Filed Under (Isuzu) by admin on 13-11-2010
high/erratic idle and/or the MIL light on. In some cases, vacuum leak noise may be heard as well. There may be poor contact or loss of contact at various main ground points or electrical connections. Power steering pressure switch may be shorted with debris. Inlet manifold gasket may be leaking. Broadcast code and calibration part number may need to be updated. To correct this condition, follow the procedures outlined in this bulletin to determine proper diagnosing, inspection and correction of ground contact points for proper electrical contact, power steering pressure switch cleaning or replacement and power steering system flush, replacement of inlet manifold gasket, and/or PCM reprogramming. SERVICE PROCEDURE Please refer to the appropriate workshop manual for the correct diagnosing procedure and/or follow the service procedures outlined in this bulletin for the vehicle being serviced. 1. Inspect main ground points (refer to SB99-04-S001 for more information). P6 ground point-body [on the passenger side of engine compartment, between the battery and cruise control actuator (if equipped)]. (Figure Fig. 1 ) P10 ground point-engine (at the alternator bracket). (Figure Fig. 2 ) The 1998, 1999 or 2000 Rodeo/Amigo Electrical Troubleshooting Manual can assist in locating the vehicle ground distribution (i.e., ground contact points). Perform a voltage drop test at the main ground points. If the voltage drop test fails, then inspect and clean both the bolt and
Filed Under (Dodge) by admin on 31-10-2010
The high-speed idle screw is factory sealed and cannot be adjusted. Low-speed idle can be adjusted. 1. Use an optical tachometer such as Snap-on No. MT139 or MTE (Cummins tool division) No. 3377462 to read the engine RPM. 2. Bring the engine to normal operating temperature. 3. Adjust the low idle speed at the low idle speed screw. The screw and locknut are located at the rear of the fuel injection pump. 4. Loosen the idle screw lock nut. Adjust idle screw to obtain specified RPM. LOW IDLE SPEED With automatic transmission: 750-800 RPM with transmission in drive and air conditioning on. With manual transmission: * 780 RPM with transmission in neutral and air conditioning on. * With engine at operating temperature. HIGH IDLE SPEED Do not attempt to adjust high idle speed. High idle speed adjustment screw is factory sealed. Breaking seal will void injection pump warranty 5. Tighten the locknut after adjustment.
Filed Under (Oldsmobile) by admin on 17-01-2011
Models: 2004-2005 Buick Rainier 2002-2005 Chevrolet TrailBlazer Models 2002-2005 GMC Envoy Models 2002-2004 Oldsmobile Bravada 2005 Saab 9-7X Condition Some customers may comment on slow to cool Air Conditioning (A/C) performance or high A/C outlet temperatures after start up or that the A/C system is not cooling sufficiently, especially in high ambient temperatures. This may be an intermittent condition and the performance of the Heating, Ventilation and Air Conditioning (HVAC) system may not meet customer expectations. Cause This condition may be caused by the response of the Electro-Viscous (EV) fan clutch and can be related to airflow across the condenser. This low A/C system performance can occur for longer periods of time if the vehicle is allowed to idle or is driven in low speed conditions. The response of the EV fan clutch will affect A/C system performance. As higher road speeds are attained, the increased airflow across the condenser will usually improve A/C system performance and the response of the EV fan clutch. This condition may be more evident after the vehicle has set for a period of time and can be difficult to duplicate. The condition may occur after the vehicle has set for as little as 10 minutes or as long as overnight. It is most prevalent intermittently during the first 15 minutes of operation.
Filed Under (Chrysler) by admin on 12-11-2010
OVERVIEW: This bulletin involves rotating all engine exhaust valves, replacing the valve spring retainer locks with a new design to increase valve rotation at lower RPM, inspecting/replacing the MAP sensor (as necessary), and decarbonizing the combustion chamber. MODELS: 2004 – 2006 2005 – 2006 (CS) (LX) Pacifica Chrysler 300/Magnum/Charger SYMPTOM/CONDITION: The customer may experience occasional engine misfire (rough running engine) during certain vehicle operating conditions. In addition, MIL illumination may also have occurred due to Diagnostic Trouble Code (DTC) P0300 – Multiple Cylinder Misfire. Various single cylinder misfire DTC’s may also be present. If the frequency of misfire is high, the Powertrain Control Module (PCM) may place the engine in “Limp-In” mode. The misfire condition may be caused by one or more engine exhaust valves that are slow to close due to a build up of carbon on the valve stem. DIAGNOSIS: 1. This condition may occur when the engine is not allowed to run at engine RPM’s that are greater than 3,500 RPM. At 5,000 RPM or higher the engine exhaust valves will rotate if not impeded by high carbon deposits. Low engine RPM’s and high carbon deposits are associated with short trip driving where the engine is not allowed to fully warm to normal engine operating temperatures. Cold ambient temperatures will increase engine warm-up time and increase the likelihood of carbon deposit build-up on the stem of the engine exhaust valve. Fuel detergent quality may also contribute to the condition; the customer may want to try a different brand of fuel. 2. Verify that the engine misfire condition is not caused by faulty engine mechanical or electrical components. 3. If the engine mechanical and electrical systems are operating properly perform the Repair Procedure.
Filed Under (Nissan) by admin on 21-12-2010
Customer Concern: Tests/Procedures: Potential Causes: Tech Tips: Just did a tune up and cleaned the throttle body and now the idle is hunting up and down. 1. Perform the Accelerator Pedal Released Position Learning procedure. 2. Perform the Throttle Valve Closed Position Learning procedure. 3. Perform the Idle Air Volume Learning procedure described in the Identifix article listed for this vehicle. It may be necessary to follow TSB# NTB05-067 and disconnect one or more fuel injectors as necessary to bring the RPM down and then perform the Idle Air Volume Learning procedure. 4. If the idle will not relearn, it may be necessary to bring the vehicle to the dealer to have the factory scan tool, try going through the relearn procedures. 5. If the problem still occurs, the vehicle may require throttle body replacement. Idle Relearn Procedure Engine speed at 200 RPM or more over the target idle speed will set this code. There is a TSB (TSB# NTB05-067) concerning this code that refers to disconnecting one or more fuel injectors to bring the RPM down and perform the Idle Air Volume Learning procedure. It often takes disconnecting two injectors to bring the engine RPM low enough for the idle relearn to work. The idle will not relearn if the engine speed is too high. During the relearn procedure, idle relearning actually begins when the engine is started. The TSB refers to using the factory Consult scan tool, but the manual procedure does work if the procedure is followed EXACTLY. The engine and automatic transmission (if equipped) needs to be warmed up too – follow the preparation instructions.