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Lasar - Engine starting problem...

ricwan

I'm New Here
Dear all RV folks...

I have intermittent problems starting the engine and would like to ask for advice.

Lasar ?light? does stay illuminated during crank and by that the system does not fire the "extra spark" for ignition.
I have connected the cable and all data displayed is normal, key position, manifold pressure, rpm, voltage normal ? and no fault code.
Only thing that helps to ?reset? the controller by connecting/disconnecting the cable-harness from the controller ? then it starts again.
Same problem happens occasionally about after 5 flights? solution is again reconnect the cable and it works directly.

I would like to ask you for advice of what we can try to find,

Best Regards,
Rickard Wanderydz
 
Rickard,

I don?t think your ?reset? procedure is really doing anything to reset the controller. I think what is happening is the electrical bus voltage during initial engine cranking is dropping low enough, long enough that the Lasar controller cannot fire the spark, thus the light staying on. In normal operation the light should go out after a few blades, and the engine fires up.

This has occasionally happened to me when the battery has been cold soaked, or the plane has not been flown in the last couple of weeks. My modified starting procedure is to pull the Lasar circuit breaker, start cranking the engine, and after a revolution or two push the breaker in. This gets past the initial bus voltage drop. It has worked every time to start the engine. Well, every time except for a few days ago when my 6 year old Odyssey battery finally gave up and the engine would not start. One new starter battery later everything worked again, without pulling the breaker. :)

A permanent fix for this starting problem is to install one of these: http://www.tcwtech.com/IPS_12v_intelligent_power_stabilizer.html
 
I agree with Steve's diagnosis, although my fix was different. My previous RV-8 has the Lasar system and I had the same issue and used the same "pull the Lasar CB for a couple of blades and then push it back in" fix for a few years.

My fix was to get rid of the SkyTec 149-12LS permanent magnet starter that was on the RV-8 and I replaced it with a Hartzell X-Drive starter (Model SRZ-9021). That solved the problem and I no longer had to pull/push the Lasar CB during the start.

Although the Hartzell X-Drive starter is also a permanent magnet starter, it was advertised to have a low inrush current draw, and it has worked well with the Lasar system.

It is very common for the starter to pull the voltage low enough that the LASAR will not fire. When the battery is still good but has lost capacity, this will happen.
 
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Rickard,


A permanent fix for this starting problem is to install one of these: http://www.tcwtech.com/IPS_12v_intelligent_power_stabilizer.html

Good idea. Also Earth X sells an affordable portable boost lithium pack with leads. You install the leads on the battery then just plug in for a big boost during start up.
Probably those 2 things will cure your problem for the least amount of hassle and effort.

If not I have a complete working lasar system if interested
 
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