5.7 Valve adjust 99 Tahoe

[retorq]

I've seen guys do that before but not on a center bolt cover ...

 

[DevilDog]

man...you sure you wasnt the old man i was talking about ?? , yep very similar to what he had except his was just cut out, not drilled.

 

[inthechateau]

I still have my old cut out for older SBC's. Cut the slot out of the center, pop riveted an old lether belt over the slot to keep oil from squirting out and just cut slits open enough to get to the rocker bolts. Worked like a charm. Going to try the same thing not sure of clearance with mount bolt holes though. Will share pic's when I get it cut.

 

[retorq]

man...you sure you wasnt the old man i was talking about ?? , yep very similar to what he had except his was just cut out, not drilled.

I'm sure.

 

[inthechateau]

With out adjusting the valves any since engine sounds pretty good i ran it for a while tonight. Was low on fuel so i dumped 4 gals of fresh fuel in. After it warmed up it throwed 5 codes at me.
1. P0300-Misfire
2. P0102-MAF
3. P1351-No Start
4. P0141-O2 sensor bank 1 sensor 2
5. P0300-Misfire second code

I set the scanner down and accidently leaned on the clear code function button and oppsy all gone. It was a little hesitant to restart but once it did it was kind of sloppy and hard to idle for a few minutes. Cleared up and the codes did not return after 15 minutes of running. It got late so I called it quits before neighbors call the cops(noise ordanance).

Not sure where to start on all of this but will dive in tomorrow after work I guess. Any hints would be apreciated.

 

[SunlitComet]

wow bad gas or something.

let me just throw this out there for now. and print all this out before the pictures change.


1.

Powertrain Controls Diagnosis

Circuit Description
The Crankshaft Position (CKP) Sensor is the primary input to determine if misfire is occurring. Engine misfire is detected by monitoring crankshaft speed variations between cylinders. If a crankshaft deceleration occurs during a combustion or power stroke, the Control Module (PCM/VCM) will compare this change in crankshaft speed to the previous cylinder. If the crankshaft speed change is more than a maximum allowable speed, the misfire is detected. Misfire may occur in a specific cylinder or all cylinders randomly.

When an engine is misfiring, brief decelerations in crankshaft rotational speed will be detected by the CKP. The Control Module determines which cylinder has misfired based upon the Camshaft Position CMP Sensor input. Misfire data is stored for each cylinder in separate accumulators. After 100 combustion events, the misfire totals are compared to a calibrated maximum number. If the misfire is excessive, a this DTC will set.

Conditions for Running the DTC

• If start-up ECT temperature is below minus 7°C (20°F), misfire detection is delayed until ECT temperature is more than 21°C (70°F). If start-up ECT temperature is more than minus 7°C (20°F), misfire detection begins after a 5 second delay.
• No active vehicle speed DTCs
• No active TP sensor DTCs
• No active MAF sensor DTCs
• No active camshaft sensor DTCs
• No active crankshaft sensor DTCs
• The fuel level is more than 10 percent
• The system voltage is between 11-16 volts
• The engine speed is between 450-5000 RPM
• The throttle position is steady within 2 percent for 100 ms

Conditions for Setting the DTC
The VCM detects a deceleration in the crankshaft speed characteristic of either an emission type misfire or a catalyst damaging type misfire.

Action Taken When the DTC Sets
If the VCM determines that the engine misfire is significant enough to have a negative impact on emissions, the VCM turns ON the MIL after the misfire has been detected on 2 non-consecutive trips under the same operating conditions. If the misfire is severe enough that catalytic converter damage could result, the MIL flashes while the misfire is present.

Conditions for Clearing the MIL/DTC

• The Control Module turns OFF the MIL after 3 consecutive drive trips when the test has Run and Passed.
• A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles (coolant temperature has risen 22°C (40°F) from the start-up coolant temperature and the Engine Coolant Temperature is more than 70°C (158°F) during the same ignition cycle).
• Use the scan tool Clear Information function.

Diagnostic Aids
The Misfire Index counts the number of misfires. The scan tool can monitor the Misfire Index. There is a current and history misfire counter for each cylinder. Use the current misfire counter in order to determine which cylinder is misfiring or use the history misfire counter for misfires that are not currently present. Many different conditions could cause an intermittent misfire.

