Fuel issues
Check the fuel pressure, especially if it is hard to start after it has been run for awhile. Also check the ground using an ohm meter, stick it to the pump ground and then the frame, there should be almost no resistance. Or you can check the voltage of the battery with the key turned on, then check the voltage at the pump during its 2 second pre-start pump. The voltages should be within 0.1 volt.
Harry- fix your problem yet? Gallon of water to cool the VCM is good advice, but you can do one better...
It's possible to confirm if the computer is the problem when the fuel pump won't run by jumping 12v to pin1 on C4 of the VCM (black plug(I think); it's the top-driver side plug and a green/white-stripe wire). This is the lead that controls the relay, so the pump will kick on when you apply 12v (I think you can do this with ignition off???). If the relay sticks on for some reason, tap it with a hammer to get it un-stuck (I'm not sure if these relays require negative voltage to separate the internal contacts...). Be aware, you may need to use a thin piece of wire because typical test leads won't go into the VCM plug far enough to contact the female pin socket...
If the VCM doesn't put out 12v on this pin when it's overheated, but you can turn on the pump by jumping the relay, you need a new computer.
This post has the pin listings:
http://www.justanswer.com/questions/...fi-the-in-tank
I learned about this pin while fixing my cruise control yesterday. My module was sending the VCM 5v instead of the requisite 7v; cruise didn't work. A cruise module from junkyard fixed the problem).
Download the PDF (has the same pinout info somewhere..).
http://www.scribd.com/doc/12986652/1...-Repair-Manual
It's possible to confirm if the computer is the problem when the fuel pump won't run by jumping 12v to pin1 on C4 of the VCM (black plug(I think); it's the top-driver side plug and a green/white-stripe wire). This is the lead that controls the relay, so the pump will kick on when you apply 12v (I think you can do this with ignition off???). If the relay sticks on for some reason, tap it with a hammer to get it un-stuck (I'm not sure if these relays require negative voltage to separate the internal contacts...). Be aware, you may need to use a thin piece of wire because typical test leads won't go into the VCM plug far enough to contact the female pin socket...
If the VCM doesn't put out 12v on this pin when it's overheated, but you can turn on the pump by jumping the relay, you need a new computer.
This post has the pin listings:
http://www.justanswer.com/questions/...fi-the-in-tank
I learned about this pin while fixing my cruise control yesterday. My module was sending the VCM 5v instead of the requisite 7v; cruise didn't work. A cruise module from junkyard fixed the problem).
Download the PDF (has the same pinout info somewhere..).
http://www.scribd.com/doc/12986652/1...-Repair-Manual
Last edited by helo; Jul 29, 2010 at 07:31 PM. Reason: oh yeah, test lead didn't work. Had to use a small piece of wire =).
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