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GT40 idle flare-up |
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SharkSN 
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Joined: August-23-2010 Location: Sproat Lake Status: Offline Points: 119 |
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 Topic: GT40 idle flare-upPosted: August-01-2011 at 6:07pm |
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I have the '97 engine the high idle on start-up and finally staying there (sticking) I decided to do something and quickly came up with solution.
Is it only the 97 motors?? http://www.youtube.com/watch?v=_SbLGE3UjQQhttp://www.youtube.com/watch?v=_SbLGE3UjQQ |
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NAUTIQUEjunky
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Joined: July-17-2010 Location: Henderson NC Status: Offline Points: 210 |
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Posted: August-02-2011 at 1:47am |
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Have you tried taking the IAC off and cleaning it with carb cleaner??
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1977 MasterCraft Stars&Stripes
1994 Ski Nautique 2000 Super Air Nautique 1986 Ski Nautique 2001 1999 Sport Nautique gt40 current |
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SharkSN
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Joined: August-23-2010 Location: Sproat Lake Status: Offline Points: 119 |
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Posted: August-02-2011 at 3:39am |
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Yes that is what I went for I used LPS #2 on it. Might have to get a new one anyway....but to cure the flare up (PCM ECU) that has been there since new (my buddies '97 same thing) I manufactured a restrictor plate. Works great.
I think they fixed it in '98 tho correct?? and 1996 GT40's don't do it either. |
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8122pbrainard
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Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41040 |
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Posted: August-02-2011 at 8:27am |
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Paul,
LPS#2 is a lubricant and not really a cleaner. Where you trying to clean or lubricate? |
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SharkSN
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Joined: August-23-2010 Location: Sproat Lake Status: Offline Points: 119 |
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Posted: August-02-2011 at 5:36pm |
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true... I use it for ISV's, air valves, vacuum actuators etc. on Porsches does the job and hangs in there. far superior to say WD40.
My GT40 is purring like a kitten with the restrictor in there. However it will on occasion go about 50-100 rpm high and stay there, and to me that seems like the IAC (idle air conrol) is hanging up but not sure. it doesn't have the same bumpy ride as when the Porsche ISV's stick up. |
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Luchog
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Posted: August-02-2011 at 9:07pm |
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I dont think I understand what is being discussed here... can anyone enlight me?
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NAUTIQUEjunky
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Posted: August-02-2011 at 11:24pm |
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IAC Idle Air Control valve all EFI motors have one, it controls idle in short term on the engine.. They do become "carbonized" after some age but lots of other sensors,have input to Idle control as well. Intake air temp sensor, map sensor ect...Coolant temp sensor, in a boats case it would be measuring lake water temp..
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1977 MasterCraft Stars&Stripes
1994 Ski Nautique 2000 Super Air Nautique 1986 Ski Nautique 2001 1999 Sport Nautique gt40 current |
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Luchog
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Joined: April-17-2007 Location: Argentina Status: Offline Points: 2135 |
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Posted: August-02-2011 at 11:31pm |
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All EFI engines I've driven rev a little higher at start up, specially when cold.
So still I dont follow what's going on here. |
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M3Fan
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Joined: October-22-2005 Location: United States Status: Offline Points: 3185 |
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Posted: August-03-2011 at 1:51am |
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Idle flare up was fixed with a later version of the GT40 ECU. That could be part of the problem. Do you have a number visible on your ECU?
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2000 SN GT40 w/99 Graphics/Gel
2016 SN 200 OB 5.3L DI https://forum.fifteenoff.com |
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SharkSN
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Posted: August-04-2011 at 2:50pm |
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i have the original early 1997 ecu. my boat was the sea world display boat (sat on bunks outside seaworld san diego for the summer of 1997)
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M3Fan
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Posted: August-04-2011 at 4:51pm |
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SkiDim carries the newer ECU, it's something like 550.00.
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2000 SN GT40 w/99 Graphics/Gel
2016 SN 200 OB 5.3L DI https://forum.fifteenoff.com |
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