Check for the following conditions:

• Check the IC control circuit for an intermittent short to ground.
• Check the spark plug wires and the coil wire for the following conditions:
• Ensure that the spark plug wires are securely attached to the spark plugs and the distributor cap.
• Check the wire routing in order to ensure that crossfiring is not occurring.
• If the misfire occurs when the weather is damp, the problem could be due to worn plug wires.
• Check for contaminated or a low fuel level and the following conditions:
• Check the fuel condition and quality. Dirty or contaminated fuel could cause a misfire condition. Refer to Alcohol/Contaminants-in-Fuel Diagnosis.
• If the fuel level is low, the fuel pump may draw air into the fuel rail, causing a stumble and possible misfire condition. Check the fuel trim numbers in the freeze frame to determine if this has occurred. It would be likely if the short term fuel number was above +20
• A restricted fuel filter can also cause a misfire.

Sticking intake or exhaust valves on engines with a misfire when cold.

Check HO2S for abnormal voltage readings. Check for a vacuum leak as a possible cause of the engine misfire.

An intermittent may be caused by any of the following conditions:

• A poor connection
• Rubbed through wire insulation
• A broken wire inside the insulation

Thoroughly check any circuitry that is suspected of causing the intermittent complaint. Refer to Intermittents and Poor Connections Diagnosis. See: Powertrain Management\Computers and Control Systems\Testing and Inspection\Symptom Related Diagnostic Procedures

Test Description
The numbers below refer to the step numbers on the diagnostic table.

1. The misfire is considered random on all cylinders if while viewing the misfire fire counters in the misfire data list, the misfire seems to move to different cylinders.
2. The misfire is considered consistent if the misfire is occurring on the same cylinder(s) consistently.
3. When checking the spark at the spark plug wires, the spark should be consistent. A few sparks then nothing is no spark.

 

[SunlitComet]

P0102

Circuit Description
The Mass Air Flow (MAF) sensor is an air flow meter. The Control Module (PCM/VCM) supplies the MAF sensor a signal circuit. An ignition voltage is supplied to the MAF sensor by an independent circuit. A ground is supplied to the MAF sensor by an independent circuit. The MAF sensor heats a wire element, or grid, within the MAF sensor in order to a calculated temperature. As inlet air flows across and cools the grid, the MAF sensor increases current flow to the grid in order to maintain a constant grid temperature. The MAF sensor convents the grid current flow into a frequency signal. The Control Module converts the MAF signal frequency into a grams per second value. During low air flow rates, such as at engine idle, the MAF sensor produces a low frequency signal. During high air flow rates, such as Wide Open Throttle-road load, the MAF sensor increases the frequency signal. The Control Module monitors the MAF sensor signal frequency to calculate the flow and mass of the air entering the engine.

This DTC is designed to detect an unusually low MAF sensor signal frequency. If a MAF sensor frequency is detected by the VCM below the possible range of a normally operating MAF sensor, this DTC will be set.

Conditions for Running the DTC

• The engine is running
• The engine run time is more than 0.4 seconds
• The engine speed is more than 300 RPM
• The system voltage is more than 8 volts

Conditions for Setting the DTC
The MAF frequency is 10 Hz or less for more than 1 second.

Action Taken When the DTC Sets

• The Control Module illuminates the Malfunction Indicator Lamp (MIL) if a failure is detected during 2 consecutive key cycles.
• The Control Module will set the DTC and records the operating conditions at the time the diagnostic fails. The Control Module stores the failure information in the scan tools Freeze Frame and/or the Failure Records.

Conditions for Clearing the MIL/DTC

• The Control Module turns OFF the MIL after 3 consecutive drive trips when the test has Run and Passed.
• A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles (coolant temperature has risen 22°C (40°F) from the start-up coolant temperature and the Engine Coolant Temperature is more than 70°C (158°F) during the same ignition cycle).
• Use the scan tool Clear Information function.

