diff --git a/beacon/light/api/api_server.go b/beacon/light/api/api_server.go
index a925bd3536..9b4ead07f2 100755
--- a/beacon/light/api/api_server.go
+++ b/beacon/light/api/api_server.go
@@ -40,8 +40,10 @@ func NewApiServer(api *BeaconLightApi) *ApiServer {
 func (s *ApiServer) Subscribe(eventCallback func(event request.Event)) {
 	s.eventCallback = eventCallback
 	s.unsubscribe = s.api.StartHeadListener(func(slot uint64, blockRoot common.Hash) {
+		log.Debug("New head received", "slot", slot, "blockRoot", blockRoot)
 		eventCallback(request.Event{Type: sync.EvNewHead, Data: types.HeadInfo{Slot: slot, BlockRoot: blockRoot}})
 	}, func(head types.SignedHeader) {
+		log.Debug("New signed head received", "slot", head.Header.Slot, "blockRoot", head.Header.Hash(), "signerCount", head.Signature.SignerCount())
 		eventCallback(request.Event{Type: sync.EvNewSignedHead, Data: head})
 	}, func(err error) {
 		log.Warn("Head event stream error", "err", err)
diff --git a/beacon/light/request/request.go b/beacon/light/request/request.go
index 15038ff20f..2a04b59212 100644
--- a/beacon/light/request/request.go
+++ b/beacon/light/request/request.go
@@ -16,6 +16,12 @@
 
 package request
 
+import (
+	"math"
+
+	"github.com/ethereum/go-ethereum/log"
+)
+
 type (
 	Request     any
 	Response    any
@@ -40,14 +46,20 @@ func (p *RequestTracker) TryRequest(requestFn func(server Server) (Request, floa
 		bestServer                            Server
 		bestRequest                           Request
 	)
-	maxServerPriority, maxRequestPriority = -1000, -1000
+	maxServerPriority, maxRequestPriority = -math.MaxFloat32, -math.MaxFloat32
+	serverCount := len(p.servers)
+	var removed, candidates int
 	for server, _ := range p.servers {
 		canRequest, serverPriority := server.CanRequestNow()
 		if !canRequest {
 			delete(p.servers, server)
+			removed++
 			continue
 		}
 		request, requestPriority := requestFn(server)
+		if request != nil {
+			candidates++
+		}
 		if request == nil || requestPriority < maxRequestPriority ||
 			(requestPriority == maxRequestPriority && serverPriority <= maxServerPriority) {
 			continue
@@ -55,6 +67,7 @@ func (p *RequestTracker) TryRequest(requestFn func(server Server) (Request, floa
 		maxServerPriority, maxRequestPriority = serverPriority, requestPriority
 		bestServer, bestRequest = server, request
 	}
+	log.Debug("Request attempt", "serverCount", serverCount, "removedServers", removed, "requestCandidates", candidates)
 	if bestServer == nil {
 		return ServerAndId{}, nil
 	}
diff --git a/beacon/light/request/scheduler.go b/beacon/light/request/scheduler.go
index 00c5aabaa7..87264235ed 100644
--- a/beacon/light/request/scheduler.go
+++ b/beacon/light/request/scheduler.go
@@ -48,6 +48,7 @@ type Scheduler struct {
 	lock         sync.Mutex
 	clock        mclock.Clock
 	modules      []Module // first has highest priority
+	names        map[Module]string
 	trackers     map[Module]*RequestTracker
 	servers      map[Server]struct{}
 	pending      map[ServerAndId]pendingRequest
@@ -61,7 +62,7 @@ type Scheduler struct {
 
 type ServerEvent struct {
 	Server Server
-	Type   int
+	Type   string
 	Data   any
 }
 
@@ -83,6 +84,7 @@ func NewScheduler(clock mclock.Clock) *Scheduler {
 	s := &Scheduler{
 		clock:    clock,
 		servers:  make(map[Server]struct{}),
+		names:    make(map[Module]string),
 		trackers: make(map[Module]*RequestTracker),
 		pending:  make(map[ServerAndId]pendingRequest),
 		stopCh:   make(chan chan struct{}),
@@ -98,7 +100,7 @@ func NewScheduler(clock mclock.Clock) *Scheduler {
 // RegisterModule registers a module. Should be called before starting the scheduler.
 // In each processing round the order of module processing depends on the order of
 // registration.
-func (s *Scheduler) RegisterModule(m Module) {
+func (s *Scheduler) RegisterModule(m Module, name string) {
 	s.lock.Lock()
 	defer s.lock.Unlock()
 
@@ -107,6 +109,7 @@ func (s *Scheduler) RegisterModule(m Module) {
 		scheduler: s,
 		module:    m,
 	}
+	s.names[m] = name
 }
 
 // RegisterServer registers a new server.
@@ -191,6 +194,12 @@ func (s *Scheduler) processModules() {
 	s.serverEvents = nil
 	s.lock.Unlock()
 
