diff --git a/core/pipeline.go b/core/pipeline.go
index c677c5f..524a0f9 100644
--- a/core/pipeline.go
+++ b/core/pipeline.go
@@ -9,8 +9,6 @@ import (
 	"time"
 )
 
-// TODO: adapt HNR-INS data to continue orientation stream
-
 type Processor interface {
 	Process(data *Sensordata) error
 }
@@ -125,11 +123,16 @@ func (p *pipeline) refreshDelay() error {
 	p.agr.serialMutex.Unlock()
 	p.agr.tcpMutex.Unlock()
 	if tcpTime.UnixNano() == 0 || serTime.UnixNano() == 0 {
-		return errors.New("no sync possible. no data to compare")
+		return errors.New("no sync possible. check if both collectors running. otherwise check GPS fix")
+	}
+	currentDelay := tcpTime.Sub(serTime).Milliseconds()
+	if currentDelay > 5000 || currentDelay < -5000 {
+		p.syn.tcpSerialDelayMs = 0
+		return errors.New("skipping synchronisation! time not properly configured or facing network problems.")
 	}
 	log.Println("TCP", tcpTime.String())
 	log.Println("SER", serTime.String())
-	log.Println("Difference", tcpTime.Sub(serTime).Milliseconds())
+	log.Println("Difference", tcpTime.Sub(serTime).Milliseconds(), "ms")
 	delay := tcpTime.Sub(serTime).Milliseconds()
 	p.syn.tcpSerialDelayMs += delay
 	return nil