lots of problems, please help

[donwaun4998]

Hello, new b here with a 99 Yukon 4x4 slt.

I have had multiple codes including ignition current high, multiple cylinder missfire, and misfire cylinder 7. Also bank one running lean. I have replaced the ignition module, coil, distributer cap, and rotor, plugs, wires, fuel filter, o2 sensors, and finally the whole spyder fuel injection system.

Idle is rough, and using alot of gas. I'm running out of time and money, any suggestions?

 

[SunlitComet]

Would you mind posting the codes please?

 

[donwaun4998]

p0300, P0307, Po171, and also for one for ignition current high, I don't remember what the code was for that, but I'm about to jump off a bridge. Rough idle, carbon in exhaust, white smoke. Spark plugs on bank one all carbon fouled, fuel trim 2 is low, fuel pump is new though. Tested for vacume leaks.

---------- Post added at 10:02 PM ---------- Previous post was at 09:51 PM ----------

Any ideas from anyone would be greatly appreciated, maybe there are things I don't know to check, or overlooked.

 

[SunlitComet]

SO far all of them point to this so look into the below and details on each code also follow:


Important Information - PIP 3056 Subject: 97-05 Vehicles with 4.8 5.3 5.7 and 6.0 Gen III V8 Engines and Misfires on One Bank - kw CEL diagnostics driveability DTC P0171 P0172 P0174 P0175 P0300 P0301 P0302 P0303 P0304 P0305 P0306 P0307 P0308 #PIP3056 - (07/12/2004)

Models: (00-05 Cadillac Escalade - C6 and K6) and (02-05 Chevrolet Avalanche - C1, C2 K1 and K2) and (99-05 Chevrolet Silverado - C1, C2 K1 and K2) and (00-05 Chevrolet Suburban - C1, C2, K1 and K2) and (00-05 Chevrolet Tahoe - C1 and K1) and (99-05 GMC Sierra C1, C2 K1 and K2) and (00-05 GMC Yukon - C1, C2, K1 and K2) and (03-05 Chevrolet Express G1, G2, G3, H1, H2 ) and (03-05 GMC Savana G1, G2, G3, H1, H2 ) and (04-05 Buick Rainier S1, T1 ) and (03-05 Chevrolet Trail Blazer EXT S1, T1 ) and (03-05 GMC Envoy XL XUV S1, T1 ) and (03-05 Hummer H2) and (04-05 Cadillac CTS-V DB) and (98-02 Chevrolet Camaro FB) and (97-04 Chevrolet Corvette YB) and (98-02 Pontiac Firebird FB) and (04-05 Pontiac GTO VB)

The following diagnosis might be helpful if the vehicle exhibits the described symptoms.

Condition/Concern:
Check Engine Light with a P0300 due to 2 - 4 cylinders misfiring on the same bank of the engine. DTCs P0171, P0172, P0174 or P0175 may also set for the misfiring bank.

Recommendation/Instructions:
If the published misfire diagnostic does not isolate the cause, perform the following suggestions as necessary:

• Perform a fuel injector balance test for all 8 cylinders. If a fuel injector concern exists, it is possible to misfuel an entire bank of the engine, causing multiple cylinders on the same bank to misfire even though the root cause is a single fuel injector.
• Inspect O2 sensor connections on the misfiring bank for corrosion or water intrusion. If water intrusion is found on the right bank, it may be due to the AC Evaporator Condensation dripping onto the O2 sensor harness. If this condition is found, reposition and shield the harness to prevent a repeat concern and repair the connections.
• Check for excessive exhaust backpressure using the restricted exhaust diagnosis.
• Swap the Position 1 O2 sensors side to side to see if the misfires move to the other bank of the engine. If so, replace the O2 sensor.

Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

NOTE: GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition.

 

[SunlitComet]

Powertrain Controls Diagnosis

Circuit Description
In order to provide the best possible combination of driveability, fuel economy, and emission control, the vehicle uses a closed loop air and fuel metering system. While in closed loop, the VCM monitors the oxygen sensor signal voltage. The VCM adjusts the fuel delivery based on the signal voltage. The long and short term fuel values, which a scan tool can monitor, indicate a change made to the fuel delivery. Ideal fuel trim values are around 0% (128 counts); if the oxygen sensor signal indicates a lean condition, the VCM adds fuel. This results in fuel trim values above 0%. If the oxygen sensor detects a rich condition, the fuel trim values will read below 0%. This indicates that the VCM is reducing the amount of fuel delivered. The VCM sets this DTC when an excessively lean condition is detected.

