# Waveform libraries

Typical waveforms of sensor signals as well as engine management.

| Vacuum waveform diagnostics. The vacuum waveform in the intake manifold while cranking an engine with 200 000 Km.

| Vacuum waveform diagnostics. The cam-shaft is installed one tooth off from specification. The intake valve is opening too early. The vacuum in the intake manifold increase slowly because the intake valve has opened early but falls sharply as the piston still moves downwards on the intake stroke with the intake valve already closed.

| Vacuum waveform diagnostics. The vacuum waveform is uneven possible causes include: valves not seating, valves improperly adjusted, hydraulic lash adjusters not working properly, or loss of compression.

| Compression pressure waveform. The signal is obtained using a pressure sensor installed in place of the spark plug in one cylinder. The engine is at idle.

| Oxygen (Lambda) sensor waveform. Waveform from a good sensor showing the oxygen content in the exhaust. The engine is at idle.

| Waveform from a MAF (Mass Air Flow) sensor. Snap throttle.

| Waveform from a TP (Throttle Position) sensor. Ignition on, engine off. The throttle was opened slowly and evenly.

| Waveform from a bad TP-sensor. There is a glitch in the waveform.

| Fuel injector waveform. Snap throttle.

| Primary ignition waveform.

| Secondary ignition waveform. The waveform was obtained using the high voltage probe from the USB Autoscope II kit.

| Shorted ignition coil. The problem is easily seen as a lack of oscillations in the beginning of the intermediate section (just after the spark is extinguished).

| Waveform from a CKP (Crank Shaft Position) sensor. The engine is at idle.

| Waveform from a CKP. The reluctor is deformed.