+	eventTypes := make([]string, len(serverEvents))
+	for i, ev := range serverEvents {
+		eventTypes[i] = ev.Type
+	}
+	log.Debug("Processing modules", "servers", len(servers), "server events", eventTypes)
+
 	for _, module := range s.modules {
 		s.lock.Lock()
 		tracker := s.trackers[module]
@@ -198,6 +207,19 @@ func (s *Scheduler) processModules() {
 		requestEvents := tracker.requestEvents
 		tracker.requestEvents = nil
 		s.lock.Unlock()
+
+		var respCount, failCount, timeoutCount int
+		for _, ev := range requestEvents {
+			if ev.Response != nil {
+				respCount++
+			} else if ev.Finalized {
+				failCount++
+			} else {
+				timeoutCount++
+			}
+		}
+		log.Debug("Processing module", "name", s.names[module], "responses", respCount, "fails", failCount, "timeouts", timeoutCount)
+
 		if module.Process(tracker, requestEvents, serverEvents) {
 			s.Trigger()
 		}
diff --git a/beacon/light/request/server.go b/beacon/light/request/server.go
index 359a095554..8d13bfaf44 100644
--- a/beacon/light/request/server.go
+++ b/beacon/light/request/server.go
@@ -26,16 +26,15 @@ import (
 	"github.com/ethereum/go-ethereum/log"
 )
 
-const (
+var (
 	// request events
-	EvResponse = iota // data: IdAndResponse; sent by RequestServer
-	EvFail            // data: ID; sent by RequestServer
-	EvTimeout         // data: ID; sent by serverWithTimeout
+	EvResponse = "response" // data: IdAndResponse; sent by RequestServer
+	EvFail     = "fail"     // data: ID; sent by RequestServer
+	EvTimeout  = "timeout"  // data: ID; sent by serverWithTimeout
 	// server events
-	EvRegistered      // data: nil; sent by Scheduler
-	EvUnregistered    // data: nil; sent by Scheduler
-	EvCanRequestAgain // data: nil; sent by serverWithLimits
-	EvAppSpecific     // application specific events (sent by RequestServer) start at this index
+	EvRegistered      = "registered"      // data: nil; sent by Scheduler
+	EvUnregistered    = "unregistered"    // data: nil; sent by Scheduler
+	EvCanRequestAgain = "canRequestAgain" // data: nil; sent by serverWithLimits
 )
 
 const (
@@ -79,7 +78,7 @@ func NewServer(rs RequestServer, clock mclock.Clock) Server {
 type serverSet map[Server]struct{}
 
 type Event struct {
-	Type int
+	Type string
 	Data any
 }
 
diff --git a/beacon/light/sync/types.go b/beacon/light/sync/types.go
index 5b2df1359a..e3c6ea76cd 100644
--- a/beacon/light/sync/types.go
+++ b/beacon/light/sync/types.go
@@ -17,14 +17,13 @@
 package sync
 
 import (
-	"github.com/ethereum/go-ethereum/beacon/light/request"
 	"github.com/ethereum/go-ethereum/beacon/types"
 	"github.com/ethereum/go-ethereum/common"
 )
 
 const (
-	EvNewHead = iota + request.EvAppSpecific
-	EvNewSignedHead
+	EvNewHead       = "newHead"
+	EvNewSignedHead = "newSignedHead"
 )
 
 type (
diff --git a/cmd/blsync/main.go b/cmd/blsync/main.go
index 555a4317b2..5bf0aa13bb 100644
--- a/cmd/blsync/main.go
+++ b/cmd/blsync/main.go
@@ -19,6 +19,7 @@ package main
 import (
 	"context"
 	"fmt"
+	"io"
 	"os"
 	"strings"
 	"time"
@@ -34,7 +35,10 @@ import (
 	ctypes "github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/ethdb/memorydb"
 	"github.com/ethereum/go-ethereum/internal/flags"
+	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/rpc"
+	"github.com/mattn/go-colorable"
+	"github.com/mattn/go-isatty"
 	"github.com/urfave/cli/v2"
 )
 
@@ -83,6 +87,14 @@ func main() {
 }
 
 func blsync(ctx *cli.Context) error {
+	usecolor := (isatty.IsTerminal(os.Stderr.Fd()) || isatty.IsCygwinTerminal(os.Stderr.Fd())) && os.Getenv("TERM") != "dumb"
+	output := io.Writer(os.Stderr)
+	if usecolor {
+		output = colorable.NewColorable(os.Stderr)
+	}
+	verbosity := log.FromLegacyLevel(ctx.Int(verbosityFlag.Name))
+	log.SetDefault(log.NewLogger(log.NewTerminalHandlerWithLevel(output, verbosity, usecolor)))
+
 	if !ctx.IsSet(utils.BeaconApiFlag.Name) {
 		utils.Fatalf("Beacon node light client API URL not specified")
 	}
@@ -119,11 +131,11 @@ func blsync(ctx *cli.Context) error {
 		blockSync: beaconBlockSync,
 	}
 
-	scheduler.RegisterModule(checkpointInit)
-	scheduler.RegisterModule(forwardSync)
-	scheduler.RegisterModule(headSync)
-	scheduler.RegisterModule(beaconBlockSync)
-	scheduler.RegisterModule(engineApiUpdater)
+	scheduler.RegisterModule(checkpointInit, "checkpointInit")
+	scheduler.RegisterModule(forwardSync, "forwardSync")
+	scheduler.RegisterModule(headSync, "headSync")
+	scheduler.RegisterModule(beaconBlockSync, "beaconBlockSync")
+	scheduler.RegisterModule(engineApiUpdater, "engineApiUpdater")
 	// start
 	scheduler.Start()
 	// register server(s)