some pictures and slides courtesy of jerry delena mcvths thanks jerry l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Some pictures and slides courtesy of Jerry Delena MCVTHS Thanks Jerry PowerPoint Presentation
Download Presentation
Some pictures and slides courtesy of Jerry Delena MCVTHS Thanks Jerry

Loading in 2 Seconds...

play fullscreen
1 / 59

Some pictures and slides courtesy of Jerry Delena MCVTHS Thanks Jerry - PowerPoint PPT Presentation


  • 174 Views
  • Uploaded on

Some pictures and slides courtesy of Jerry Delena MCVTHS Thanks Jerry. Will need Pinto and scope. Chrome. Scope connection. Red (trigger). #1 spark plug. Blue. Black to common. Not an acceptable use of a scope . Scope Screen. V O L T A G E. T I M E. Scope Screen. Voltage is

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Some pictures and slides courtesy of Jerry Delena MCVTHS Thanks Jerry' - tyra


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
scope connection

Chrome

Scope connection

Red (trigger)

#1 spark

plug

Blue

Black

to common

scope screen5

V

O

L

T

A

G

E

T I M E

Scope Screen

Voltage is

usually in

thousands

of volts (KV)

Time can be

in degrees of

rotation or in

milliseconds (mS)

All vertical lines

represent a

change in

voltage

All horizontal

Lines represent

a change in

time

scope screen6
Scope Screen

0 to 5000

volts over

no time

scope screen7
Scope Screen

0 to 5000

volts over

little time

scope screen8
Scope Screen

0 to 5000

volts over

more time

scope screen9
Scope Screen

5000 to 6000

volts over

long time

scope screen10
Scope Screen

6000 volts

steady over

length of

time screen

is set for

scope screen11
Scope Screen

Steady 6000

to 0 volts

over no time

secondary patterns
Secondary Patterns
  • Display actual voltage needed to fire each spark plug (firing voltage)
  • Duration of each spark (spark line)
  • Coil condition (oscillations)
  • Displayed two different ways
    • Display or Parade
    • Raster
parade or display
Parade or Display

Parade pattern

Time on screen represents

Two revolutions of

Crankshaft or (7200)

raster
Raster

Raster pattern

Time on screen represents

maximum Dwell time

8 cyl = 450

6 cyl = 600

4 cyl = 900

secondary pattern

Points open

Here or

Transistor

Turns off

Secondary pattern

Firing voltage

5-14KV

Maximum of

3 KV difference

between cylinders

0 volts

Firing Section

Dwell Section

Intermediate

Section

secondary pattern16

Spark starts

here

Spark stops

here

Secondary pattern

Firing voltage

5-14KV

0 volts

Firing Section

Dwell Section

Intermediate

Section

secondary pattern17

Coil saturation

Magnetic field

starts building

in coil primary

Secondary pattern

Firing voltage

Spark line

Coil oscillations

(coil condenser with points)

Points close or

transistor turns

on here

5-14KV

.5-2.5KV

0 volts

Firing Section

Dwell Section

Intermediate

Section

secondary pattern18

Points open or

transistor turns

off here starting

the process over

for the next cyl.

Secondary pattern

Firing voltage

Spark line

Coil oscillations

(coil condenser with points)

Points close or

transistor turns

on here

5-14KV

.5-2.5KV

0 volts

Firing Section

Dwell Section

Intermediate

Section

slide19

Firing Order

1-8-4-3-6-5-7-2

Starts from where you hook

up the red trigger pick-up

M

U

S

T

K

N

O

W

Raster

Parade

Same pattern

displayed differently

firing order
FIRING ORDER
  • Most older scopes shift # 1 cylinder to the far right
  • Some scopes you can shift it back
slide24

Look for firing voltage

to be within 3 KV of

each other

Look for spark lines to

be a reasonable amount

(500 – 2500 V)

Firing section (parade)

Look for firing voltage

to be a reasonable

amount (5 – 14 KV)

Look for straight up

firing voltage lines

factors that affect firing voltage
Factors that affect firing voltage

The voltage

induced into

secondary

winding only

rises enough

to push

current across

the air gaps

Rotor

air

Gap

.060 - .100”

Spark

Plug

Gap

.030 - .080”

factors that affect firing voltage26
Factors that affect firing voltage

Once the gaps are

ionized, (current flowing)

it only takes a couple

KV to keep current

flowing

factors that affect firing voltage27
Factors that affect firing voltage

X

X

I was taught that this

was a series circuit

and all the resistance

added up to determine

the firing voltage

X

X

X

X

X

X

X

X

factors that affect firing voltage28
Factors that affect firing voltage

New theory is called “The Dominating Gap Theory”

Remember

spark plug

is under

compression

when it

fires

Rotor

air

Gap

.060 - .100”

Spark

Plug

Gap

.030 - .080”

factors that affect firing voltage29
Factors that affect firing voltage

Cylinder pressure

A/F mixture

Turbulence

Any gap or break

in circuit that acts

greater than plug

Dominating gap theory

“Greatest gap theory”

firing section raster

Can’t see firing voltage very

well displayed this way!

