Rough idle after hot start.
04-09-02, 05:43 PM
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Rough idle after hot start.
Before any of you ask me to "search", I've used the words "hot", "idle", "rough", "start", and "lumpy" in various combinations and still I can not find any leads, much less answers, okay? If you know what words I SHOULD be using, then please, by all means, post those words and I will search it myself.
Anyway...
Whenever I start up the car while hot (after refueling, in-and-out shopping, errands, etc) My RX-7 idles rough (fluctuating maybe 600 to 900rpm) for just a few seconds until I give it some gas, or start moving. Starting up the engine is fine--no extended cranking needed, and no smoke or odd smells.
Any ideas on what is causing this? Heat soak? Temperature? Voltage? Fuel Pressure? Spark plugs?
Cold starts in the morning or after letting the car sit a few hours or more are just fine. No rough idle. No smoking. No extended cranking to start. It's the hot starting just minutes after shutting off that I'm interested in finding out. Thanks in advance.
Anyway...
Whenever I start up the car while hot (after refueling, in-and-out shopping, errands, etc) My RX-7 idles rough (fluctuating maybe 600 to 900rpm) for just a few seconds until I give it some gas, or start moving. Starting up the engine is fine--no extended cranking needed, and no smoke or odd smells.
Any ideas on what is causing this? Heat soak? Temperature? Voltage? Fuel Pressure? Spark plugs?
Cold starts in the morning or after letting the car sit a few hours or more are just fine. No rough idle. No smoking. No extended cranking to start. It's the hot starting just minutes after shutting off that I'm interested in finding out. Thanks in advance.
04-10-02, 07:46 AM
#2
HEY EVEL333
THE PROBLEM SOUNDS LIKE HEAT SOAK TO ME & YOUR AIR TEMP SENSOR IS MORE THAN LIKELY THE CULPRIT.ON SOME AFTERMARKET COMPUTERS TOU CAN TUNE THIS PROBLEM OUT BY ADDING FUEL AT THE PROBLEM AREA WITH THE AIR TEMP COMPENSATION.I'M NOT TOO SURE HOW THE POWER FC WORKS BUT I IMAGINE IT WILL BE SIMILAR.I USE MOSTLY MICROTECHS AND FIX THE PROBLEM DOING IT LIKE THAT.
ANOTHER TIP IS TO REMOVE THE AIR TEMP SENSOR FROM IT'S FACTORY LOCATION & MOUNT IT IN THE PLASTIC INTAKE PIPE BEFORE THE THROTTLE BODY.THIS GETS IT WELL AWAY FROM THE HEAT & THE COMPUTER ISN'T AS PRONE TO SUFFERING THE PROBLEM.
GOOD LUCK
THE PROBLEM SOUNDS LIKE HEAT SOAK TO ME & YOUR AIR TEMP SENSOR IS MORE THAN LIKELY THE CULPRIT.ON SOME AFTERMARKET COMPUTERS TOU CAN TUNE THIS PROBLEM OUT BY ADDING FUEL AT THE PROBLEM AREA WITH THE AIR TEMP COMPENSATION.I'M NOT TOO SURE HOW THE POWER FC WORKS BUT I IMAGINE IT WILL BE SIMILAR.I USE MOSTLY MICROTECHS AND FIX THE PROBLEM DOING IT LIKE THAT.
ANOTHER TIP IS TO REMOVE THE AIR TEMP SENSOR FROM IT'S FACTORY LOCATION & MOUNT IT IN THE PLASTIC INTAKE PIPE BEFORE THE THROTTLE BODY.THIS GETS IT WELL AWAY FROM THE HEAT & THE COMPUTER ISN'T AS PRONE TO SUFFERING THE PROBLEM.
GOOD LUCK
05-03-19, 01:07 AM
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Did this fix your problem? Mine started having this problem too. When ever I go to class and let it sit for a few hours it starts fine but if I go to a store or something for like 30 minutes when I start it back up the idle keeps dropping and returning to 900 and almost stalls sometimes then is perfectly fine after it warms up. I couldn't find any other threads about this either.
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