Conditions for Running the DTC

• No active O2 sensor DTCs
• No active TP sensor DTCs
• No active MAP sensor DTCs
• No active EGR sensor DTCs
• No active EVAP system sensor DTCs
• No active ECT sensor DTCs
• No active MAF sensor DTCs
• No active IAT sensor DTCs
• No active VS sensor DTCs
• No System Voltage DTCs
• No active misfire DTCs
• Throttle position less than 70%
• Engine speed is between 575 and 4,000 RPM
• The BARO greater than 70 kPa
• The ECT is between 75 and 114°C (167-237°F)
• The MAP is between 22 and 85 kPa.
• The IAT is between 8 and 76°C (46-169°F)
• The MAF is between 3 and 85 g/s
• The vehicle speed less than 85 MPH

Conditions for Setting the DTC
The average of the short term fuel trim values over a period of 120 seconds indicates that a lean condition is present.

Action Taken When the DTC Sets

Important: To complete a trip cycle for the fuel trim diagnostic, the fuel trim diagnostic test must enable and run according to the above enable criteria and the conditions for setting. A trip is not considered complete until the fuel trim diagnostic has run by the VCM.

When the current DTC initially sets, a software flag indicating an emissions related fault sets for 3 trips. The flag will clear provided the lean condition is no longer present. However, if the VCM detects the conditions for setting the current DTC during a trip while the flag is still set, the VCM turns on the MIL (Malfunction Indicator Lamp). The MIL remains on during all of the subsequent trips until the DTC has been cleared by service or the lean condition has not been detected and the conditions for checking the fuel trim have been met for 3 consecutive trips.

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
If using the diagnostic tables does not isolate the problem, try monitoring the LT fuel trim and fuel trim cell while operating the vehicle under various loads. This may isolate the condition which caused the setting of the current DTC.

A condition that causes the DTC P0300 Engine Misfire Detected may also set the current DTC; conversely an extremely lean condition which sets the current DTC can cause a misfire at idle and the DTC P0300 to set. If the cause of the current DTC cannot be determined and the DTC P0300 is also set, refer to DTC P0300 Engine Misfire Detected. See: P0300

Typical Fuel Trim Values
The Fuel Trim Values table indicates the typical fuel adjustment values as displayed on a scan tool. Negative values (Rich condition) indicate that the injector pulse width is being decreased in order to lean out the fuel mixture. Positive values (Lean condition) indicate that the injector pulse width is being increased in order to richen the fuel mixture.

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


2-A more negative value indicates the VCM is leaning the fuel mixture (Rich condition), and a more positive value indicates the VCM is richening the fuel mixture (Lean condition)

5-Visually and physically check the items that can cause a lean condition in order to determine the cause of the DTC being set.

---------- Post added at 07:50 PM ---------- Previous post was at 07:47 PM ----------

Important Information - PIP 3056 Subject: 97-05 Vehicles with 4.8 5.3 5.7 and 6.0 Gen III V8 Engines and Misfires on One Bank - kw CEL diagnostics driveability DTC P0171 P0172 P0174 P0175 P0300 P0301 P0302 P0303 P0304 P0305 P0306 P0307 P0308 #PIP3056 - (07/12/2004)

Models: (00-05 Cadillac Escalade - C6 and K6) and (02-05 Chevrolet Avalanche - C1, C2 K1 and K2) and (99-05 Chevrolet Silverado - C1, C2 K1 and K2) and (00-05 Chevrolet Suburban - C1, C2, K1 and K2) and (00-05 Chevrolet Tahoe - C1 and K1) and (99-05 GMC Sierra C1, C2 K1 and K2) and (00-05 GMC Yukon - C1, C2, K1 and K2) and (03-05 Chevrolet Express G1, G2, G3, H1, H2 ) and (03-05 GMC Savana G1, G2, G3, H1, H2 ) and (04-05 Buick Rainier S1, T1 ) and (03-05 Chevrolet Trail Blazer EXT S1, T1 ) and (03-05 GMC Envoy XL XUV S1, T1 ) and (03-05 Hummer H2) and (04-05 Cadillac CTS-V DB) and (98-02 Chevrolet Camaro FB) and (97-04 Chevrolet Corvette YB) and (98-02 Pontiac Firebird FB) and (04-05 Pontiac GTO VB)

The following diagnosis might be helpful if the vehicle exhibits the described symptoms.

