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Gizm0815
04-01-2007, 09:10 PM
replaced my lim this weekend an i have fixed all but one problem. the car now idles bad like it has a misfire almost i never pulled the plugs and all the wires are back on the coil pack, yes i checked them. i know i threw a code since i have a ses light i havent had it read yet. im also getting a high pitched wistle sounds like a vac line but they are all on tight. the whistle goes away if i rev up above about 1500-2000rpm. i did replace my fpr while it was out since my old one went bad. i have a mpracing tune on my pcm, im wondering if the pcm just needs to learn and compensate with the new fpr and thats causing this problem. any help of ideas of what to look for would be great i cant get a code read till tomarrow afternoon.

thanks,
joe

drumking1721
04-01-2007, 09:31 PM
When i put in my new FPR i didnt have that issue

Gizm0815
04-02-2007, 08:55 AM
bump anyone got some ideas?

Sprucegagt
04-02-2007, 10:25 AM
If you can hear a whistle sound and have a bad idle, then you have a vacuum leak. Check all your hoses again and check the UIM gasket and around each fuel injector.

Gizm0815
04-02-2007, 10:51 AM
i never pulled my injectors. i left them in the manifold. but ill look around again for a vacume leak

gectek
04-02-2007, 11:08 AM
usually the vac leak is from the TB, if u used an old gasket, or didnt get the bolts tight enough, just make sure they are all torqued down

Gizm0815
04-02-2007, 11:56 AM
i did use a new gasket ill check th ebolts again. got the codes read and cleared i have a P0300 and a P-171 code

lvemy3100
04-02-2007, 02:02 PM
DTC P0171 Fuel Trim System Lean
Circuit Description
To provide the best possible combination of driveability, fuel economy, and emission control, a closed loop air/fuel metering system is used. While in closed loop, the Powertrain Control Module (PCM) monitors the HO2S 1 signal and adjusts fuel delivery based upon the HO2S signal voltages. A change made to fuel delivery will be indicated by the Long and Short Term FT values which can be monitored with a scan tool. Ideal fuel trim values are around 0 percent. If the HO2S signals are indicating a lean condition the PCM will add fuel, resulting in fuel trim values above 0 percent. If a rich condition is detected, the fuel trim values will be below 0 percent, indicating that the PCM is reducing the amount of fuel delivered. If an excessively lean condition is detected, the PCM will set DTC P0171. The PCMs maximum authority to control long term fuel trim allows a range between -30 percent and 24 percent. The PCMs maximum authority to control short term fuel trim allows a range between -27 percent and 27 percent. The PCM monitors fuel trim under various operating conditions (fuel trim cells) before determining the status of the fuel trim diagnostic. The fuel trim cells are as follows:

Cell
Purge ON
Purge OFF

Idle (Cell 0)
X
--

Decel (Cell 1)
X
--

Normal (Cell 2)
X
--

Accel (Cell 3)
--
--

High Flow (Cell 4)
--
--

Long Term FT average more than +22 percent

Short Term FT more than +3 percent


The vehicle may have to be operated in all of the above conditions marked by an X, before the PCM determines fuel trim status. The amount of fuel trim deviates from 0 percent in each cell and the amount that each cell is used directly affects whether or not the vehicle must be operated in all of the cells described above to complete the diagnostic.

Conditions for Running the DTC
No MAF, MAP, TP, ECT, IAT, CKP, CAM sensor, Misfire, Fuel injector, VSS, EST, HO2S, EGR, or EVAP DTCs are set.
Engine coolant temperature between 20C (68F) and 110C (230F).
Intake air temperature is between -18C (0F) and 70C (158F).
Manifold absolute pressure is between 15-85 kPa.
Throttle angle is steady and less than 90 percent.
Vehicle speed is less than 132 km/h (82 mph).
Engine speed is between 600 and 4000 RPM.
Baro is more than 70 kPa.
Air flow is between 3-150 gm/s.
Conditions for Setting the DTC
Long Term FT is at or near maximum authority of 22 percent.
Short Term FT is more than 3 percent.
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.
The PCM will store conditions which were present when the DTC set as Freeze Frame/Failure Records data.
Conditions for Clearing the MIL/DTC
The PCM will turn OFF the malfunction indicator lamp (MIL) during the third consecutive trip in which the diagnostic has run and passed.
The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
The DTC can be cleared by using a scan tool.
Diagnostic Aids
Inspect for the following conditions:

