Special Service Tools

The Diacom Marine program from Rinda Technologies can be used with many of the competitors engines as well as Volvo Penta’s engines. You can view and capture data that can be emailed later to the factory. The service manual is built right in and the codes display what they mean instead of just a code number (as with the winky-blinkie).

The above graph shows a start cycle for an engine with a drivability complaint of hesitation on acceleration.

During starting the voltage drop to 9.8 volts (or slightly lower) due to incorrect battery capacity, type or state of charge. This low voltage causes the ECM’s processor to shut down momentarily. Once the voltage rises again, the ECM “wakes up”and rereads baro while the engine is cranking over. This causes the barometric pressure (derived from the MAP reading) to be read while there is vacuum in the intake. In this example that causes the baro to change by 2 inches of mercury. This effectively tells the engine it is at altitude and reduces the amount of fuel to be delivered accordingly. So the engine will run lean until the baro gets updated and corrected (at WOT). You can see in the bottom graph that the engine RPM dips slightly during acceleration as a result.

During a restart with a warm engine the barometric pressure remained at 29.2 inches and the hesitation was no longer present.