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Rough idle, stalling, falling gas mileage

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Old 02-23-2006, 01:22 PM
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Default Rough idle, stalling, falling gas mileage

My car started to stall occasionally when I would come to a stop of make a slow turn, but only before the car reached normal operating temperature. It has progressed to stalling during operating temps and the idle started to surge at all times. I decided to change the PCV, O2, TPS, MAF, and IAC sensors. I have also changed the fuel filter, plugs & wires, and all three ignition coils and cleaned the trottle body. The problem still is still there and is getting worse. My gas mileage has suffered greatly. I was avg 27mpg and now I avg about 14mpg. The idle is so bad now that the car will barely run in park with out giving it gas.
Other than the high consumption of fuel the car rides fine during driving. I did notice that idle is better if I disconnect the vaccum hose to either the FPR or the vapor canister. I have read many posts on similar problems, but I never found a real solution. Any ideas is appreciated.
Old 02-23-2006, 01:24 PM
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Two things come to mind. Fuel Pressure Regulator and Fuel Pump.

You'll need a fuel pressure gauge to determine which is the problem Pressure is probably low due to worn out fuel pump.
Old 02-23-2006, 01:37 PM
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I'm leaning toward the FPR also, because the fuel pump is less than a year old.
Old 02-23-2006, 01:43 PM
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You should still use that fuel pressure guage to check before you throw more money at it, IMO.
Old 02-23-2006, 01:58 PM
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I agree, test it with the vacuum hose hooked up and then remove it. When the hose is removed it defaults the system to max pressure.
Old 02-23-2006, 03:07 PM
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Is there no codes ?
Old 02-23-2006, 04:49 PM
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The CEL does come on, but goes away when driving. I'm going to have it scanned on monday. Thanks
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