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Throw it on the ground!
Join Date: Aug 2006
Location: Atlanta, GA
Posts: 2,566
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Elevated & Surging Idle on 3.2 Ideas?
This is new. Normal idle has been 900 to 1000 rpm. All of sudden that has elevated to 1,200 with a regular cycle/pulse up to 1,300 and back to 1,200 every few seconds. What would cause this?
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Mark 1987 911 Coupe Granite Green Metallic My Cousin's Wife's Sister's Husband is a Lawyer. |
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07-14-2011, 04:14 PM
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Member 911 Anonymous
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Have you check the throttle linkage to see if anything is binding? Is the Idle Switch connecting/clicking at rest?
Tap on the ICV to see if settles down. Check the vacuum Y lines behind the TB to either side to those bell diaphrams ( one being the FPR ). My buddy's 86 was disconected on the passenger side one.
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'85 Carrera Targa Factory Marble Grey/Black * Turbo Tail * 930 Steering Wheel* Sport Seats * 17" Fuchs (r) * 3.4 * 964 Cams * 915 * LSD * Factory SS * Turbo Tie Rods * Bilsteins * Euro Pre-Muff * SW Chip on 4K DME * NGK * Sienes GSK * Targa Body Brace PCA/POC Last edited by DRACO A5OG; 07-14-2011 at 04:32 PM.. |
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07-14-2011, 04:22 PM
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Call 911
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Check the torque values on the intake manifold-to-cylinder head nuts. These have a tendency to loosen due to thermal cycling. I had an unstable idle on my 1988 3.2; checked the torque on said nuts and most were only finger tight. A re-torque to the service manual value cured the idle instability.
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Dave Kirk My Porsche restoreth my soul. |
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07-14-2011, 04:24 PM
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Throw it on the ground!
Join Date: Aug 2006
Location: Atlanta, GA
Posts: 2,566
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07-14-2011, 05:38 PM
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Throw it on the ground!
Join Date: Aug 2006
Location: Atlanta, GA
Posts: 2,566
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07-14-2011, 05:40 PM
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Member 911 Anonymous
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Quote:
__________________
'85 Carrera Targa Factory Marble Grey/Black * Turbo Tail * 930 Steering Wheel* Sport Seats * 17" Fuchs (r) * 3.4 * 964 Cams * 915 * LSD * Factory SS * Turbo Tie Rods * Bilsteins * Euro Pre-Muff * SW Chip on 4K DME * NGK * Sienes GSK * Targa Body Brace PCA/POC |
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07-14-2011, 06:25 PM
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Registered
Join Date: Dec 1999
Location: Novato, CA
Posts: 4,740
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A rich condition due to a bad 02 sensor might cause this too.
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07-15-2011, 07:23 AM
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Large Registered Member
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Don't forget Fuel injector's too. If they are original, it's time to send them out to be overhauled!!!!!
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'85 Carrera Coupe, Marble Grey #118 JP/R6 '93 Lexus SC400, '00 Ford F-150 '70 911T- 2.7 (SOLD) |
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07-15-2011, 07:27 AM
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Registered
Join Date: Jan 2004
Location: Spain
Posts: 62
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Idle switch
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07-15-2011, 08:03 AM
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Registered
Join Date: Jul 2002
Location: Southern California
Posts: 5,067
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Had a similar problem. A mixture adjustment solved it.
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1984 Targa |
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07-15-2011, 08:13 AM
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Registered
Join Date: Oct 2004
Posts: 15,612
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All good suggestions. Due to the sudden onset, I'd pull the icv when warm, and re-connect the elec - make sure the valve is half open. Be sure that it moves freely.
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07-15-2011, 09:34 AM
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Registered
Join Date: Oct 2006
Location: Los Angeles
Posts: 510
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Re the idle, there have been a lot of threads on this (3.2s seem prone to bouncy idle). So use the search button too as this problem can have multiple causes.
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1986 Targa 1968 MGB (2) |
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07-15-2011, 10:14 AM
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Throw it on the ground!
Join Date: Aug 2006
Location: Atlanta, GA
Posts: 2,566
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Injectors are good. All sent to Witchhunter for reconditioning at time of engine swap 2 yearss ago.
Problem appears to be intermittent. Did it again this morning on the way to work. Not out to lunch and not on the drive home 
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Mark 1987 911 Coupe Granite Green Metallic My Cousin's Wife's Sister's Husband is a Lawyer. |
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07-15-2011, 04:12 PM
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Registered
Join Date: Jun 2009
Location: Manhattan Beach, California. Factory Delivery-Original owner-Retired engineer
Posts: 5,238
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Idle issues
If none of the above resolve your issue:
1. Remove and clean the ICV, and reset the idle by shorting the connector located on the engine compartment fuse panel as per the Bentley. 2. check for a disconnected/defective vaccum line.    
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1986 911 Targa. Per Road and Track magazine: Only in L.A.: In the window of a bar in Hermosa Beach, California. "Happy Hour prices during all car chases." |
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07-15-2011, 04:39 PM
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Member 911 Anonymous
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Great pics Gerry
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'85 Carrera Targa Factory Marble Grey/Black * Turbo Tail * 930 Steering Wheel* Sport Seats * 17" Fuchs (r) * 3.4 * 964 Cams * 915 * LSD * Factory SS * Turbo Tie Rods * Bilsteins * Euro Pre-Muff * SW Chip on 4K DME * NGK * Sienes GSK * Targa Body Brace PCA/POC |
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07-15-2011, 06:57 PM
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86 Carrera Coupe
Join Date: Apr 2008
Location: Holyoke, Massachusetts (western end of state)
Posts: 425
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In the last picture there is a braided vacuum line next to the rubber ones and just above the "Y" vacuum lines, can anyone tell me where this line goes to or comes from? I finally had some time to check stuff out (crappy idle and idling very rich with no response from air fuel mix adjustment. Found the "Y" pulled off and the braided line missing (or maybe fallen down somewhere I can't see). There is a braided line over by the oil filler tube that goes down behind the engine
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07-17-2011, 02:39 PM
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Marble Grey
Little Deutch Coupe
