WS3B Oscilloscope Pattren Capture (Two Channels)

WS3B Lab Scope
Make & Model: Toyota 4A - FE engine
Signal Name: MAp analuge Signal aginst Injectors.
Volt/division/ range: A: 0.5V channel B : 20V
Time/division/range: 10 ms

This test was done with engine idling. A channel is hooked up to MAP and has 0.5V divisions. B channel is hooked up to an injector and has 20V divisions. Point A on the photo is the voltage signal from the from the (MAP) manifold absolute pressure sensor. It is approx. 0.5V wile idling. Point B is the injector turn on this is about 20ms the voltage is 0v because the injectors are earth triggered. Point C is the injector opening time because this ggronding. Point D high voltage spike,by is generated by the collopsing magnitic filed within injectorwinding shows the injector closed it has just nearlrly 50V, and point C back to EMF.

Explain in detail how these two components relate to each other.

The MAP sensor measures intake manifold pressure and this is directly related to engine load. The voltage signal sent from the MAP sensor is used by the ECU which interprets any change in voltage as a change in pressure. This helps the ECU calculate how long to open the injectors in varying engine loads.

Signal Name: RPM (analuge voltage against Injector.
Volt/division/range; A RPm, 2V, channel B injector 20V
Time/division/range: 10 ms

Channal B arrow D the injector turrned on, arrow F gornding in this point injector open spray time because injector is negative trigger, arrow C high voltage injector turn closed , arrow C back to EMF. ChanalA RPM waveform peak to peak voltage arrow E to D

RPM sensor and injector. Common thing in both of them is that they start to open and ignite spark plug faster with increase of RPM's, so frequency increases. If injector not working properly or fuel pressure is low or high, it will make engine misfire or have a flat spots in acceleration. Same as spark plugs ignites at the wrong time they can cause detonation in the engine and damage it.

RPM sensor or distributor magnitec pickup and injuctor , if we increase rpm we can see that friquncy for rpm sensor and injector increases that because engine uning faster injecter need fuel spray faster and also fast sparking.

Signal Name: Oxyg;en Sensor against Injectors.

Volt/division/range : channal A O2 sensor 1V, channal B fuel injector 20V.

Time/division/range; 10 ms

Channel A is the oxygen sensor point A is approx 0.1v this means air/fuel mix is lean and point B 0.5v meaning the air/fuel mix is richer.The O2 sensor waveform is straight because i had set the voltage range per divsion 1 volt taht shuold be high for O2 sensor . If i set low voltage and low time than i could not catch good pattren for the injector. Channel B is the injector  you can still see where the injector is opening at point C injector ON time means turn on, and bottom arrow  when the voltage drops to 0v because they are earth triggered. Point D is colopsing voltage because the high voltage is generated by the colopsing magnitec fild.

Explain in detail how these two components relate to each other.

When the engine is warm and go's into closed loop operation the oxygen sensor will start cycling between slightly rich air/fuel mixture and slightly lean air/fuel mixture. This voltage signal from the oxygen sensor in part will be used to calculate how long the fuel injectors should be open

Some more explanition:

The O2 sensor is very important this control of exhaust emmission in catalytic equipped vehicle.

The sensor have varying electrical conniction it is creat to oxygen in the exhaust system, will produce a samal voltage depend an Air/fuel mixture set at time.

The voltage rang seen in the most cases vary between 0.2V to 0.9V at 0.2V indicated a lean mexture , and 0.8v indicated a rich mixture.

A vihecle equpped with lambda sensor said to have close loop , this means that after the fuel has burnet during the cumbustion prosces, the sensor will analyses the emmission and adjust the engine fullrity accordaaingle.

Signal Name: Ignation Primary against Fuel injectors:

Voltage/divsion/range: cahanal A, Ignation 20V, channal B injector 20V

Time/division/range; 10 ms

Channel B is the injector signal, at point E the injector opens for 6ms then at point F the injector closes and you can see the back EMF of approx 55v. Channel A is ignition primary you can see the coil is grounded about 10ms after the injectors opened at point E Point A is the ignaatio ON time, at point B is the firng voltage, atpointC is dweel time wich coil is grounding and burning voltrage wich i dont mark it, it after firing voltage.  

Explain in detail how these two components relate to each other.

Because the primary coil is the first part of stepping up the battery voltage for the spark needed for ignition the injector and the coil need to have very precise timing.