high idle on a 5k tq
09-19-2006, 01:23 PM
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high idle on a 5k tq
my 86 5k has a 3000rpm idle, even when it is warm. it started doing this randomly one day and i cant seem to find the problem. i cant see any visable vacuum leaks and i doubt its the isv bc it does it when its warm too. the only thing i can think of is that my wg diaphragm is cracked so would that cause a big enough vacuum leak to idle that high?
on a side note, if anyone is selling a wg diaphragm for cheap, lmk...
on a side note, if anyone is selling a wg diaphragm for cheap, lmk...
09-19-2006, 01:35 PM
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Re: high idle on a 5k tq
Pretty hard to "see" a vacuum leak. Best bet is to make yourself a leak tester.<ul><li><a href="http://www.blackfoot.net/~hlm5860/Tester.html">vacuum leak testing</a></li></ul>
09-19-2006, 01:51 PM
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Check the throttle body switch and wiring...
I had a similar problem manifest itself during testing for (what turned out to be) an ISV leak. The switch resistances checked out per SJM/Bentley, but one of the terminals in the connector did not have continuity to the ECU connector - turned out to be a broken wire.
Cheers!
Cheers!
09-19-2006, 02:19 PM
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Re:had same problem couple of days ago...
My 5KTQ suddenly started to idle at 3K rpm, cold or hot doesn't matter. Problem was in idle valve.
Replaced with working used one - works great!
Replaced with working used one - works great!
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09-19-2006, 03:36 PM
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Michelin Man hose torn?
Check bottom of the Intercooler to intake manifold corrugated air hose known as the Michelin Man hose for a tear. The turbo heat cooks the rubber, which eventually tears. Another result is reduced boost, but more noticeable is erratic raised idle when manifold vacuum is high.
Also, check resistance value of the idle thermosensor at the upper radiator hose junction. You'll find the table of Resistance vs Temperature on sjmautotechnik.com.
Also, check resistance value of the idle thermosensor at the upper radiator hose junction. You'll find the table of Resistance vs Temperature on sjmautotechnik.com.
09-19-2006, 03:49 PM
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It's either...
Bad or dirty ISV...
Bad ISV control unit or wiring...
Vacuum leak...
Bad ISV temp sensor...
Missing or backed out idle screw...
My moneys on the ISV or vacuum leak.
Steve
Michigan
Bad ISV control unit or wiring...
Vacuum leak...
Bad ISV temp sensor...
Missing or backed out idle screw...
My moneys on the ISV or vacuum leak.
Steve
Michigan