Heated oxygen sensor wiring--The sensor pigtail may be routed incorrectly and contacting the exhaust system.
Faulty PCM to engine block grounds. Refer to Ground Distribution Schematics in Wiring Systems.
Fuel pressure low--The system will go lean if pressure is too low. The PCM can compensate for some decrease. However, if fuel pressure is too low, a DTC P0171 may be set. Refer to Fuel System Diagnosis .
Fuel injectors faulty--Refer to Fuel Injector Balance Test .
Vacuum leaks--Inspect for disconnected or damaged vacuum hoses and for vacuum leaks at the intake manifold, throttle body, EGR system, and crankcase ventilation system. Refer to Symptoms .
Exhaust leaks--An exhaust leak may cause outside air to be pulled into the exhaust gas stream past the HO2S, causing the system to appear lean. Inspect for exhaust leaks that may cause a false lean condition to be indicated. Refer to Inspection Procedure in Engine Exhaust. .
Disconnect the MAF sensor and see if the lean condition is corrected. If so, replace MAF sensor. Refer to Mass Air Flow (MAF) Sensor Replacement .
Fuel contamination--Water, even in small amounts, can be delivered to the fuel injectors. The water can cause a lean exhaust to be indicated. Excessive alcohol in the fuel can also cause this condition. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
Many situations may lead to an intermittent condition. Perform each inspection or test as directed.


Important:
Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.


Loose terminal connection
Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.
Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Refer to Testing for Intermittent and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.
Damaged harness--Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.
Inspect the powertrain control module (PCM) and the engine grounds for clean and secure connections. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.
If the condition is determined to be intermittent, reviewing the Snapshot or Freeze Frame/Failure Records may be useful in determining when the DTC or condition was identified.

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

DTCs other than P0171 may indicate a condition present which may cause a lean condition. If this is the case, repairing the condition which caused the other DTC will most likely correct the DTC P0171.

If the DTC P0171 test passes while the Failure Records conditions are being duplicated, the lean condition is intermittent. Refer to Diagnostic Aids or Symptoms for additional information on diagnosing intermittent problems.

lvemy3100
04-02-2007, 02:41 PM
Cross Injector Wires Causing Misfire - 3.1 3.4 DTC driveability idle LA1 LG8 MIL P0300 P0301 P0302 P0303 P0304 P0305 P0306 performance rough run #PI01740 - (Feb 17, 2004)
Cross Injector Wires Causing Misfire
.

When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.

Condition/Concern:
Misfire at steady state speed and RPM, MIL illuminated, and a P0300 set

Recommendation/Instructions:
If the fuel injector harness has been off, there is now a misfire at steady state speed and RPM and normal diagnostics have failed to identify the cause, suspect crossed fuel injector connectors. Remove the manifold and check the color code of each circuit to verify its routed to the correct injector.

Important: The rear cylinder head is the odd bank (1-3-5), and the front head the even (2-4-6). The numbers cast into the intake make it look the opposite because the runners cross to the other side.

.

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. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms.

Models:
(00 - 04 Buick Century) and (00 - 04 Buick Rendezvous) and (00 - 04 Chevrolet Malibu) and (00 - 04 Chevrolet Impala) and (00 - 04 Chevrolet Monte Carlo) and (00 - 04 Chevrolet Venture) and (00 - 04 Oldsmobile Alero) and (00 - 04 Oldsmobile Silhouette) and (00 - 04 Pontiac Aztek) and (00 - 04 Pontiac Grand Am) and (00 - 04 Pontiac Grand Prix) and (00 - 04 Pontiac Montana)

lvemy3100
04-02-2007, 02:42 PM
Info - Misfire DTCs P0300, P1380, P1381 and Catalytic Converter Damage Due to Installation of Alarm Systems #02-06-05-004A - (Jan 9, 2004)
Misfire DTCs P0300, P1380, P1381 and Catalytic Converter Damage Due to Installation of Alarm Systems
2004 and Prior GM Passenger Cars and Light Duty Trucks

2003-2004 HUMMER H2

2004 and Prior Isuzu Light Duty Trucks

This bulletin is being revised to add the 2004 model year and include specific DTCs in the title line. Please discard Corporate Bulletin Number 02-06-05-004 (Section 06 - Engine/Propulsion System).

General Motors Engineering, in an effort to determine the root cause of catalytic converter damage, has determined that aftermarket alarm systems incorrectly installed in vehicles have the potential to cause misfire codes and damage to the converter. These alarm systems use a circuit interrupt which utilizes the ignition circuit on the vehicles.

