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Low RPM Hesitation and Rough Idle

 
Old 11-21-2018, 02:32 PM
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Default Low RPM Hesitation and Rough Idle

Car battery died a few days ago and have had to jump start it the past 2 days. Replaced the battery with no issues at startup. Drove the car about an hour to suddenly have a hesitation around 2K RPM under medium load. First thought was the fuel pump went out as it has not held pressure when the ignition is off for about a year. Tested the fuel pressure today and at idle was 58 PSI and holds through the entire RPM range. Disconnected MAF senor with same hesitation. The odd thing is that the car runs fine until the hesitation begins at which point the idle becomes rough as well. LTFTs spike during the hesitation and rough idle; + 12-14 on each side. Car appears to be running incredibly rich as it reaks of gas and visible dripping of gas from the exhaust. If I turn the car off for a few mins the issue goes away until I put a heavy load on the motor while in gear, does not have issues at idle in park. MAP reads a typical vacuum of 16" and 10" during rough idle. Any thoughts on what it could be?
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Old 11-22-2018, 11:47 AM
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Not a stock computer guy, but nothing can go closed loop until the O2 sensor heats up. How long does it take to start running wrong? O2's I've used a lot fail and read lean.
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Old 11-24-2018, 08:20 PM
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Changed the O2 sensors, plugs, and wires. Still having the hesitation around 2000 RPM with spiking fuel trims followed by rough idle. Could the PCM have been shorted out? Any other thoughts?
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Old 11-24-2018, 08:23 PM
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You still did not answer Crf450r420's question. How long does it take to start running wrong?
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Old 11-24-2018, 09:07 PM
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Sorry forgot to mention. Regardless if the car is warm or cold it will do the same thing. It will idle fine for a long time, but as soon as it gets under load the engine shuddering begins. Leave it off for a few mins and it idles fine again.
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Old 11-26-2018, 09:49 AM
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So, by load you mean? Explain what you can do to get a repeat?
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