Injector Circuit

For this assignment we were given this diagram 

according Motorola Datasheet current gain on BC547 transistors is 110 to 800

Voltage = 12V

choosing proper resistors for LEDs:

ILED = 30mA

VLED = 1.8V

RLED = (VSupply - VLED) / ILED

RLED = (12-1.8)/0.03= 340 Ohms

So I would use two 330R resistors for R14 and R15

β=Ic/Ib

Ib=Ic/β

Ib=30/110=0.27mA

R=(5V-0.7V)/0.00023A=18695.65 Ohms

so I choose to use 15K resistors for R13 and R16

Parts List:

BC547 transistor x 2

Green LED x 1

Red LED x 1

330R resistor x 2

15K resistor x 2

PC board 

Lochmaster Diagram

Video

O2 sensor Tester

Calculations:

R5
V=12V-9V=3V
I=5.6mA

V=IR
R=V/R
R5=3/0.0056=535.7 Ohms

====================================================================

Vtotal = 9V
V(R7)=0.23V
V(R8)=0.63V-0.23V=0.4V
V(R6)=9V - 0.63V = 8.37V
R6= 10 000 Ohms

I=V/R
I = 8.37/10 000 = 0.000837A =0.837mA

R8 = 0.4/0.000837= 477.9 Ohms
R7 = 0.23/0.000837 = 274.8 Ohms

====================================================================

R = (Vs-Vled)/Iled

R2 = (12-1.8)/0.0095= 1073.7 Ohms
R3/4 = (12-1.8-0.7)/0.0095 = 1000


=====================================================================



Part list:

3 x Diodes 1N4001
3 x Resistors 1K
1 x Zener Diode 9V1
1 x 3mm Green LED
1 x 3mm Yellow LED
1 x 3mm Red LED
2 x Capacitors 0.1uF
1 x Resistor 10K
1 x Resistor 270R
1 x Resistor 470R
1 x Resistor 540R
1 x IC LM324AM


====================================================================



Lochmaster Diagram:


top side:

Bottom Side:

Video:

Checking Alternators

On car check


Checking alternator on 1991 Toyota MR2. Make sure that the vehicle is in neutral (or park) and hand brake is applied firmly.
Check list:

1. Does Charge light work?  Yes
2. Visual condition of the connectors. OK
3. Alternator mounting. OK
4. Fuses and fusible links. OK
5. Condition of the drive belt (tension, cracks or rips). OK

Tools required: Hight rate discharge tester, multimeter, clamp amp meter.

No load test.
Battery OCV (Open Circuit Voltage) - 12.67V
for this test all doors need to be closed, all lights switched off and ignition key is out. Alternatively, Battery negative terminal can be disconnected. Using digital multimeter measure voltage of the battery.

Specified Regulator voltage - 14.9V 
voltage is found in service manual for the car. acceptable voltage is 13.5V to 15V


Regulator Voltage Reading - 14.89V
start the car. measure the voltage at the battery while engine is running.

No load Current output - 15A @14.7V
Clamp Amp Meter required for this test. place clamp over negative/positive battery terminal. readings for carburettered car should be 5A to 12A and for fuel injected - 10A to 18A.


Current output under the load - 80A@13.4V
High Rate Discharge Tester is required for this task. Dial 50 Amps on the Tester, start the engine and connect the tester terminals to the battery. Rev the car up to 2000 RPM and turn the tester ON for no more than 20seconds. Take the readings from Load Tester.


The Alternator has Passed all tests and it is fully functional.


OFF Car Check


Visual inspection: check the alternator for any Damage to back cover, bearings, terminals...

Disassembly:

<!--[if !supportLists]-->1.        <!--[endif]-->Unscrew the nut on “B+” terminal and insulator.

<!--[if !supportLists]-->2.        <!--[endif]-->Remove three nuts holding the back cover and take it off

3.        Remove the brush holder and voltage regulator.

4.        Remove the four screws that hold the rectifier, remove the rectifier.

5.        Remove the four screws that hold the voltage regulator, remove the regulator.

5 Volt Regulator/rectifier

For this assignment we have been given out the following parts:
4 x Diodes 1N4001
2 x Capacitors 100 uF
1 x Red LED
1 x Green LED
1 x Voltage regulator TS7805
2 x 1K Resistors
1 x Circuit board
different colored wires



The circuit diagram (updated)

Lochmaster printout

AC voltage coming from Neutral (N) and Phase (P) connectors is getting rectified by four diodes to DC voltage. then Red LED lights up indicating that rectifier works correctly. Green LED after voltage regulator indicates that voltage is 5V after regulator.


testing:
supplying 12V DC after rectifier, both LED lights should light up

Supplying AC Voltage to the rectifier

Red wire reads 17.35V DC

the white wire reads 4.9V DC

Mazda B5 Engine Head/Block

Removing Cylinder Head from Mazda B5 Engine

     1.  Disconnect all cables and hoses that connected to cylinder head

     2.       Remove exhaust and intake manifolds

     3.       Take rocker cover off 

     4.       Remove timing belt cover

     5.       Mark direction and position of the belt at #1 cylinder TDC

6.       

    6. Carefully pull the belt off the cam sprockets

    7.   Holding cam with size 24 spanner, remove the cam shaft sprocket screw on each cam (note I-for intake and E- for exhaust markings on sprockets)

    8.  Take the metal timing belt protecting cover off   

    9.   Loosen the head bolts in order:

             Intake Side      

              1 7  9  6 4

              3 5 10 8 2

            Exhaust Side

  

     

      10.   Carefully lift the Engine Head, do not use screw driver or similar, because it is really easy to damage the machined surface of Head and Block.

