Is my soft start working properly?

Walt Asked:
I have occasionally used a different starting technique where I crank with the ignition switched off and after 2 prop revolutions turn them on. ...  Am I doing any harm doing this?

I do not see any problem with that procedure.

The serial number on the modules shows that your system has the soft start circuit inside (started in 2010)  The first 2 digits are the year of production and the balance the serial within that year.  Be sure that you have power to the modules from your relay to activate/excite the circuit otherwise it simple shifts from start timing to run at 650 to 1000 RPM.  

Cheers

RFSC wrote: Be sure that you have power to the modules from your relay to activate/excite the circuit otherwise it simple shifts from start timing to run at 650 to 1000 RPM.  

Can you explain more. How do I check if this is connected properly?

I believe that to engage the soft-start circuit you need to apply 12V to the violet wire on the ignition module 6 pin connector during cranking. I assume that people usually take a feed from the starter solenoid coil (not the main contact). Take a look at figure 74-20 in the 912 heavy maintenance manual. I've attached a screen shot of the figure where I have arrowed the connections. A resistance continuity check to these pins from the starter circuit should tell you whether they are connected.

Kevin Stewart wrote:

I believe that to engage the soft-start circuit you need to apply 12V to the violet wire on the ignition module 6 pin connector during cranking. I assume that people usually take a feed from the starter solenoid coil (not the main contact). Take a look at figure 74-20 in the 912 heavy maintenance manual. I've attached a screen shot of the figure where I have arrowed the connections. A resistance continuity check to these pins from the starter circuit should tell you whether they are connected.

 Kevin,

I finally dug into it. The purple wire coming from the module, well, you need to use your imagination to say its purple, anyway it did not have continuity to the wire on the starter which made it harder to believe it was purple. The other module connector was harder to get to but I finally opened it and the wire in the same position DID have continuity to the starter wire. It turned out the other purple wire had a loose crimp and was sitting in position with no contact. I had one module doing soft start and the other wasn't.

I reconnected the bad one and it starts like a champ, slightly rough for 5-6 seconds then a RPM increase and smooth.

Thank's everyone who offered help to troubleshoot my problem.