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Discussion Starter #1
I recently drove this car 1000 miles accross the Philippines, but on the way I encountered a strange problem related to the fuel pressure. Under hard acceleration up hill the car started sputtering and running real rough, pulling over to the side of the road it was idling real rough. This was the middle of nowhere, but since I had a spare new fuel filter in the trunk I decided to try and change the filter. Opening the connection on the old filter I noticed the fuel pressure was really high, i changed the filter and the car fired right up again. the old filter was very dirty.
I thought the problem was solve, however next steep uphill and hard acceleration the car started acting up exact same way again. Once again I just released the pressure at the fuel filter and the car fired right up again.
It seems this is fuel pressure related, does anyone has any idea?

btw. I made it the next 500 miles just being soft on the throttle
 

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Discussion Starter #2
I forgot to mention that I just recently did replace the intank fuel pump with an original one. And it was clear from our journey that the fuel pressure fluctuates, as the pump noise goes from real quiet to whining noise and pump cutting in/out when the engine was running real rough (after the hard accelerations).
 

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Could the steepness of the hill divert fuel to another part of the tank thereby starving the pump?
Only troubleshooting tip I have is duct tape a fuel pressure gauge to the windshield with the gauge hooked to the Scrader valve on the fuel rail and go climb a hill and see if the gauge drops off climbing or coming down from the hill.
 

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Discussion Starter #5
Could the steepness of the hill divert fuel to another part of the tank thereby starving the pump?
Only troubleshooting tip I have is duct tape a fuel pressure gauge to the windshield with the gauge hooked to the Scrader valve on the fuel rail and go climb a hill and see if the gauge drops off climbing or coming down from the hill.
Problem not only on hills, during all heavy acceleration, empty tank, half full or full, no difference.
 

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Since it appears all the time, after warm-up, and the problem goes away after relieving the fuel line pressure,
I suggest the next time it happens, opening the filler cap and notice if the tank pressure is relieved by a large amount, If so, then I would look at the charcoal cannister solenoid(s) as they control and relieve the tank pressure by PCM commands.

The fuel pump groans, as you mention, are an indication of the pump working, quiet = no load, heavy noise = working.
 

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Discussion Starter #7
Since it appears all the time, after warm-up, and the problem goes away after relieving the fuel line pressure,
I suggest the next time it happens, opening the filler cap and notice if the tank pressure is relieved by a large amount, If so, then I would look at the charcoal cannister solenoid(s) as they control and relieve the tank pressure by PCM commands.

The fuel pump groans, as you mention, are an indication of the pump working, quiet = no load, heavy noise = working.

hi Everett, thanks, will check tank pressure as well.
I agree with you on the noise level of the pump, pressure goes so high the pump cuts out.
 
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