These alarm systems utilize mechanical relays and normal vehicle movement can trigger these relays to engage and disengage the ignition circuit while the vehicle is in motion. These disruptions of the ignition circuit, which occur in milliseconds, may cause more fuel to be commanded. Over time, this dumping of fuel on and off again can cause misfire codes and ultimately damage the converter assembly.


Important
Engineering could not identify any alarms that utilize solid state circuitry that would eliminate this concern. Because of this, it has been determined that all alarm systems must be routed through the starter circuit in order to avoid this condition.


Dealers must be aware of this issue and take note of the wiring on vehicles with alarm systems that come in for repair, particularly for catalytic converter damage that seem to have no known root cause.

lvemy3100
04-02-2007, 02:44 PM
DTC P0300 Engine Misfire Detected




Circuit Description
The Powertrain Control Module (PCM) has the ability to detect a misfire by monitoring the 3X reference from the ignition control (IC) module and camshaft position input signals from the camshaft position (CMP) sensor. The PCM monitors crankshaft speed variations (reference period differences) to determine if a misfire is occurring.

If 2 percent or more of all cylinder firing events are misfires, emission levels may exceed mandated standards. The PCM determines misfire level based on the number of misfire events monitored during a 200 engine revolution test sample. The PCM continuously tracks 16 consecutive 200 revolution test samples. If 22 or more misfires are detected during any 10 of the 16 samples, DTC P0300 will set. If the misfire is large enough to cause possible three-way catalytic converter damage, DTC P0300 may set during the first 200 revolution sample in which the misfire was detected. In the case of a catalyst damaging misfire, the MIL will flash to alert the vehicle operator of the potential of catalyst damage.

Conditions for Running the DTC
No TP, MAP, ECT, CKP, CMP, MAF sensor, or VSS DTCs set
Engine speed between 525-5900 RPM
System voltage between 9.0-18.0 volts
The ECT indicates an engine temperature between -6C (21F) and 125C (253F)
Throttle angle steady
Conditions for Setting the DTC
The PCM is detecting a crankshaft RPM variation indicating a misfire sufficient to cause three-way catalytic converter damage or emissions levels to exceed mandated standard.

Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.
The PCM will store conditions which were present when the DTC set as Freeze Frame/Failure Records data.
Conditions for Clearing the MIL/DTC
The PCM will turn OFF the malfunction indicator lamp (MIL) during the third consecutive trip in which the diagnostic has run and passed.
The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
The DTC can be cleared by using a scan tool.
Diagnostic Aids
The scan tool provides information that can be useful in identifying the misfiring cylinder. If the DTC P0300 is currently stored as Test failed since code clear, the misfire history counters (Misfire History, number 1-6) will still contain a value that represents the level of misfire for each cylinder.

A misfire DTC may set if components that affect the crankshaft position sensor have recently been replaced, and the CKP System Variation Learn Procedure has not been performed. If the diagnostic table does not identify a problem then perform the CKP System Variation Learn Procedure . The Crankshaft Position Variation Learn Procedure should be performed if any of the following conditions are true:

The scan tool displayed misfire counter values (Misfire History number 1 through 6) can be useful in determining whether the misfire is isolated to a single cylinder or to a cylinder pair (cylinders that share an ignition coil-1/4, 2/5, 3/6.) If the largest amount of activity is isolated to a cylinder pair, inspect for the following conditions:

The PCM has been replaced.
DTC P1336 is set.
The engine has been replaced.
The crankshaft has been replaced.
The crankshaft harmonic balancer has been replaced.
The crankshaft position sensor has been replaced.
Secondary Ignition Wires--Inspect wires for affected cylinder pair for disconnected ignition wires or for excessive resistance (the wires should measure should be 600 ohms per foot (1 968 ohms per meter).
Damaged Or Faulty Ignition Coil--Inspect for cracks, carbon tracking or other damage. Also inspect coil secondary resistance. Secondary resistance should be between 5000 ohms and 8000 ohms (5K ohms and 8K ohms).
Substitute a Known Good Coil--Swap ignition coils and retest. If the misfire follows the coil, replace the ignition coil.
If the misfire is random, inspect for the following conditions:

