 idle issue, fluctuates at times |
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| joeav8tor |
 Jul 3 2005, 09:15 PM
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#1
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Member  Group: Members Posts: 408 Joined: 23-January 05 From: mattituck, Long Island NY Member No.: 3,493  |
Hello,
my 73 2.0 with stock fuel injection is running pretty good, but at times the idle fluctuates (not surging)...when the car warms up the car usually idles at 900 rpm...then at the next light or stop sign, it will idle at about 400 rpm...the idle is not consistant...further down the road it might idle at 900 rpm when I stop again...any ideas...I recently dropped the engine and installed new vacuum, fuel lines and did a complete tune up....the AAR is working properly...anyone else experience this problem? thanks (IMG:http://www.914world.com/bbs2/html/emoticons/flag.gif) Joe Attached image(s) 
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| ejm |
Jul 4 2005, 06:58 AM
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#2
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I can see the light at the end of the tunnel Group: Members Posts: 2,708 Joined: 3-February 03 From: Massachusetts Member No.: 224 Region Association: None |
That engine pic looks like its from the factory brochure (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)
The throttle body could be worn causing the closed position to vary. Check for wear at the throttle body shaft/bushing and inside between the plate and body. |
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| bd1308 |
Jul 4 2005, 07:33 AM
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#3
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Sir Post-a-lot Group: Members Posts: 8,020 Joined: 24-January 05 From: Louisville,KY Member No.: 3,501 |
i always had funky idling problems with my FI....probably caused by my orig. FI harness or something.
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| joeav8tor |
Jul 4 2005, 08:40 AM
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#4
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Member Group: Members Posts: 408 Joined: 23-January 05 From: mattituck, Long Island NY Member No.: 3,493 |
thanks guys for the replies...Hi ED! (IMG:http://www.914world.com/bbs2/html/emoticons/flag.gif)
Joe |
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| Bleyseng |
Jul 4 2005, 09:41 AM
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#5
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Aircooled Baby! Group: Members Posts: 13,036 Joined: 27-December 02 From: Seattle, Washington (for now) Member No.: 24 Region Association: Pacific Northwest |
on a engine with 15K on it? Nah, got to be that you havn't adjusted the idle right or have a vacuum leak somewhere. Check your hoses again. Make sure the advance plate in the dizzy isn't sticking. Adjust the idle mix and rpm with the engine hot. |
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| Joe Bob |
Jul 4 2005, 09:57 AM
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#6
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Retired admin, banned a few times Group: Members Posts: 17,427 Joined: 24-December 02 From: Boulder CO Member No.: 5 Region Association: None |
LIGHTLY spraying carb cleaner at suspect areas and listening for an idle change will locate vacuum leaks.
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| BPGREER |
Jul 4 2005, 03:06 PM
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#7
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Member Group: Members Posts: 131 Joined: 29-September 04 From: SAN FRANCISCO Member No.: 2,857 |
(IMG:http://www.914world.com/bbs2/html/emoticons/agree.gif) The leak may be allowing it to idle at 900, when it warms the leak could go away and drop your rpms. The vac leaks I have had always seem to be worse when cold. |
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| Bleyseng |
Jul 4 2005, 06:23 PM
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#8
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Aircooled Baby! Group: Members Posts: 13,036 Joined: 27-December 02 From: Seattle, Washington (for now) Member No.: 24 Region Association: Pacific Northwest |
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| joeav8tor |
Jul 4 2005, 07:43 PM
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#9
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Member Group: Members Posts: 408 Joined: 23-January 05 From: mattituck, Long Island NY Member No.: 3,493 |
yeah, I probably dont have it adjusted right...I will start from scratch on the adjustment...I put about 120 miles on the car today and it ran great weather was perfect...runs great on the highway at 80 MPH)...I will still mess with it when I get a chance...Hi Geoff!
thanks guys (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) Joe |
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| MarkG |
Jul 5 2005, 10:45 AM
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#10
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Member Group: Members Posts: 314 Joined: 24-May 04 From: Colorado Springs Member No.: 2,102 |
I am experencing same issue ('76 2.0, 20k on engine, entire FI system new or rebuilt except for ECU and harness....). Up untill 2 weeks ago car could sit for a month, I would turn the key and it would start and idle perfect.
Now it wont start at all on first try (idles for a few seconds and dies; second startup and it will idle real low). It idles @ 200-300 RPM until hot (not warm - hot) then will idle @ 900 but you can hear a surging to lower RPMs and back up to 900, not not surging from 900 RPMs to higher RPM range. AAR is fine.... I lost #4 cyl, traced it to defective injector, replaced all 4 and car runs great @ speed but still have surge/low idle issue. I have spare rebuilt MPS I will try, see what happens, bound to be something simple ...... |
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| joeav8tor |
Jul 5 2005, 11:13 AM
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#11
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Member Group: Members Posts: 408 Joined: 23-January 05 From: mattituck, Long Island NY Member No.: 3,493 |
my motor and car has 14,600 original miles, I dropped the engine and tuned it up...seals, vacuum lines...etc...the car starts right up...idles around 1800 for about a minute, then drops down to around 300 until the engine is warm, then idles around 900 when warm, or sometimes still idles around 300-400...I have turned the adjustment screw on the mps, and the throttle body and have seen a difference, but I dont think it is adjusted properly. I am going to have to readjust it.
Joe |
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| Engman |
Jul 5 2005, 12:14 PM
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#12
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Zoisite Group: Benefactors Posts: 1,349 Joined: 25-March 03 From: New Albany, IN Member No.: 475  |
My vote is a vacum leak and / or TPS set wrong. You might do a check on this.
M |
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