I have a 92 Volvo 940 GL 4D Sudan with good mileage, but recently whenever I press the gas there's a bogging down feeling and a delay in the 'get up and go'.. After about 3 seconds its fine, but when I let off the gas while driving to speed it does the same thing. My speedometer also just went out... Ugg... can anyone help?
My 92 940 Gl Is Bogging Down When I Press The Gas?
Started by ChristopherMitchell, Sep 20 2009 04:21 PM
2 replies to this topic
#2
Three Fat Tigers
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Posted 21 September 2009 - 12:13 AM
I'd start by checking for any stored ODB1 codes:
http://www.brickboar...ineOBDCodes.htm
The speedometer provides an speed input to the fuel computer, so there is a possibility that might be related. I would first inspect the electrical connector at the differential cover, check for wiring harness failure right at the connector. Next pull the instrument panel to access the speedometer connector, unplug and measure between the two speed sensor wires, don't know the colors, but they are the two wires that are twisted together. IINM, they should read somewhere between 600 and 1600 ohms. If that looks good, you may have a fault in the speedo, or a failure somewhere in the printed circuit film on the back of the instrument cluster.
Next I would test the fuel pressure, and also make sure the main pump under the car is not making a lot of noise. If the problem is less/gone when the tank is full versus half to less than half full, you may have an in-tank pump failure, or a failure in the hose between this pump and the sending unit.
If your car has the Regina fuel system (large square ignition coil mounted on the front of the left strut tower), check the vacuum line running to the MAP sensor, located behind the left strut tower. Should have good vacuum, replace the line if there is any question.
If your car has Bosch LH2.4 (small ignition coil behind the right strut tower), you may have a bad MAF sensor, try another one, and also inspect the air box thermostat (if so equipped) and make sure the preheated air supply is closed off at temps above 59ºF, as otherwise the heated air will tend to cook (damage) the MAF sensor.
From my personal experience, bogging on inclines or from a stop indicate a fault in the MAF sensor.
http://www.brickboar...ineOBDCodes.htm
The speedometer provides an speed input to the fuel computer, so there is a possibility that might be related. I would first inspect the electrical connector at the differential cover, check for wiring harness failure right at the connector. Next pull the instrument panel to access the speedometer connector, unplug and measure between the two speed sensor wires, don't know the colors, but they are the two wires that are twisted together. IINM, they should read somewhere between 600 and 1600 ohms. If that looks good, you may have a fault in the speedo, or a failure somewhere in the printed circuit film on the back of the instrument cluster.
Next I would test the fuel pressure, and also make sure the main pump under the car is not making a lot of noise. If the problem is less/gone when the tank is full versus half to less than half full, you may have an in-tank pump failure, or a failure in the hose between this pump and the sending unit.
If your car has the Regina fuel system (large square ignition coil mounted on the front of the left strut tower), check the vacuum line running to the MAP sensor, located behind the left strut tower. Should have good vacuum, replace the line if there is any question.
If your car has Bosch LH2.4 (small ignition coil behind the right strut tower), you may have a bad MAF sensor, try another one, and also inspect the air box thermostat (if so equipped) and make sure the preheated air supply is closed off at temps above 59ºF, as otherwise the heated air will tend to cook (damage) the MAF sensor.
From my personal experience, bogging on inclines or from a stop indicate a fault in the MAF sensor.
#3
ChristopherMitchell
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Posted 21 September 2009 - 03:24 AM
I'd start by checking for any stored ODB1 codes:
http://www.brickboard.com/FAQ/700-900/EngineOBDCodes.htm
The speedometer provides an speed input to the fuel computer, so there is a possibility that might be related. I would first inspect the electrical connector at the differential cover, check for wiring harness failure right at the connector. Next pull the instrument panel to access the speedometer connector, unplug and measure between the two speed sensor wires, don't know the colors, but they are the two wires that are twisted together. IINM, they should read somewhere between 600 and 1600 ohms. If that looks good, you may have a fault in the speedo, or a failure somewhere in the printed circuit film on the back of the instrument cluster.
Next I would test the fuel pressure, and also make sure the main pump under the car is not making a lot of noise. If the problem is less/gone when the tank is full versus half to less than half full, you may have an in-tank pump failure, or a failure in the hose between this pump and the sending unit.
If your car has the Regina fuel system (large square ignition coil mounted on the front of the left strut tower), check the vacuum line running to the MAP sensor, located behind the left strut tower. Should have good vacuum, replace the line if there is any question.
If your car has Bosch LH2.4 (small ignition coil behind the right strut tower), you may have a bad MAF sensor, try another one, and also inspect the air box thermostat (if so equipped) and make sure the preheated air supply is closed off at temps above 59ºF, as otherwise the heated air will tend to cook (damage) the MAF sensor.
From my personal experience, bogging on inclines or from a stop indicate a fault in the MAF sensor.