Disassembling Engine Head

1.      

    1.  Loosen the cam shaft holding bolts

    2.  Keep cam shaft holders in order (note, arrow imprinted on cam holders indicates towards the crankshaft pulley, Letter “I” – stands for Intake side and “E”- stands for Exhaust side, numbers on each holder represents the position of the holder starting from “1”- from crank pulley)

    3.  Mark each valve’s position (eg. E1, E2….E8) (Tip: cardboard box can be used to keep valves in order. Simply pop the valve through the cardboard and write the position of the valve on the box)

      4.  Using correct size valve spring compressor remove the valves (Tip: magnet or magnetic screwdriver can be used to remove the valve keepers)

5.       Note that some of the valve springs have top and bottom sides

Inspecting Cylinder Head

1.       Visual check of all components for any damage

2.       With metal ruler and filler gauge check the warp across, along and diagonal of the head surface. In my case it seems like head has been machined and it is 0mm warp in every direction.

3.       Make sure that valve guides are not damaged, visually check every valve guide. They all in OK condition (no cracks, no rust, no carbon built ups)

Valve Stem Measurement

Three measurements need to be taken per valve. Top (A), Middle (B) and Bottom (C) of the stem.

	Cylinder 1		Cylinder 2		Cylinder 3		Cylinder 4
A on Valve 1	5.975mm	5.98mm	5.98mm	5.98mm	5.98mm	5.975mm	5.98mm	5.975mm
A on Valve 2	5.975mm	5.975mm	5.975mm	5.975mm	5.98mm	5.97mm	5.975mm	5.97mm
B on Valve 1	5.975mm	5.975mm	5.975mm	5.975mm	5.98mm	5.97mm	5.98mm	5.975mm
B on Valve 2	5.975mm	5.975mm	5.975mm	5.97mm	5.975mm	5.97mm	5.975mm	5.975mm
C on Valve 1	5.975mm	5.97mm	5.975mm	5.97mm	5.975mm	5.97mm	5.975mm	5.975mm
C on Valve 2	5.975mm	5.97mm	5.975mm	5.975mm	5.975mm	5.975mm	5.975mm	5.97mm
	In	Ex	In	Ex	In	Ex	In	Ex
Average Reading 1	5.975mm	5.975mm	5.976mm	5.975mm	5.978mm	5.972mm	5.978mm	5.975mm
Average Reading 2	5.975mm	5.973mm	5.975mm	5.973mm	5.977mm	5.972mm	5.975mm	5.972mm

Unable to measure valve guides, therefore cannot calculate Valve Stem to Guide clearance. Specified clearance is 0.03mm – 0.04mm for Intake side, 0.04mm – 0.05mm for exhaust side.

Valves Condition

Examine all valves for any damage

Cylinder 1

Cylinder 2

Cylinder 3

Cylinder 4

Ex1

Ex2

In1

In2

Ex1

Ex2

In1

In2

Ex1

Ex2

In1

In2

Ex1

Ex2

In1

In2

Damage to the tip

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

Damage or wear in collet grooves

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

Pitting or erosion of valve stem

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

Marks on stem that have sharp edges

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

Signs of scuffing or seizure

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

Cracks or erosion in fillet area

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

Stretching of the stem

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

Straightness of the stem

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

Mechanical damage to the head, erosion or cupping

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

Valve Margin

1.5

1.2

1.0

1.0

1.6

1.5

0.8

0.8

1.2

1.2

0.9

0.9

1.2

1.5

0.5

0.5

Since minimum Valve margin is 1mm then 6 Valves need to be serviced/replaced.

Visually check the Valve seats for seat width, angle, thickness of remaining material and any sort of damage (cracks, erosion..)

Inspecting Valve Springs

Put a spring upright on flat surface and place a combination square next to it. Rotate the spring and measure the distance between a combination square and top of the spring with feeler gauge. It should not be more than 1/16 inch (1.59mm). The spring that is not square would cause uneven wear on Valve stem and Guide.

Cylinder #				Ok	Fail
1	In	1mm	1mm	V
	Ex	1mm	1mm	V
2	In	1mm	1mm	V
	Ex	0mm	1mm	V
3	In	0mm	1mm	V
	Ex	1mm	1mm	V
4	In	1mm	1mm	V
	Ex	1mm	1mm	V

Check the free length of the Valve Spring

Note all springs must be within 1.5mm of each other

Cylinder #				Ok	Fail
1	In	47mm	47mm	V
	Ex	47mm	47mm	V
2	In	47mm	47mm	V
	Ex	47mm	47mm	V
3	In	47mm	47mm	V
	Ex	47mm	47mm	V
4	In	47mm	47mm	V
	Ex	47mm	47mm	V

Valve Spring Tension

Valve Spring Pleasure tester is required. Place the spring in to the tester and compress the spring to 40mm and record the result. All springs should be within 5kg range.

Cylinder #				Ok	Fail
1	In	16.7kg	16.6kg	V
	Ex	17.2kg	17.5kg	V
2	In	17.1kg	17kg	V
	Ex	17.6kg	17.2kg	V
3	In	16.5kg	16.9kg	V
	Ex	17.1kg	16.9kg	V
4	In	17.5kg	17.1kg	V
	Ex	17kg	17.2kg	V

Inspecting camshaft for wear and general condition

Using micrometer measure camshaft lobes

Tightening sequence is....

intake side
8 6 2 4 10
9 3 1 5 7
exhaust side