✅ Quickly diagnose "no start" and engine misses conditions in the electrical fuel injection and spark plug circuits. ✅ Analyze rough running engines. ✅ Includes: Cat. No. 23970, In-Line Spark Checker Kit for Recessed plugs (A must for testing newer vehicles with recessed spark plugs plus conventional and coil-on plug ignition systems); 8 Noid Lights (for checking GM PFI, FORD TBI, GEO TBI, BOSCH PFI, GM TBI, GM SCPI, BOSCH 2 and GM Multec 2); and 2 IAC Test Lights (for straight and 90° applications).