1999 Mercury Cougar Stall on left turn with quarter tank

1999 MERCURY COUGAR
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NUDIJOEL
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Engine Performance problem
1999 Mercury Cougar 6 cyl Two Wheel Drive Automatic

For the past few weeks, when there is a quarter tank of gas or so, the engine stalls while making a left turn. Friendly neighborhood Autozone ran a diagnostic and could find nothing. They claim a bad fuel pump would have shown up on the test. Any ideas?
Mar 6, 2010 at 2:48 PM
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MATHIASO
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Hello nudijoel

Fuel injected engines are very sensitive to fuel pressure as well as fuel volume. Low pressure will cause starting and driveability problems. A pump that can deliver adequate pressure but not enough volume may allow the engine to start and idle normally, but it will starve the engine for fuel and cause a loss of power when the engine is under load. Certain scan tool can show fuel pump pressure but not fuel volume.if fuel volume is good, checks the operation of the fuel pressure regulator to make sure it changes line pressure in response to changes in engine vacuum. This is necessary to maintain the proper operating pressure behind the injectors and to compensate for changes in engine load:
for example turning the steering or making a turn, turning AC on...
Check the charging voltage to start with.
Mar 6, 2010 at 8:23 PM
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