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| 1.0 idle; how to fix | |
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| Tweet Topic Started: Aug 4 2012, 11:51 AM (1,210 Views) | |
| a.r.madillo | Aug 4 2012, 11:51 AM Post #1 |
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Fresh Fish
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Hello. I have a geo metro 1.0 with a 5 speed. Engine starts quickly and high idle is about 1700 rpm. It starts to back off within 30 seconds to about 1100 rpm. Drops to about 900 and starts to work its way back up to about 1300 rpm. Then it will start to switch between 1600 and 1300 and goes no lower than 1200. Consistently. Motor runs smoothly even at low rpm but the idle will no longer go back to about 850 rpm. I have pulled as many vacuum hoses as possible to see if it affects the idle. I can get the idle to go lower by plugging the crank case ventilation into the air cleaner. Which, throws a "check engine light". Have changed as many vacuum hoses as I can see. Still the same. Again, engine runs very well even with a high idle. Gas mileage is good and no strange noises. Have cleaned the throttle body and still the problem persists. Engine has about 100,000 miles and doesn't use oil. I have heard that some idle situations are nothing new to metros. Simple engine to see and work on but I am not a pro and do what I can with what I have. I don't know if a manual will help in a situation like this. The one thing that I have noticed is the idle control (black box on the back of the throttle body) does push up the idle. That is what I believe is part of the problem. But doubt if it is the culprit. It seems to work and to me that is a good sign. If it wasn't a metro, it responds like the air is on by driving the idle up and letting it off systematically. I don't have the air on. Even though it does have air. Tried it with air on and it goes higher but has the same behavior. Up idle, down idle. Any help out there. Thanks |
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| Vaultgirl | Aug 5 2012, 06:33 AM Post #2 |
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Advanced Member
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Sounds like your coolant hose to your TB is clogged or partially clogged look in the FAQ on the Home page to fix it. Common problem with TB whatever make. |
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| Johnny Mullet | Aug 5 2012, 07:26 AM Post #3 |
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Fear the Mullet
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Check and flush those small coolant tubes to and through the throttle body.
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| Memphis metro | Aug 5 2012, 08:33 AM Post #4 |
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What does this mean? Do you have something unplugged that should be plugged up? If so plug it up and leave it plugged up. If its throwing a check engine light, find the code and deal with repairing the cause of the code comming on. Replace your pcv valve. Is the tempature gauge reading normal? |
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| a.r.madillo | Aug 5 2012, 08:58 PM Post #5 |
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Fresh Fish
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Hello. Thanks everyone for their generous responses. Ok, today I checked all of the coolant hoses to the throttle body. All were clear. I even blew throught them to see it coolant cam through the intake manifold. The coolant moved freely. The second suggestion was to plug everything in. Which I did after seeing if it made any difference on the idle. Everything is plugged in. After a starts and stops, the check engine soon light shut off and did not come back on. I even checked the lines to the heater core. Everything was warm and clear. My last resort was to disconnect the black box on the back of the throttle body. I left the electrical connection on it but moved it away from affecting the throttle cable. That was one thing that I was sure causing the engine to rev up and down. That keeps it from revving to 1600 back to 1300. Now it idles about 1100 rpm. Better but probably did not solve the problem. Just made it easier to tolerate. And yes, the temperature gauge reads right in the middle. Always has. Thanks for the help. Tomorrow I will check the pcv> Anything you can think of? Thanks a.r. |
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| clarkdw | Aug 5 2012, 09:35 PM Post #6 |
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If it idles at 1100 rpm with the Idle Speed Control (the black box) backed away from the throttle link then the "screw that must not be touched" has most likely been tampered with at some point. That is the throttle stop screw, a small capped adjuster screw with a locknut that is meant to prevent the throttle butterfly from jamming shut. All things being as they should be the engine will stall with the ISC plunger backed off. The throttle stop screw being adjusted out far enough to allow the engine to idle will definitely screw up any hope of getting it to idle properly. This being said, a vacuum leak could have the same effect. NOTE: When you do the following take a VERY careful note of EXACTLY how much you adjust the screw so you know if it has been touched and can return it to the exact same location that you started at if another solution is required.. I would suggest checking the throttle stop screw adjustment first. If you find an allen wrench to fit the screw and an 8mm wrench to loosen the locknut you can then loosen off the screw till it no longer touches the throttle linkage. Make sure the ISC plunger is not touching the throttle linkage then open and close the butterfly several times by hand allowing it to snap shut the last little bit to make sure the butterfly is truly seated. Then adjust the screw in till it barely moves the linkage. All it needs to do is stop the butterfly from totally closing and wearing the throttle body or jamming shut. As close to closed as possible while still being sure it has kept the butterfly from jamming. The ISC can now take over the duties of setting the idle speed as intended. There may be other problems as well. Many times the throttle position switch will be messed with to try and fix this problem so will require resetting after. |
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| rydholm11211 | Aug 5 2012, 10:35 PM Post #7 |
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Big sky
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idle your girlfriend and it should work! I have tried it before and it is a fun ride! |
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| wayn | Aug 5 2012, 10:51 PM Post #8 |
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Really fresh fish
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Double check the timing? |
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Check and flush those small coolant tubes to and through the throttle body.


9:36 AM Jul 11