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I will try to keep this short. I have a 2008 Suzuki DF90, and have read most of the posts on this site about DF90 mechanical issues. The amount of information available is a bit difficult to digest, so please accept my apologies if my questions have already been covered and thanks in advance for the guidance.
About two weeks ago, I began getting the 4 - 2 diagnostic code and the engine would not start. It would pop but only run for a few seconds before dying. I then noticed that the high pressure fuel pump was not coming on at the moment the key was turned, or at any other time for that matter. I pulled the connector off of the fuel pump and with a handheld volt meter confirmed that power was being sent to it for a few seconds after the key was turned. At that point, I suspected that my fuel had gone bad and wrecked the high pressure fuel pump. However, before tearing into the fuel system, I decided to consult the internet about the diagnostic code. I learned through this and other forums that 4 - 2 points to the crankshaft position sensor (CKP). As best as I can figure the CKP is the little magnetic pick-up that sits just under the flywheel on the front of the motor. I pulled it and it looks brand new. I know that looking new doesn’t mean that it isn’t broken, but before I drop approximately $100 on a new one, I would like to ask if I have eliminated all possibilities.
Will a bad CKP sensor prevent the fuel pump from starting and pressurizing the system? Or will a non-functioning fuel pump cause the ECM to give a diagnostic code as a general warning that something is wrong, without necessarily pointing to the component being coded? Should I take the time to pull the high pressure fuel pump, connect it directly to voltage and see if it works before replacing the CKP? Or should I start by replacing the CKP and move on only if it fails to resolve the problem?
About two weeks ago, I began getting the 4 - 2 diagnostic code and the engine would not start. It would pop but only run for a few seconds before dying. I then noticed that the high pressure fuel pump was not coming on at the moment the key was turned, or at any other time for that matter. I pulled the connector off of the fuel pump and with a handheld volt meter confirmed that power was being sent to it for a few seconds after the key was turned. At that point, I suspected that my fuel had gone bad and wrecked the high pressure fuel pump. However, before tearing into the fuel system, I decided to consult the internet about the diagnostic code. I learned through this and other forums that 4 - 2 points to the crankshaft position sensor (CKP). As best as I can figure the CKP is the little magnetic pick-up that sits just under the flywheel on the front of the motor. I pulled it and it looks brand new. I know that looking new doesn’t mean that it isn’t broken, but before I drop approximately $100 on a new one, I would like to ask if I have eliminated all possibilities.
Will a bad CKP sensor prevent the fuel pump from starting and pressurizing the system? Or will a non-functioning fuel pump cause the ECM to give a diagnostic code as a general warning that something is wrong, without necessarily pointing to the component being coded? Should I take the time to pull the high pressure fuel pump, connect it directly to voltage and see if it works before replacing the CKP? Or should I start by replacing the CKP and move on only if it fails to resolve the problem?
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