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Registered User
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Checking idle control valve (ICV)
Good morning - hope everyone had a good weekend.
I am trying to sort of an idle issue with my '74 with a 3.2 and I just pulled the ICV. I cleaned it with carb cleaner and when i shake it I can hear the piston moving. I have 40 ohm resistance between the outer pins, and 20 between inner and outer. That suggests that the ICV should be in working order, correct? Thanks!
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1967 912 (now w/ 50% fewer random holes in it) 911 w/ 3.2 1974 914 (3.2L swap underway) 1984 928s (S4 engine and suspension), 1987 928S4 |
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That Guy
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You can use a 9v battery and put power on the ISV; this will cycle the valve open and closed.
Bench testing Carrera Idle Control Valve When you put the ISV back on, you can reset your base idle by bypassing the ISV and adjusting the air bypass screw on the throttle body. This will give you a good baseline to start from.
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Jon 1988 Granite Green 911 3.4L 2005 Arctic Silver 996 GT3 Past worth mentioning - 1987 924S, 1987 944, 1988 944T with 5.7L LS1 |
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Registered User
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Thanks Jon
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1967 912 (now w/ 50% fewer random holes in it) 911 w/ 3.2 1974 914 (3.2L swap underway) 1984 928s (S4 engine and suspension), 1987 928S4 |
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Registered
Join Date: Aug 2008
Location: sectors R&N, SE Pa
Posts: 3,117
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When plugged back in, and with the key ON (eng off), you'll feel it vibrate and might hear the buzz. This tells you the DME is powering/ driving it.
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Dan '87 Targa Carrera 3.2 - Fabspeed Cat Bypass, M&K Muffler, SW Chip Venetian Blue |
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Registered User
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Quote:
Thanks!
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1967 912 (now w/ 50% fewer random holes in it) 911 w/ 3.2 1974 914 (3.2L swap underway) 1984 928s (S4 engine and suspension), 1987 928S4 |
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Registered
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My '87 started surging pretty badly. I removed the ICV, cleaned it, and verified it worked using a 9 volt battery. However, the engine still surged. I ultimately bought a used ICV and swapped it out. Haven't had a surging problem since.
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1987 911 Carrera coupe - Guards Red 2010 997.2 C4S 6-Speed 2005 Mini Cooper Convertible (R52) - Wife's car 1977 VW Bay Window Camper Bus |
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Registered
Join Date: Dec 1999
Location: Novato, CA
Posts: 4,740
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Mine had the same problem. Found out someone installed the ICV backwards with the arrow pointing up.
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Caveman Hammer Mechanic
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It's a consumable, got one online problem solved for another 30 years....
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1984 Carrera El Chupacabra 1974 Toyota FJ40 Turbo Diesel "Easy, easy, this car is just the right amount of chitty" "America is all about speed. Hot,nasty, bad ass speed." Eleanor Roosevelt, 1936 |
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Member 911 Anonymous
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OP, so what was the issue to suspect the ICV?
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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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