Transcript Nemisys Operating Class

Nemisys Advanced Class
Fuel Trim
Idle Test Results
Rich
Ideal
Rich
Lean
Lean
2500 RPM Test Results
Possible Cause
Ideal
Vacuum Leak
Rich
Low Fuel Volume
Rich
Low Fuel Pressure
Ideal
Contaminated Crank Case
Lean
Leaking Injectors
IAC Counts High
• Spec 10 to 30
• High IAC counts
– LTFT over +10
– MAP normal .8 to 1.5
Idle
• Check ignition
• Dirty intake valves,
Injectors, or
Throttle plates
• Leaking EGR
• Check fuel pressure
and volume
• Spec 10 to 30
• IAC Counts High over 40
– LTFT over +10
– MAP sensor high or MAF
sensor low <5
• Sticking IAC
• Dirty intake valves,
Injector, or Throttle
plates
• Check fuel pressure and
volume
• Low Manifold pressure
or compression
problems
• IAC motor stuck open
Fuel Control Test
Clear Flood Equipped Vehicles
A) DataStream
• TPS
• Injector Pulse Width
B) KOEO
C) WOT
• TPS 4.3 To 4.7 Volts
• Injector Pulse Width 0.0
Scan Tool Fuel Control Test
(Easy to get HO2S)
• 1) Disconnect HO2S
• 2) Datastream
– HO2S
– Injector Pulse Width
• 3) Volt Meter At HO2S Signal Return Wire at O2 sensor
• 4) KOER, Engine At Operating Temperature, 1000 Rpm
• 5) Place One Finger On PCM HO2S Signal Return Wire to the PCM
• 6) Place Another Finger At Battery Positive
– Datastream HO2S - 1 Volt
– Datastream Injector Pulse Width - Will Drop
– Volt Meter HO2S - 0 Volt
• 7) Place Finger At Battery Negative
– Datastream HO2S - 0 Volt
– Datastream Injector Pulse Width - Will Rise
– Volt Meter HO2S - 1 Volt
O2 Sensor Propane Test
• Propane enrichment testing to check that the
O2 sensors are working properly
• Select, graph and zoom the O2 sensors
• Propane enrichment increases the O2 output
above .91 volts, preferred is closer to 1.0
volt.
• Keep adding propane until RPM decreases,
to get the maximum output
• Remove the propane to see how fast the
voltage decreases. It should decrease in a
straight line
Timing Advance Datastream Test
• Datastream review of Timing
Advance versus RPM
• The timing advance should follow
RPM, except when in Wide Open
Throttle, when timing advance
decrease slightly
Timing Advance Datastream Test
• Datastream review of Timing
Advance versus TPS
• TPS moves and Spark changes
good reaction and timing curve
Timing Advance Datastream Test
• Datastream review of Timing
Advance versus MAP
• The spark advance must follow the
MAP sensor load changes
MAF Test
• 1) KOER, Engine At Operating Temperature
• 2) Scan Tool Datastream
– MAF GPS
• (Frequency May Be Substituted For GPS)
• 3) Mark Points Of MAF GPS On Graph Paper
– 1000 Rpm
– 1250 Rpm
– 1500 Rpm
– 1750 Rpm
– 2000 Rpm
• 4) Connect Plot Points, Graph Line Should Rise
Smooth
Good MAF Graph
GPS
RPM
1000
1250
1500
1750
2000
Bad MAF Graph - Out of Calibration
GPS
RPM
1000
1250
1500
1750
2000
Bad MAF Graph - Air Leak
GPS
RPM
1000
1250
1500
1750
2000
MAF Test
• Select and graph RPM and
MAF
• Ford MAF sensor should reach
a output of above 3.5 volts with
a snap throttle
GM MAF TEST
• GM with a snap throttle should go
above the 5.4 kHz for a good
sensor output
• Check MAF sensing wires or clean
the wires, and check the duct work
for leaks after the MAF sensor
GM MAP Sensors
Vacuum
0”
3”
6”
9”
12”
15”
18”
21”
Voltage
4.5-4.7 V
4.0-4.2 V
3.5-3.7 V
3.0-3.2 V
2.5-2.7 V
2.1-2.3 V
1.5-1.7 V
.9-1.1 V
Scan Data
29-30”
26-27”
23-24”
20-21”
17-18”
14-15”
11-12”
8-9”
GM/Chrysler BARO Readings
Altitude
Baro Pressure
Voltage
0-1000’
29-30”
4.5-4.8 V
1000 to 2000’
28-29
4.3-4.5 V
2000 to 3000’
27-28”
4.1-4.3 V
3000 to 4000’
26-27”
3.9-4.1 V
4000 to 5000’
25-26”
3.8-4.0 V
Chrysler MAP
Vacuum
Voltage
Scan Data
0”
4.5-4.8 V
29-30”
3”
4.0-4.2 V
26-27”
6”
3.5-3.7 V
23-24”
9”
3.0-3.2 V