Diagnostic Aids
Check for the following conditions:

• A misrouted harness. Inspect the MAF sensor harness in order to ensure that it is not routed too close to high voltage wires such as spark plug leads.
• A damaged harness. Inspect the wiring harness for damage. If the harness appears to be OK, observe the scan tool while moving the connectors and the wiring harnesses related to the MAF sensor. A change in the display indicates the location of the fault.
• A plugged intake air duct or filter element. A Wide Open Throttle acceleration from a stop should cause the Mass Air Flow displayed on a scan tool to increase from about 4-7 g/s at idle to 100 g/s or more at the time of the 1-2 shift. If not, check for a restriction.

An intermittent may be caused by any of the following conditions:

• A poor connection
• Rubbed through wire insulation
• A broken wire inside the insulation

Thoroughly check any circuitry that is suspected of causing the intermittent complaint. Refer to Intermittents and Poor Connections Diagnosis. See: Powertrain Management\Computers and Control Systems\Testing and Inspection\Symptom Related Diagnostic Procedures

Test Description
The numbers below refer to step numbers on the diagnostic table.

1. This step verifies that the problem is present at idle.

1. A voltage reading of less than 4 or more than 6 volts at the MAF sensor signal circuit indicates a malfunction in the wiring or a poor connection.
2. This step verifies that the ignition positive voltage and a good ground are available at the MAF sensor.

1. This step determines if the fuse is open. If the fuse is open, locate and repair the short to ground in the ignition positive voltage circuit.

---------- Post added at 08:12 PM ---------- Previous post was at 08:11 PM ----------

P1351

Circuit Description
The Enhanced Ignition system uses the Crankshaft Position sensor in order to provide a timing input to the Control Module (PCM/VCM). Ignition Control (IC) spark timing for each cylinder based on this input. The Control Module provides the Ignition Timing Signal to the Ignition Control Module (ICM) to control the Ignition Coil. Each timing pulse detected by the ICM allows it to energize the Ignition coil. A large Secondary ignition voltage is induced in the secondary coil by the primary coil. This high voltage is switched to the correct spark plug by the distributor.

This DTC will set if the VCM detects an unusually high voltage on the ignition timing signal circuit.

Conditions for Running the DTC

• The ignition control is enabled
• The engine speed is less than 250 RPM

Conditions for Setting the DTC
The Ignition Control voltage is more than 4.9 volts

Action Taken When the DTC Sets

• The Control Module illuminates the Malfunction Indicator Lamp (MIL) the first time the diagnostic runs and fails.
• The Control Module will set the DTC and records the operating conditions at the time the diagnostic fails. The Control Module stores the failure information in the scan tools Freeze Frame and/or the Failure Records.

Conditions for Clearing the MIL/DTC

• The Control Module turns OFF the MIL after 3 consecutive drive trips when the test has Run and Passed.
• A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles (coolant temperature has risen 22°C (40°F) from the start-up coolant temperature and the Engine Coolant Temperature is more than 70°C (158°F) during the same ignition cycle).
• Use the scan tool Clear Information function.

Diagnostic Aids
Intermittent test - If the connections and the harness check OK, monitor a digital voltmeter connected between VCM terminal C3 pin 9 and C4 pin 18 while moving related connectors and wiring harness. If the failure is induced, the voltage reading will change. This may help to isolate the location of the malfunction.

An intermittent may be caused by any of the following conditions:

• A poor connection
• Rubbed through wire insulation
• A broken wire inside the insulation

Thoroughly check any circuitry that is suspected of causing the intermittent complaint. Refer to Intermittents and Poor Connections Diagnosis. See: Powertrain Management\Computers and Control Systems\Testing and Inspection\Symptom Related Diagnostic Procedures

Test Description
The numbers below refer to the step numbers in the diagnostic table.

1. This determines if the DTC is an intermittent.
2. This step checks if the IC signal from the VCM is available at the Ignition Control Module.

 

[SunlitComet]

Under 8600 GVW Without C6P

Circuit Description
The Heated Oxygen Sensor (HO2S) is a sensor designed to create a voltage relative to the oxygen content in the engine exhaust stream. The Control Module (PCM/VCM) supplies the HO2S with signal High and Low circuits. Ignition voltage and ground is supplied to the HO2S heater by independent circuits. The oxygen content of the exhaust indicates when the engine is operating lean or rich. When the HO2S detects that the engine is operating rich, the signal voltage is high, and decreases the signal voltage as the engine runs leaner. This oscillation above and below the bias voltage, sometimes referred to as activity or switching, can be monitored with the HO2S signal voltage.

