1988 Mercury Marquis will only run above 1/2 throtle

1988 MERCURY MARQUIS
140,000 MILES • V8 • 2WD • AUTOMATIC
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ROCKY_TOP
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  • 2 POSTS
The car will start and then die unless you rev the engine. after a while it will get closer to running at an idle. I replaced the plugs, wirers, cap, and rotor. I thought that it could be the fuel pump but it runs at highway speeds without stalling. The problem started sudenly and I am not getting a check engine light.
Jan 3, 2010 at 2:47 PM
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RASMATAZ
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Hi rocky_top Welcome to 2carpros and TY for the donation and selecting us as your auto repair site. Feel free to ask questions at anytime

Check and test the idle speed control solenoid, Manifold absolute pressure sensor and throttle position sensor-Also do a fuel pressure check to rule out the fuel pump if its within specs-could be on its way out
Jan 4, 2010 at 11:32 AM
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ROCKY_TOP
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It was the map sensor
Jan 10, 2010 at 2:39 PM
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