System Grounds--Ensure all connections are clean and properly tightened.
MAF: A mass air flow (MAF) sensor output that causes the PCM to sense a lower than normal air flow will cause a lean condition.
Air Induction System--Air leaks into the induction system which bypass the MAF sensor will cause a lean condition. Inspect for disconnected or damaged vacuum hoses, incorrectly installed or faulty crankcase ventilation valve, or for vacuum leaks at the throttle body, EGR valve, and intake manifold mounting surfaces.
Fuel Pressure--Perform a fuel system pressure test. A faulty fuel pump, plugged filter, or faulty fuel system pressure regulator will contribute to a lean condition.
Injectors--Perform injector coil/balance test to locate faulty injectors contributing to a lean or flooding condition. In addition to the above test, inspect the condition of the injector O-rings.
EGR--Inspect for leaking valve, adapter, or feed pipes which will contribute to a lean condition or excessive EGR flow.
Water contamination in the fuel system can cause a single cylinder to misfire as well as cause a random misfire, refer to Alcohol/Contaminants-in-Fuel Diagnosis .
Many situations may lead to an intermittent condition. Perform each inspection or test as directed.


Important:
Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.


Loose terminal connection
Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.
Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Refer to Testing for Intermittent and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.
Damaged harness--Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.
Inspect the powertrain control module (PCM) and the engine grounds for clean and secure connections. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.
If the condition is determined to be intermittent, reviewing the Snapshot or Freeze Frame/Failure Records may be useful in determining when the DTC or condition was identified.

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

A malfunctioning injector circuit, crankshaft position system variation not learned condition, or incorrect rough road data from the EBCM may cause a misfire DTC to be set. If any of the indicated DTCs are set with DTC P0300, diagnose and repair the other DTC before using the DTC P0300 table.

The Misfire Current Cylinder number display may normally display a small amount of activity (0 - 10 counts) but should not steadily increment during an entire 200 revolution test sample period.

Depending on the cause of the misfire, the Misfire History Cylinder number counter will display a very large number for the misfiring cylinders; values for the non-misfiring cylinders will be less than 1/2 as great as the misfiring cylinders. When investigating a misfire, always start with items associated with the cylinders that has the largest number of counts stored in the Misfire History Cylinder number counter.

If the misfiring cylinders are companion cylinders, the condition is most likely linked to the ignition system.

Inspect for faulty terminal connection, grooves, corrosion, pitting, loose fit.

Inspect for the following conditions that may contribute to the engine misfire: Engine oil pressure, Damaged accessory drive belt or pulley, Damaged driven accessory (generator, water pump, drive belt tensioner), Loose or broken motor mounts.

Gizm0815
04-02-2007, 05:29 PM
all this apears to be a leak comiing from the bottom bolt on the tb not beign tight enough against the gasket. i think i got it fixed

gectek
04-02-2007, 05:46 PM
im a freakin genius...thank you. is it still misfiring?

Gizm0815
04-02-2007, 06:59 PM
problems solved was the bottom tb bolt not tight enough. cars runing great now.

gectek
04-02-2007, 07:44 PM
you know how i knew that....cuz the exact same thing happened to me. and i knew it would happen to someone else. trust me, if it can happen to a GA, i have done almost all of it.

jryland
04-06-2007, 07:40 PM
I just did a LIM gasket and have a couple of questions:
1. Why is the LIM stamped with the even no cylinders at the rear of the engine compartment and the odd ones to the front? This is the complete opposite of what the Hynes manual says. This has led to some confusion in putting new spark plug wires on.

2. When I start the engine up after changing the LIM gasket the engine is now tapping very loudly/badly from the under the valve covers. We stripped it back down again and checked the rockers and reajusted them but it still makes the tapping noise. Any ideas? Manual says it could be the lifters but I never touched them.

gectek
04-06-2007, 10:53 PM
they are stamped like that because it is a cross flow intake, just look at the runners, it should be a dead giveaway. could be the lifters lost their hyd pressure, i would have relubed them at least, but if it is comming from the valve covers, then it may be interference with something, or maybe you dont have the pedestals in the right spots on the head. could be alot of things, just have to narrow them down one at a time

jryland
04-07-2007, 08:57 AM
If I let it idle long enough will the lifters fill up with oil again and regain their pressure?

I am sure this is a very stupid question but I need to ask it, does number 1 on the ignition module go to no 1 cyclinder and no 2 to no 2 and so on?

Thanks

gectek
04-07-2007, 09:57 AM
yes, but no 1 isnt on the ignition module, those numbers are on the coils that are on the module, but yes they correspond to each numbered cyl.

and no the lifters wont regain full pressure, because due to lack of pressure they may have galded themselves in the bore, or a few other internals could be galded and that is why it is ticking. use a stethescope to check everywhere to find out where the problem is really comming from. or better to say they will regain the pressure, but the damage has been done