The HO2S contains a heater that is necessary in order to quickly warm the sensor to operating temperature and maintain the operating temperature during extended idle conditions. The HO2S needs to be at a high temperature in order to produce a voltage. Once the HO2S has reached operating temperature, the Control Module monitors the HO2S bias, or reference, voltage as well as the HO2S signal voltage for closed loop fuel control. During normal Closed Loop fuel control operation, the Control Module will add fuel (enriches the mixture) when the HO2S detects a lean exhaust content and subtract fuel (leans-out the mixture) when the HO2S detects a rich exhaust condition.

Certain vehicle models utilize an oxygen sensor after the catalyst converter in order to monitor catalyst efficiency.

This DTC determines if the HO2S is functioning properly by checking for an adequate number of HO2S voltage transitions above and below the bias range of 300-600 mV. This DTC sets when the VCM fails to detect a minimum number of voltage transitions above and below the bias range during the test period. Possible causes of this DTC are listed below.

• An open or a short to voltage on either the HO2S signal or HO2S low circuits.
• A malfunctioning HO2S.
• A problem in the HO2S heater or its circuit.
• A poor HO2S ground.

This DTC determines if the post-converter HO2S heater circuit is functioning properly by monitoring the amount of time required for the HO2S to reach operating temperature. This DTC sets when the VCM fails to detect HO2S voltage transitions above and below the bias range within a specified amount of time. Possible cause of this DTC are listed below.

• An open circuit in either the HO2S ignition positive voltage or the HO2S heater ground circuits
• An HO2S heater element problem

Conditions for Running the DTC

Important: This test is void if the system voltage remains outside the specified range for more than 4 seconds

• The system voltage is between 11.7-18 volts
• The MAF is less than 35 g/s
• The engine run time is more than 2 seconds
• The ECT is less than 33°C (91°F)
• The IAT is less than 33°C (91°F)
• The difference between the ECT and IAT is 5°C (9°F) or less

Conditions for Setting the DTC
The HO2S sensor voltage remains within 150 mV of the start-up voltage for 245 seconds after cold start.

Action Taken When the DTC Sets

• The Control Module illuminates the Malfunction Indicator Lamp (MIL) if a failure is detected during 2 consecutive key cycles.
• The Control Module will set the DTC and records the operating conditions at the time the diagnostic fails. The Control Module stores the failure information in the scan tools Freeze Frame and/or the Failure Records.

Conditions for Clearing the MIL/DTC

• The Control Module turns OFF the MIL after 3 consecutive drive trips when the test has Run and Passed.
• A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles (coolant temperature has risen 22°C (40°F) from the start-up coolant temperature and the Engine Coolant Temperature is more than 70°C (158°F) during the same ignition cycle).
• Use the scan tool Clear Information function.

Diagnostic Aids
Check for the following:

An intermittent may be caused by any of the following conditions:

• A poor connection
• Rubbed through wire insulation
• A broken wire inside the insulation

Thoroughly check any circuitry that is suspected of causing the intermittent complaint. Refer to Intermittents and Poor Connections Diagnosis. See: Powertrain Management\Computers and Control Systems\Testing and Inspection\Symptom Related Diagnostic Procedures

Test Description
The number(s) below refer to the step number(s) on the Diagnostic Table.

1. As the heater warms the oxygen sensor to operating temperature, the HO2S will output a voltage in relation to the amount of oxygen in the exhaust. With the ignition ON and the engine OFF the exhaust usually contains a high oxygen content. With the engine OFF the HO2S voltage will usually decrease from the initial: (bias) voltage due to the high oxygen content.

1. This step checks for proper HO2S heater ignition feed and ground supply.
2. This step checks for proper VCM and signal circuit operation.

 

[inthechateau]

Dang, just ran out of printer paper...........trying screen print to file. Thanks Sunlit. You are the guru fella....