20-21”
12”
2.5-2.7 V
17-18”
15”
2.1-2.3 V
14-15”
18”
1.5-1.7 V
11-12”
21”
.9-1.10 V
8-9”
Ford MAP Sensors
Vacuum
0”
3”
6”
9”
12”
15”
18”
21”
Frequency in HZ
159 Hz
150 Hz
141 Hz
132 Hz
123 Hz
114 Hz
105 Hz
96 Hz
FORD BARO Readings
Altitude Vs. Frequency
0-1000’
29-30”
159-163 Hz
1000-2000’
28-29”
153-157 Hz
2000-3000’
27-28”
150-153 Hz
3000-4000’
26-27”
147-153 Hz
4000-5000’
25-26”
144-150 Hz
MAP Sensor Test
• 1) Scan Tool Datastream
–Map Sensor Voltage
• 2) KOEO
• 3) Attach Vacuum Pump To Map
Sensor Vacuum Port
• 4) 0 Vacuum, 3.9 To 4.7 Volts
• 5) 18 To 20 Inches Vacuum, .8 To
1.5 Volts
Cranking Vacuum/Pressure
• Cranking Vacuum can be tested
using the MAP Sensor
• The voltage or pressure should
decrease in response to vacuum
Reaction Testing
• Testing the TPS against the MAP
sensor shows the response of the
sensors
• They should follow each other.
• This test will verify CAM to
Crankshaft timing
• This test will verify if the TPS
sticks when closing
TPS Quick Specs
GM Throttle Body Injection
.55 to .75 volts=0% closed
Cold / Warm
GM Port Fuel Injection
.29 to .58 volts=0% closed cold
.4 to .58 volts closed=0% warm idle
running
Ford
.8 to 1 volt
Wide Open Throttle 4.3 minimum
Chrysler
.6 to 1.1 volts
Wide Open Throttle 2.6 volts above
stored minimum TPS
TPS Sweep Test
• 1) KOEO
• 2) Scan Tool Datastream
–TPS
• 3) Open And Close TPS, Smooth
Linear Rise
Two Wire Sensor Testing
• Check for Voltage supply
– Voltage supply must be above 4.6
volts
• Scan tool should read cold –40°F
• Short the pins in the connector together
– Reading on DVOM should be less
than .050 mv
• Scan tool reading should be above
260°F
Three Wire Testing
• Check for Voltage Reference
– Range 4.9 to 5.1 volts
• Check for proper ground
– Red lead at sensor ground and black lead
at battery ground, voltage should read
under .050mv
• Short VREF pin and Signal pin together
– Datastream should read the same as
VREF
• Short signal pin and ground pin together
– Datastream should read zero
Cylinder Misfire Testing
• Engine at operating temperature
• Vehicle at cruise speed
• Monitor rear or post HO2S
– Base line voltage .430mv to .470mv
• Rear HO2S voltage high
– Secondary Ignition miss fire
• Rear HO2S voltage low
– Lean Injector miss fire
Catalyst Test 1
• 1) Engine at Operating Temperature
• 2) All Basic Engine Functions Must Be in
Good Working Order
• 3) Raise Engine Rpm to 2000 and Hold Steady
• 4) 3 Minutes Minimum
• 5) Monitor HO2S Sensors Upstream and
Downstream
• 6) Upstream Should Be Swinging Rich to Lean
• 7) Downstream Should Be Steady With Small
Swing of 430 to 470 Mv
Catalyst Efficiency Monitor
Pre-HO2S
Post-HO2S
Upstream HO2S
S1
Downstream HO2S
S2
800 mv
470 mv
450 mv
450 mv
430 mv
200 mv
Catalyst Test 2
• To test for a plugged Catalytic Converter, graph MAP
Voltage
• With the engine running at 2000 RPM for 3 minutes
note what MAP Voltage is, it should be around 1.2 to
1.6 Volts
• Snap the throttle to wide open from 2000 RPM
• MAP Voltage will rise from 2000 RPM at wide open
throttle to approximately 3.8 to 4.2 Volts
• When the engine returns to idle MAP Voltage should
return to 1.2 to 1.6 Volts in less than 3 seconds
• If it takes longer than 3 seconds the Catalytic Converter
maybe plugged
Charging Systems Test
• 1) KOER
• 2) At Idle verify Battery Volts
• 3) At 2000 RPM verify Battery
Volts
–Turn all accessories on
• Voltage should rise to 14 to 15
volts
Cranking Voltage Test
•
•
•
•
Record the voltage
Put the engine in Clear Flood mode
Crank the engine for 15 seconds
Cranking Voltage should not go
under 9.6
• Recovery Voltage should come
close to the recorded voltage in
less than 7 seconds