Knivens894
Well-Known Member
I want to pick your mind with a problem I am having with the 490E. It is repeatedly causing the failure of both the PD sensor and the angle sensor. The last ones worked for about a week, then went south. I have been using after market units made in China. When I last replaced both units (adjusted to specs) and one HP pump solenoid (which had a melt down), about a month ago, the machine performed beautifully and the heat problem I was having went away. For the first time ever, the stalling problem I was having went away, then about a week later, it went back to the jerky and stalling mode. When I tried to reset the DP sensor yesterday, it read 1.05V and would not take adjustments. I checked the angle sensor, and it also read 1.03 V and would not take adjustments. I have been through about 6 each of angle sensors and DP sensors since I have owned this machine.
My findings and theory of the last failure was based upon a fault at the DP sensor found upon removal. When I moved the unit in my hand, the voltage reading changed. There was a bad connection within the DP unit itself. A solder connection in the unit was making and breaking which I confirmed by cutting it apart. My theory was that the poor connection had caused the HP solenoid to go full open, resulting in the over heating of the HP solenoid. My question is why would it also fail the angle sensor? Something is amiss in that system. What could possibly be the cause of the failure of both units at the same time?
My first thought is a fault in the wiring harness. Today I plan the disconnect the computers and meg test the harnesses to look for a fault. Do you have any other ideas or suggestions?
Another question I have is there was a small plastic tube running from the high pressure side of the intake manifold. It broke off at the fitting and I cannot determine where it went. Do you know where it should terminate and what its purpose was? Could it be associated with the other problem?
Thank you in advance for your consideration and advice on this issue.
My findings and theory of the last failure was based upon a fault at the DP sensor found upon removal. When I moved the unit in my hand, the voltage reading changed. There was a bad connection within the DP unit itself. A solder connection in the unit was making and breaking which I confirmed by cutting it apart. My theory was that the poor connection had caused the HP solenoid to go full open, resulting in the over heating of the HP solenoid. My question is why would it also fail the angle sensor? Something is amiss in that system. What could possibly be the cause of the failure of both units at the same time?
My first thought is a fault in the wiring harness. Today I plan the disconnect the computers and meg test the harnesses to look for a fault. Do you have any other ideas or suggestions?
Another question I have is there was a small plastic tube running from the high pressure side of the intake manifold. It broke off at the fitting and I cannot determine where it went. Do you know where it should terminate and what its purpose was? Could it be associated with the other problem?
Thank you in advance for your consideration and advice on this issue.