Firing section (raster)

Look for length and

angle of spark lines

Length should be

between .8 – 2.2 mS

secondary pattern firing section32
Secondary patternFiring section

What it shows wrong with ignition system?

Normal

Grounded plug wire

Narrow plug gap

10 KV

3 KV

Compare

1.5 mS

2 KV

2.5 mS

.5 KV

What is wrong about the pattern?

Too low firing voltage

Too long spark line

spark plug under load test
Spark Plug Under Load Test

Snap throttle

Cylinder pressure goes up

Mixture goes lean

KV should all go up about

the same

On deceleration

Cylinder pressure goes down

Mixture goes rich

KV should all go down about

the same

secondary pattern firing section34
Secondary patternFiring section

What it shows wrong with ignition system?

Normal

Wide gap (plug, plug wire

coil wire/rotor if on all cylinders)

10 KV

Compare

1.5 mS

2 KV

18 KV

What is wrong about the pattern?

Too high firing voltage

Too high spark line voltage

Too short spark line

.7 mS

5 KV

snap throttle test
Snap throttle test

Has to be inside cylinder

If it does this on acceleration

think of the firing voltage line and spark line as a string
Think of the firing voltage line and spark line as a string
  • It you use more of it on the firing voltage line you will have less for the spark line
secondary pattern firing section37
Secondary patternFiring section

What it shows wrong with ignition system?

Turbulence (burnt valve, wild cam)

Next one down

12 KV

1.5 mS

What is wrong about the pattern?

2 KV

Spark line is too rough

secondary pattern firing section38

Downward spike should

be about ½ of firing KV

showing good coil insulation

Secondary patternFiring section

What it shows wrong with ignition system?

22 KV

Plug wire off (no spark)

Next one down

This is how we check for

Maximum coil output

What is wrong about the pattern?

Firing KV too high

No Spark line

-11 KV

secondary pattern firing section39
Secondary patternFiring section

What it shows wrong with ignition system?

Very wide plug gap

Wire part way off or broken

Next one down

20 KV

.3 mS

15 KV

What is wrong about the pattern?

Firing KV too high

Spark line is too high

Spark line too short

secondary pattern firing section40
Secondary patternFiring section

What it shows wrong with ignition system?

Points arcing when opening

Second one down

On the right

What is wrong about the pattern?

Firing line not straight up

secondary pattern firing section41
Secondary patternFiring section

What it shows wrong with ignition system?

Very narrow plug gap (fouled plug)

Wire jumping to common (snap test)

Next one down

3 KV

3.5 mS

.5 KV

What is wrong about the pattern?

Firing KV too low

Spark line too long

secondary pattern firing section42
Secondary patternFiring section

What it shows wrong with ignition system?

Lean mixture

Next one down

14 KV

.8 mS

2 KV

What is wrong about the pattern?

Spark line tapers up on end

secondary pattern firing section43
Secondary patternFiring section

What it shows wrong with ignition system?

Intermittent miss (plug or

Wire jumping to ground)

Last one

12 KV

.8 mS

2 KV

.5 KV

What is wrong about the pattern?

Spark line keeps changing length

And height

secondary pattern raster intermediate and dwell section47
Secondary patternRaster (intermediate and dwell section)

Normal raster pattern

1.5 mS

What is wrong about the pattern?

Point close line not straight down

Point opening line not straight up

What about the ignition system that

would cause this kind of problem

Points arcing when closing and opening

secondary pattern raster intermediate and dwell section48
Secondary patternRaster (intermediate and dwell section)

Next one down

What is wrong about the pattern?

Not enough coil oscillations

No oscillations when field saturates

What about the ignition system that

would cause this kind of problem

Bad coil

secondary pattern raster intermediate and dwell section50
Secondary patternRaster (intermediate and dwell section)

Next one down

What is wrong about the pattern?

Dwell section is not flat after saturation

What about the ignition system that

would cause this kind of problem

Loose primary connection

secondary pattern raster intermediate and dwell section51
Secondary patternRaster (intermediate and dwell section)

Next one down

What is wrong about the pattern?

Dwell section is not flat after saturation

What about the ignition system that

would cause this kind of problem

Diodes bad in alternator (AC voltage)

secondary pattern raster intermediate and dwell section52
Secondary patternRaster (intermediate and dwell section)

Last one

Superimposed pattern

All patterns stacked on top of each other

Good for comparing each other

secondary pattern raster intermediate and dwell section53
Secondary patternRaster (intermediate and dwell section)

Last one

30 variation

Or less

60 variation or less on

point closing or transistor

turning on

Point opening

or transistor

shutting off

is critical

what do you think
What do you think?

9.5

9.5

11

11

5.5

5.5

5.5

5.5

Assuming

we are starting

at 0 volts

slide57

Secondary pattern

180 to 200 volts

Battery voltage

Primary pattern

as read at “-” of

coil

-80 to -100 volts

rotor gap test
Rotor gap test

Scope set on parade

Remove one plug wire and

Install a grounded wire

Read firing KV for that cylinder

Should be less than 5KV

We have eliminated the plug

and plug wire