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I'm not a car expert so I don't know if I'm being alarmist or not but this problem just started happening the past week and seems to be getting worse fast. Hopefully the terms I'm using is helpful in describing my problem.

So, I have a 2005 Honda Accord LX with automatic transmission and 170k miles. The car has been good to me thus far and I've brought the car in every 10k to the dealership as the manual said.

My car is parked in a garage and I live in California so the temperatures aren't extremely cold in the morning. Normally, when I start my car cold in the morning, the idling RPMs will be about 1500rpm. After about 1-2 min of warming up, it drops to about 800-900 and drive from pt A to pt B.

This problem just started 1 wk ago. What happens is on a cold start, the rpms are unusually low (about 400-500 rpms). I waited a few minutes but the rpms didn't go back up. This has happened 3 times the last 7 days. Luckily, I've been able to drive to my destinations without problems (no knocking, no loss of power these 3 times, no engine dying)

Today, the problem got worse in that the engine didn't have power when I shifted to reverse to back out. Usually, I just shift to reverse and let the automatic transmission back me into the street. Today, there was no movement. Stepping on the gas helped inch the car out of my driveway but there was not much power when gassing it.

Also, the car died twice while stepping on the gas to back it out. I was able to drive to work without incident (no knocking, no loss of power, engine didn't die on the way to work). At first I thought I had a spark plug issue or a cylinder issue but since I was able to drive on the highway without incidents, I'm guessing that's not the case.

I know it's hard to diagnose something w/o seeing or hearing what's happening but does anyone know what might be happening from what I'm describing? I read some other forums and sites and people who had similar problems were advised to check the spark plugs, the idle screw or something with the throttle body, check for vacuum leaks or something, etc.

I don't know if their situation is the same as mine so I don't know if the solutions proposed to them would be the solution for me too. Thanks in advance for any help you can give me.

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I don't have a sure answer for you, but I will tell you do not adjust the idle screw (if you can even get to it), and I doubt it's a vacuum leak because with a vacuum leak, the idle usually goes up (though dies easily when you step on the gas). I'm thinking you might have a problem with the throttle position sensor and/or the air idle control valve, but am not sure. Are there any codes (check engine light on)? –  Paulster2 Apr 1 at 22:38
    
@Paulster2, thx for your reply. No check engine light or anything. No codes showing on the dash and I unfortunately don't have one of those code checking gadgets that you plug into under the steering column. I can ask my friends if anyone has one of those and report any codes that show up back here...assuming my car doesn't get worse. –  Classified Apr 1 at 22:51
    
Just an update, not sure what happened but the problem didn't come back after i posted this. If/when it happens again, I'll update what happens. I'll also update if I can't figure it out and take it to a mechanic to see what they say. –  Classified Apr 7 at 19:17
    
I don't know whether to like or hate when problems go away on their own ... you just never know what the problem actually was. –  Paulster2 Apr 7 at 21:15
    
@Paulster2, i agree. Now I'm afraid one day I'll wake up and the car won't start or move at all. I'd much rather have it keep acting up so I can try to figure it out or have a mechanic see/hear and figure it out. Thx again for your feedback. –  Classified Apr 7 at 22:22

1 Answer 1

This can some times happen after periods where the car is not driven fast or for long periods of time. Engines can build up junk that will be easily cleared after a 10 min drive on the interstate. there is also the possibility of bad fuel however this is not confirmable. I would stick with the fact that there was excess build up of junk from lots of short slow trips. ECU's will adjust the fuel table and settings if the O2 Sensor is fowled. -attempting to fix what is not an issue. Again a quick hop on the interstate will quickly burn off excess carbon buildup on the O2 Sensor.

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