GTC505m Engine Ignition Analyzer

Finding dead or malfunctioning coils and plugs can be hard work. The GTC505 makes ignition troubleshooting quick, easy, and painless. It’ll help you, and the people depending on you, get moving again!

The GTC505 is the product of 20 years of work (by GTC) on ignition diagnostics. This tool will tell you exactly what’s going on with any spark ignition system as soon as you put its sensor by your coil (or spark plug wire). Swapping coils and other components in and out until you figure out what’s wrong is slow, tedious, and wasteful. The GTC505 will take the guesswork out, so you can be confident that the problem will be solved on your first try.

USD $379.50

Available on backorder

Quick Links


Who it’s For:

  • Marine outboard mechanics
  • Gasoline inboard mechanics
  • Small engine repair shops doing fault diagnostics
  • Motorcycle technicians doing diagnostics or aftermarket modification
  • Automotive technicians looking for a GTC505 with all the extras

What it Does:

Quickly and easily detects engine RPM and spark parameters. Useful for checking for ignition system faults and misfires, or for tuning and aftermarket modifications.

How it Works:

  1. Connect the appropriate sensor
  2. Turn the unit on
  3. Position the sensor near the ignition module or wire
  4. Check the engine RPM, spark peak voltage, burn time, and dwell angle/ramp time. The digital view gives you a quick look at the average, and the chart view will show you any misfires.

Warranty & Support:

Covered by our standard 1-year warranty, and supported for much longer. Replacement parts and accessories are generally available for 10+ years.






Analyzer Specifications


Measures Engine RPM
Measures Peak Spark Voltage
Measures Spark Burn Time 
Measures Dwell Angle  
Measures Ramp Time  


Pickup Specifications


 TA100 sensorTA500 sensorGTC505 SPW sensorGTC505 COP sensor
Capacitive Sensor
Inductive Sensor   
Works on Capacitive Discharge Systems 
Works on Distributor Systems 
Works on Magneto System 
Works on Coil-On-Plug Systems  


How-To Videos



How to Connect the Flex-Arm and Sensors to the GTC505 Engine Ignition Analyzer

How to Detect Misfires with the GTC505 Engine Ignition Analyzer


What is the difference between the GTC505, the GTC505m, and the GTC014?

The GTC505 is an engine ignition analyzer. The most basic kit it comes in: with a flexible probe, extension cable, cop sensor, spw sensor, USB micro cable and AC charger adapter, user’s manual, 1 year warranty, and hard padded carrying case.

The GTC505m is an upgraded version of the GTC505 kit – it comes with everything in the GTC505 kit, but with the GTC014 accessory, and a larger hard padded carrying case to accommodate the extra accessory.

The GTC014 can be purchased separately (here), or together with the analyzer in the GCT505m kit.

Engine Ignition Analyzer 
Flexible Probe 
Coil on plug (COP) active sensor 
Spark plug wire (SPW) shielded capacitive sensor 
Clip-on spark plug wire capacitive sensor 
Extension cable with BNC and sensor connector 
USB micro cable and AC charger adapter 
Protective rubber holster 
Hard padded case for carrying and storage 
User’s manual 
1 year parts and labor warranty 



  Download Brochure (English)

  Download Manual (English)

Kit Manifest

  • GTC505 engine ignition analyzer (core unit)
  • flex-arm
  • COP pickup
  • SPW pickup
  • Clip-on SPW pickup
  • 2m (extended) cable
  • USB-A to micro-B USB cable 0.9m (3′) long
  • AC to USB power adapter (charger)
  • hard-shell, padded storage and carrying case
  • user’s manual


Parts & Accessories

Proposition 65 Warning ⚠

This product can expose you to chemicals including Styrene, which is known to the State of California to cause cancer, and Bisphenol A (BPA), which is known to the State of California to cause birth defects or other reproductive harm. For more information go to: