I have a 1995 Holden Apollo and I have just had an engine mount fixed, map sensor replaced, spark plugs replaced and new welsh plugs also we tried to reset the idle however don't think that has worked. Now when I start the car in the morning it vibrates a lot and when I try to accelerate it holds back, it won't accelerate until I rev it a bit. Also when I stop at the lights it vibrates so much I feel like the engine will fall out. Someone said about checking the transmission and fuel filter to see if it is clogged up but I believe the idle needs to be reset. However diagnostic testing did not show a problem with the idle. Someone also said about the timing on the timing belt but I don't believe that is the problem what do you think?

Start w ECM scan, address codes, Check for any cam or crank sensors codes. Check fuel PSI, are the injectors firing? Plug sparking? I know there new but are they working? Scan 1st take it from there. Many emissions sensors (MAF etc can have same effect.) start w scanning

check replace faulty engine mounts

Try buying a manual.
http://onlyrepairmanuals.com/holden/holden-commodore-vt-vx-vy-vu/
Using the manual above wWhen I did my welsh plugs last year it was easy as. I got it free.. i think it's paid for now.

More likely the MAP sensor. A new sensor is $65, so I recommend you test it to see if it's bad. Test procedures are pasted below. Please let me know if it passes the tests or if you have any questions, and thanks for using FixYa.

OPERATIONThe PCM supplies 5 volts to the Manifold Absolute Pressure (MAP) sensor. The MAP sensor converts what it reads as the amount of intake manifold pressure into a return signal. The PCM monitors the MAP sensor output voltage. As vacuum increases in the intake manifold, the MAP sensor voltage decreases proportionately. Also, as vacuum decreases, the MAP sensor voltage increases proportionately.
During engine cranking, before the engine starts running, the PCM determines atmospheric air pressure from the MAP sensor voltage. While the engine operates, the PCM determines the intake manifold pressure from the MAP sensor voltage.
Based on MAP sensor voltage and inputs from other sensors, the PCM adjusts spark advance and the air/fuel mixture.
TESTING

Fig. Fig. 1: Manifold absolute pressure (MAP) sensor wiring schematic-1993-95 models

Fig. Fig. 2: Manifold absolute pressure (MAP) sensor connector terminal pin locations-1993-95 models


Before testing any electrical component, inspect the wiring and connectors for damage. Also wiggle the connectors to ensure a that they are firmly engaged. When testing the sensor, use a high input impedance digital volt-ohmmeter. Insert the tester leads through the back of the connector. Do not disconnect the electrical harness.

1. Inspect the vacuum hose connections at the sensor and throttle body. Repair or replace the hoses, if any hoses are cracking or vacuum is leaking.

For the following step, do not unplug the sensor connector-it must stay plugged in.

1. Make sure that the sensor wiring connector is fully inserted into the sensor (loose connections can create trouble codes). Check the MAP sensor output voltage by inserting the negative lead of a voltmeter into the back of terminal 2 and the positive test leads through the back of the harness connector terminal 3 (as marked on the sensor body). Refer to the accompanying wiring illustration. With the ignition switch in the ON position and the engine OFF , the output voltage should be 4-5 volts.
2. Start the engine and allow to idle at normal operating temperature. The output voltage should drop to 1.5-2.1 volts.
3. Test the PCM terminal 36 (1993-95 models), and terminal 1 (1996-97 models) for the same voltage described above to verify the wire harness condition. Repair the wiring harness if the voltage is not the same.
4. Test the MAP sensor supply voltage at the sensor connection terminal 2 and 1 with the ignition ON . The voltage should be 5 volts. Check the supply voltage at terminal 61 of the PCM. This should also be 5 volts.
5. Using an ohmmeter, test the MAP sensor ground circuit at the sensor connection terminal 1 and at the PCM terminal 43 (1993-95 models), terminal 4 (1996-97 models). Repair the wire harness for an open circuit if infinite resistance is detected.

REMOVAL & INSTALLATION

Fig. Fig. 6: On the 3.5L engine, the MAP sensor is threaded into the left side of the intake manifold plenum

The MAP sensor is located in the rear of the intake manifold plenum on the 3.3L engine. On the 3.5L engine, the MAP sensor is threaded into the left side of the intake manifold plenum.

1. Disconnect the negative battery cable.
2. Unplug the electrical connector from the sensor.
3. Remove the MAP sensor mounting screws.
4. Remove the sensor from the vehicle.

To install:

1. Install the MAP sensor into its position and secure in place with the mounting screws. Tighten the screws to 90 inch lbs. (10 Nm), then rotate it to a horizontal position.
2. Plug the electrical connector back into the sensor. Make certain that the connector is clean and snug fitting.
3. Connect the negative battery cable.

Many times this issue can be caused by a dirty air filter, I would start there if you already
haven't done so.

Also, if you haven't recently changed your spark plugs and wires you may consider pulling
out atleast one spark plug to look at its condition.

• • • The sensor is mounted in a fixed position in the engine block. The tip of the sensor protrudes into the crankcase at a distance of 0.05 plus or minus 0.02 inch from the crankshaft.
    • A crankshaft adjusting tool may be used to check these rings
    place the tool on the pulley extension surface and rotate the tool around the pulley.
  • If any blade touches the tool, replace the pulley.
• Inspect the trigger wheel behind the crankshaft pulley and the sensor for damage.
• If the engine misfires all the time or on acceleration only, test the following components:
  • Engine compression.
  • Spark plugs.
  • Spark plug wires.
  • Ignition coils test for firing voltage with a test spark plug.
  • Crankshaft sensor.
  • Fuel injectors on multiport and sequential fuel injection systems. To remove the crank sensor

• Disconnect the wiring harness.
• Unbolt the sensor mounting bolt.

If the crankshaft timing sensor or the camshaft reference sensor is removed, follow this procedure when the sensor is replaced:

• Thoroughly clean the sensor tip and install a new spacer on the sensor tip. New sensors should be supplied with the spacer installed.

Spacer on crankshaft timing sensor and camshaft position sensor.

• Install the sensor until the spacer lightly touches the sensor ring, and tighten the sensor mounting bolt 105 in.lb.

hope this was what you needed.....

No all a map sensor measures the pressure in the mainfold. But if you have a code for a map sensor i would suggest replacing it. Check your spark plugs cap and rotor.

Disconnect the spark plug wires by pulling them upward firmly. Use a spark plug socket (5/8 in.) to loosen the spark plugs down in the tube. Pull them out with needle nose plier or a magnet if necessary. When replacing take care not to cross-thread.

oh I'm not an expert on this car but if you have platinum plugs or similar plugs in it that means they don't need to be changed as often due to the fact that it is a big job.Most cars nowadays are set up in such a way that you have to take off the whole air induction setup just to get to them.My advice if this is the case is to get someone else to do it.

you were sold a lemon

1. check for proper fuel pressure 49 psi
2. check for spark
3. if no spark check the crankshaft position sensors. there are two crank position sensors on the aurora.