idle question

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kingpin

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OK my first post, I have a KM sc truck with the 30.5 have ran 3 tanks of fuel, so now all of a sudden I start it up and idles good for about 30 secounds then the idle goes low then back to normal but dose not die, it started this all of a sudden. I haven't had any other problems with it. it runs great but just started this idle problem, any help will be great.:mad:
 
If it was new to start with, it will probably have been rich / slightly rich.
This permits cooler running, and also generally permits better lubrication, during the 'bedding in', running in, which does happen to some extent with these engines.
That said, it probably means the plug's slightly sooty - I'd check the plug.

It may require replacement - consider this an option.

I'd also check all HT connections - might be a little loose.
Always check all screws and bolts on a regular basis, as these things vibrate a lot, and all can work loose, eventually.

Al.
 
atom3624 said:
If it was new to start with, it will probably have been rich / slightly rich.
This permits cooler running, and also generally permits better lubrication, during the 'bedding in', running in, which does happen to some extent with these engines.
That said, it probably means the plug's slightly sooty - I'd check the plug.

It may require replacement - consider this an option.

I'd also check all HT connections - might be a little loose.
Always check all screws and bolts on a regular basis, as these things vibrate a lot, and all can work loose, eventually.

Al.
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also noticed some fuel between the gasket of the chrome pipe, also spark plug is paper brown looking. idles fine then idles lowers then goes normal, could it be the card maybe?.
 
mechanike said:
fill the tank up.mine runs weird at less than a half tank,,,,,,,,,,,,,,,,,,,,,
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that's what I thought also but didnt change, I mean she run's fine but when I stop and wait about 30 secounds it drops the idle then it goes back to normal. didnt get a chance to work on truck been working all kind of weird hours.:(
 
as luck will have it mine is doing it now.i'll spray around,tighten up and get back to you.probably carb/leak related.i have a walbro i was fixin to try anyway,,,,,,,,,,,,,,,,,,
 
mechanike said:
as luck will have it mine is doing it now.i'll spray around,tighten up and get back to you.probably carb/leak related.i have a walbro i was fixin to try anyway,,,,,,,,,,,,,,,,,,
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man you too?:( but like I said drops down for about 5 to 10 seconds then back to normal, must be the carb, again working crazy hours and have done nothing to it yet. yes let me know what you find out, good luck.
 
mechanike said:
the right most one.the one that controls the idle.mine is at one turn from closed
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That would be the L needle, so you fooled around with it and now is all good. your idle is fine, did you have to fool around with the idle screw any?. the L needle controls the fuel to air ratio, so when you fooled around with it did your idle raise or lower and again you had to adjust the idle screw correct.
 
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I was going to suggest checking your need settings, but from what you are saying it sounds more like your hsn being rich since your idle dropped when letting off the throttle. Or your lsn being lean. It can either but it just depends on how high your idle is & how your take off & top end performance is. Videos come in handy when trying to get help diagnosing an engine problem.
 
when i turned the lsn counterclockwise the idle went up with it.i'll get some time to run it more and let you know if it remains fixed.did you spray wd-40 around the carb?,,,,,,,,,,,,,
 
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