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| Floating Idle Problems; Two videos inside, bad idle, poor gas mileage | |
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| Tweet Topic Started: May 4 2011, 10:03 PM (1,413 Views) | |
| mostcallmerob | May 4 2011, 10:03 PM Post #1 |
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Backyard Mechanic
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Hello All, I finally took some videos of what I'm calling a floating or "hanging" idle. After giving the car gas the RPM's will drop but then hang at around 1500RPM then fall to about 900RPM a few seconds later. Not only is this annoying between shifts and at stops but my gas mileage has been horrible. It's a 4/5 but I've been averaging around 30MPG and that's majority highway, I was getting much better gas mileage previously. Lately I've replaced the spark plugs, spark plug wires, distributor cap, rotor, air filter, cleaned the EGR & throttle body, and did an oil change. I've been experiencing it before all that was changed but I'd like to get to the bottom of it to get my gas mileage and normal idle back. 1996 Geo Metro LSi 1.3L 5-Speed 84,0xx miles Any insight or comments on this would be awesome. The videos are below: Video 1: http://www.youtube.com/watch?v=SDdWY43GzzE Video 2: http://www.youtube.com/watch?v=HFV33Wq36cU Edited by mostcallmerob, May 4 2011, 10:04 PM.
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| Deleted User | May 4 2011, 10:55 PM Post #2 |
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Deleted User
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Rob, Check for vacuum leaks. Also check the hose routing in the EGR valve area. I spaced off reinstalling a hose on my EGR valve, and mileage went to crap. Service Engine Soon light on? Any pending codes? |
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| mostcallmerob | May 4 2011, 11:04 PM Post #3 |
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Backyard Mechanic
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I haven't gotten it scanned yet but the SES light is not lit up. I'll try to get a vide of what the engine sounds like from the engine bay, it may give you a better idea of what it may be but a vacuum leak sounds probable.
Edited by mostcallmerob, May 4 2011, 11:04 PM.
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| Bad Bent | May 5 2011, 07:04 PM Post #4 |
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Facetious Educated Donkey
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Seems like a classic vacuum leak. The other things to check are the PCV valve which if stuck open is a vacuum leak. What was done to the car before the surging started? Checking the hoses is a good idea. You may just want to replace them so you know they are good and the routing is correct. To start buy 5' of hose and replace one at a time. Clean your grounds and especially the one on the TB above the alternator. |
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| chubart | May 5 2011, 07:12 PM Post #5 |
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This may help? |
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| Johnny Mullet | May 5 2011, 08:34 PM Post #6 |
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Fear the Mullet
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Normal. |
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| mostcallmerob | May 6 2011, 04:52 PM Post #7 |
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Backyard Mechanic
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The way it's acting it seems like a vacuum leak, I might go around and start blasting the vacuum hoses with carb cleaner and listen for changes in engine speed or pitch. Johnny, I wouldn't care if this potentially didn't affect my gas mileage but the Geo has been getting horrible mileage lately and with gas on the rise I'd like to get to the bottom of this. |
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