Condition/Concern:
Check Engine Light with a P0300 due to 2 - 4 cylinders misfiring on the same bank of the engine. DTCs P0171, P0172, P0174 or P0175 may also set for the misfiring bank.

Recommendation/Instructions:
If the published misfire diagnostic does not isolate the cause, perform the following suggestions as necessary:

• Perform a fuel injector balance test for all 8 cylinders. If a fuel injector concern exists, it is possible to misfuel an entire bank of the engine, causing multiple cylinders on the same bank to misfire even though the root cause is a single fuel injector.
• Inspect O2 sensor connections on the misfiring bank for corrosion or water intrusion. If water intrusion is found on the right bank, it may be due to the AC Evaporator Condensation dripping onto the O2 sensor harness. If this condition is found, reposition and shield the harness to prevent a repeat concern and repair the connections.
• Check for excessive exhaust backpressure using the restricted exhaust diagnosis.
• Swap the Position 1 O2 sensors side to side to see if the misfires move to the other bank of the engine. If so, replace the O2 sensor.

Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

NOTE: GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition.

 

[SunlitComet]

Important Information - PIP 3081 Subject: SES Light and P0300 When Towing , Cruising Uphill or on Hard Acceleration - 4.3 5.0 5.7 accelerate cruise cylinderhead RPO L30 L31 L35 LF6 LU3. DTC P0300 P0301 P0302 P0303 P0304 P0305 P0306 P0307 P0308 PIP3081 - (07/23/2004)

Models: (96-02 Chevrolet Astro) and (96-02 GMC Safari) and (96-00 Old Body Style Chevrolet Suburban) and (96-00 Old Body Style Chevrolet Tahoe) and (96-02 Chevrolet Express) and (96-00 GMC Yukon) and (96-00 Chevrolet Old Body Style C/K Truck) and (96-00 GMC Old Body Style C/K Truck) and (96-02 GMC Savana) and (96-99 P32 Cab and Chassis) and (96-02 Chevrolet S-10) and (99-02 Chevrolet Silverado with 4.3L V-6 Engines (96-02 GMC Sonoma) and (96-02 GMC Sierra with 4.3L V-6 Engines).

The following diagnosis might be helpful if the vehicle exhibits the symptom described.

Condition/Concern:
The vehicle may exhibit a SES Light due to a P0300 and misfire. If the misfire is related to the information below, it will typically happen while cruising uphill, pulling a trailer or on hard acceleration and then stop misfiring shortly after returning to an idle. Typically, cylinders 3,4,5 or 6 will be the ones to experience this.

Recommendation/Instructions:
If the P0300 diagnostics did not isolate a concern, the following may help:
Remove the valve cover, valve springs and valve seals on the effected cylinder or cylinders. A small wire tie or rubber bands can be placed in the valve stem keeper groove to prevent the valve from falling into the cylinder. Rotate the valve while moving it up and down in the guide to see if it binds. If a binding valve is found, remove both cylinder heads and use either of the following methods to increase the stem to guide clearance:

• Send the head out to a machine shop and advise them to increase the valve stem to guide clearance to 0.002 inch per guide.
• Hone the guide with a 9 mm hone, such as Snap On BCG249, until a clearance of 0.002 inch is obtained. This will usually take about 4 strokes of the hone.

Reassemble the cylinder heads using new valve seals.

Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

NOTE: GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

 

[SunlitComet]

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: Symptom Related Diagnostic Procedures

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


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.

6-The misfire is considered consistent if the misfire is occurring on the same cylinder(s) consistently.

7-When checking the spark at the spark plug wires, the spark should be consistent. A few sparks then nothing is no spark.

---------- Post added at 07:55 PM ---------- Previous post was at 07:53 PM ----------

p0307 is just singling out cylinder 7(left bank rear at firewall) as misfire in it self. It might probably be happening there more.

---------- Post added at 07:56 PM ---------- Previous post was at 07:55 PM ----------

Try the o2 sensor swap first.

---------- Post added at 07:56 PM ---------- Previous post was at 07:56 PM ----------

And print this out very soon as the charts will change.