it. I was told by the Vision Microsystem rep to carefully pull off the blue jumper from the V1+ pair and attach it to the V1- pair.

It worked!

Duane Bentley
RV6
N515DB

 

[FredMagare]

Good Info...

Thanks. I have an older VM1000 (not the "C" model) and was rethinking my original Laser Ignition choice. (Nothing installed.)

On a side note - did you have any problems with the original installation of the monitor? With the VM1000 no longer being supported (according to earlier reports) I'm concerned about the installation. Any suggestions would be appreciated.

 

[DBentley]

VM100 Original Installation

Let's see, that was about 6-7 years ago. There is a template available that allows you to mark & cut a hole in the instrument panel to allow a very precise monitor and the screw holes location. I doubt that VM still offers it, and I don't think I still have mine. You might check around to others.

The installation went well as long as you take the time to think out each sensor and the location you want to install it for future access / interference, e.g. EGT probes - make sure you can access spark plugs; firewall installation point for transducers, etc. I did have a problem about 2 years after first flight, with an intermittent response on either the amperage or voltage reading. The VM tech staff in Bellingham, WA worked at length with me over the phone and finally asked me if there was any way that any of the connection points were being shorted. A couple of the firewall interface units they supply have open / uninsulated connections. After climbing under the instrument panel again, I found that some of the firewall aluminum foil used for heat reflection had come loose and was flapping agains the VM electrical points. I cut out a reasonable barrier around each, and it solved the problem

Duane

 

[FredMagare]

Thanks, Duane! I have the template you referred to. Other than the intermittent problem all was well?

 

[DBentley]

I have been very happy with its reliability. The fuel flow analyzer has been accurate withing a gallon every refill as well.

 

[TXav8r]

Let's see, that was about 6-7 years ago. There is a template available that allows you to mark & cut a hole in the instrument panel to allow a very precise monitor and the screw holes location. I doubt that VM still offers it, and I don't think I still have mine.

Duane

Vision still has them. Call 210-447-2446 and ask for Jack.