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| Failed Instpection - Idles to high; Fast idle | |
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| Tweet Topic Started: Apr 25 2011, 12:22 PM (1,720 Views) | |
| lafter | Apr 25 2011, 12:22 PM Post #1 |
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I ran my Metro threw Inspection today & it failed the emissions test because its idling to high 1340rpms .. it needs to be between 700-1300 rpms before they can run the emissions test. Is there a quick way to do this? .. say with a screwdriver and the carburetor? just to get it inspected? I have read a ton of info about fast idle with these cars .. and to be honest its kind of overwhelming .. I would like to wait on these fixes until my service manuals come in. IAC Function; Any Other Function Besides Idle? can you replace the fast idle control valve in the TB High "hunting" idle Fast Idle Low MPG High Idle high idle... "Hanging" Idle Thanks for any help |
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| Coche Blanco | Apr 25 2011, 01:30 PM Post #2 |
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Troll Certified
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You could have a vacuum leak? |
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| Johnny Mullet | Apr 25 2011, 08:38 PM Post #3 |
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Fear the Mullet
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I suspect you have a vacuum leak somewhere or the throttle stop screw needs adjusted if it was already molested. |
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| Bad Bent | Apr 26 2011, 12:22 AM Post #4 |
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Facetious Educated Donkey
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I transcribed these directions for the Idle Speed Set Screw. But I suspect the vacuum leak also. Replacing the vacuum hoses may fix it. While you have a '94 and my Chilton manual says you don't have a Throttle Body ...here is the procedure for adjusting the Idle Speed Set Screw;1. Confirm the following prior to checking or adjusting the idle speed. a. Check that eh lead wires and hoses of the engine emission control system are connected correctly. b. Check that the accelerator cable has 0.12-0.29 in. (3-5mm) freeplay when the engine is at operating temperature. c. Check that the ignition timing is within specification. Factory is 5-6o BTDC and 10-12o BTDC for manuals from '85-'88. Automatics 5o or 6o BTDC. 2. Place automatic transaxle gear shift lever in 'P' position or manual transaxle gear shift lever in NEURTAL position and set the parking brake. 3. Ensure that the lights, heater fan, rear defogger, cooling fan and air conditioner are OFF. 4. Ensure that air cleaner is installed correctly. 5. Remove cover on idle speed adjusting screw. 6. Start engine and warm engine to normal operating temperature. 7. Install a spare fuse into the DIAG SW connector in the fuse block under the left side of the dash. 8. Check and adjust idle speed to specification. Turn the idle speed adjusting screw in to decrease the idle and out to increase idle. I have both a tachometer and 'old school' Tach/dwell meter from Acton. Harbor Freight currently sells a Multimeter with Tachometer Kit for $36 ($29 on sale) 9. If equipped with air conditioning, check and adjust the air conditioner idle speed vacuum solenoid valve. 10. With idle speed correct, turn air conditioner ON. 11. Check that engine idle is within specification or slightly higher. If not, adjust air conditioner vacuum solenoid valve adjusting screw to obtain correct idle. 12. Turn air conditioner OFF and check that the idle speed is within specifications. Note: On some vehicles, a slightly higher idle setting on the vacuum solenoid valve may be needed to maintain proper idle characteristics with the air conditioning system operating. 13. After adjusting idle speed remove the spare fuse from the connector. Proper idle for 1991-2000 Metros is 800 for manual and 850 for automatics. 1985, 87, 88, and 90 1.0 models have 750 rpm for manuals. |
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| lafter | Apr 26 2011, 09:21 AM Post #5 |
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Thanks. |
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| duff_remle | Apr 26 2011, 08:00 PM Post #6 |
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Advanced Member
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I recommend the high idle ... thread I was having high idle and had no vac leak & turning the idle adjust screw in all the way dropped it to 1000rpm at best. It turned out that the high idle bypass valve in the throttle body needed cleaning. The air feed to this valve is a about a 3/8" diameter hole in the throttle body below and behind the fuel injector. If you plug this hole and the idle drops below 1000rpm (depending on how you have your idle screw adjusted, mine dropped to @ 500 rpm) its at least part of your problem. It's actually quite easy to clean. See high idle ... for details/references. |
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| chubart | Apr 26 2011, 08:03 PM Post #7 |
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Nice detailed post BB
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| Bad Bent | Apr 26 2011, 09:38 PM Post #8 |
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Facetious Educated Donkey
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Thanks chubart, and it would make a good movie script, eh. As Johnny Mullet mentions there is the Throttle Stop Screw and this is different from the Idle Speed Screw. In order of adjustment it would be the Throttle Stop Screw-cable tension-TPS-Idle Speed Screw, IIRC. My PO had adjusted the FACTORY SET - NEVER ADJUST Throttle Stop Screw which is an Allen Screw with lock nut that stops the rotation of the Butterfly Valve in the Throttle Body. (TB). It should be set so that the throttle does not stick. I know that sounds inaccurate but if you back the Allen screw off a little the idle will drop. BUT the throttle may stick and that is a BAD THING. (You may have to readjust the idle, cable and TPS if you adjust the Allen Screw). I know my PO adjusted the FACTORY SET - NEVER ADJUST Throttle Stop Screw (TSS). The idle was very high and adjusting the Idle Speed Screw did nothing to lower the idle. I had no choice. So I carried an Allen Wrench and small 9mm(?) box end wrench with me and drove around unscrewing the TSS until it stuck and then screwing it in until it stopped sticking. Quite a few stop, adjust, drive, stop, adjust drive cycles. So... have fun and it would be a really good idea to mark your starting place or make one adjustment of maybe 1/4 turn and test it. If you screw up you know what to undo to fix it.
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...here is the procedure for adjusting the Idle Speed Set Screw;

![]](http://z3.ifrm.com/static/1/pip_r.png)
Quite a few stop, adjust, drive, stop, adjust drive cycles.
9:35 AM Jul 11