diff --git a/firmware/controllers/math/engine_math.cpp b/firmware/controllers/math/engine_math.cpp
index cce1e456f4..a3fa0ddcd8 100644
--- a/firmware/controllers/math/engine_math.cpp
+++ b/firmware/controllers/math/engine_math.cpp
@@ -189,8 +189,6 @@ void FuelSchedule::addFuelEvents(injection_mode_e mode DECLARE_ENGINE_PARAMETER_
 		return;
 	}
 
-	efiAssertVoid(!cisnan(engine->rpmCalculator.oneDegreeUs), "NAN one deg");
-
 	/**
 	 * injection phase is scheduled by injection end, so we need to step the angle back
 	 * for the duration of the injection
diff --git a/firmware/controllers/trigger/main_trigger_callback.cpp b/firmware/controllers/trigger/main_trigger_callback.cpp
index 1b15961678..a05c279ef9 100644
--- a/firmware/controllers/trigger/main_trigger_callback.cpp
+++ b/firmware/controllers/trigger/main_trigger_callback.cpp
@@ -211,7 +211,9 @@ static ALWAYS_INLINE void handleFuel(bool limitedFuel, uint32_t currentEventInde
 
 	for (int injEventIndex = 0; injEventIndex < injectionEvents->size; injEventIndex++) {
 		InjectionEvent *event = &injectionEvents->elements[injEventIndex];
-		if (event->injectionStart.eventIndex != currentEventIndex) {
+		uint32_t eventIndex = event->injectionStart.eventIndex;
+// todo fix bug & uncomment this		efiAssertVoid(eventIndex < ENGINE(triggerShape.getLength()), "handleFuel/event sch index");
+		if (eventIndex != currentEventIndex) {
 			continue;
 		}
 		handleFuelInjectionEvent(injEventIndex, limitedFuel, event, rpm PASS_ENGINE_PARAMETER);
diff --git a/firmware/controllers/trigger/rpm_calculator.cpp b/firmware/controllers/trigger/rpm_calculator.cpp
index 377c349151..dab4dc331e 100644
--- a/firmware/controllers/trigger/rpm_calculator.cpp
+++ b/firmware/controllers/trigger/rpm_calculator.cpp
@@ -71,6 +71,10 @@ bool RpmCalculator::isRunning(DECLARE_ENGINE_PARAMETER_F) {
 			return false;
 		}
 	}
+	if (lastRpmEventTimeNt == 0) {
+		// here we assume 64 bit time does not overflow, zero value is the default meaning no events so far
+		return false;
+	}
 	/**
 	 * note that the result of this subtraction could be negative, that would happen if
 	 * we have a trigger event between the time we've invoked 'getTimeNow' and here
diff --git a/unit_tests/engine_test_helper.cpp b/unit_tests/engine_test_helper.cpp
index 9bd1287c57..7183621894 100644
--- a/unit_tests/engine_test_helper.cpp
+++ b/unit_tests/engine_test_helper.cpp
@@ -87,6 +87,4 @@ void EngineTestHelper::applyTriggerShape() {
 	engine->triggerShape.initializeTriggerShape(NULL PASS_ENGINE_PARAMETER);
 
 	incrementGlobalConfigurationVersion();
-
-
 }
diff --git a/unit_tests/test_trigger_decoder.cpp b/unit_tests/test_trigger_decoder.cpp
index c2effead02..be0a4b3fa6 100644
--- a/unit_tests/test_trigger_decoder.cpp
+++ b/unit_tests/test_trigger_decoder.cpp
@@ -604,8 +604,14 @@ void testFuelSchedulerBug299(void) {
 
 	assertEqualsM("RPM=0", 0, eth.engine.rpmCalculator.getRpm(PASS_ENGINE_PARAMETER_F));
 
+	eth.fireTriggerEvents2(1, MS2US(20));
+	assertEqualsM("RPM#1", 0, eth.engine.rpmCalculator.getRpm(PASS_ENGINE_PARAMETER_F));
 
-	eth.fireTriggerEvents2(2, MS2US(20));
+	eth.fireTriggerEvents2(1, MS2US(20));
+
+	assertEqualsM("RPM#2", 3000, eth.engine.rpmCalculator.getRpm(PASS_ENGINE_PARAMETER_F));
+//	// this is needed to apply new fuel schedule, we can only do that once we have RPM
+//	engine->periodicFastCallback(PASS_ENGINE_PARAMETER_F);
 
 	schedulingQueue.executeAll(99999999); // this is needed to clear 'isScheduled' flag
 	engine->iHead = NULL; // let's drop whatever was scheduled just to start from a clean state
@@ -619,25 +625,25 @@ void testFuelSchedulerBug299(void) {
 		scheduling_s *ev = schedulingQueue.getForUnitText(0);
 
 		assertREqualsM("Call@0", (void*)ev->callback, (void*)seTurnPinHigh);
-		assertEqualsM("ev 0", start + MS2US(24), ev->momentX);
+		assertEqualsM("ev 0", start + MS2US(27), ev->momentX);
 		assertEqualsLM("in 0", (long)&enginePins.injectors[3], (long)ev->param);
 	}
 	{
 		scheduling_s *ev = schedulingQueue.getForUnitText(1);
 		assertREqualsM("Call@1", (void*)ev->callback, (void*)seTurnPinLow);
-		assertEqualsM("ev 1", start + MS2US(27), ev->momentX);
+		assertEqualsM("ev 1", start + MS2US(30), ev->momentX);
 		assertEqualsLM("in 1", (long)&enginePins.injectors[3], (long)ev->param);
 	}
 	{
 		scheduling_s *ev = schedulingQueue.getForUnitText(2);
 		assertREqualsM("Call@2", (void*)ev->callback, (void*)seTurnPinHigh);
-		assertEqualsM("ev 2", start + MS2US(34), ev->momentX);
+		assertEqualsM("ev 2", start + MS2US(37), ev->momentX);
 		assertEqualsLM("in 2", (long)&enginePins.injectors[1], (long)ev->param);
 	}
 	{
 		scheduling_s *ev = schedulingQueue.getForUnitText(3);
 		assertREqualsM("Call@3", (void*)ev->callback, (void*)seTurnPinLow);
-		assertEqualsM("ev 3", start + MS2US(37), ev->momentX);
+		assertEqualsM("ev 3", start + MS2US(40), ev->momentX);
 		assertEqualsLM("in 3", (long)&enginePins.injectors[1], (long)ev->param);
 	}