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Old 10-24-2009, 06:49 AM   #1
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Exclamation Car does not set back to idle for 2-3 seconds.

Hi Guys,

Something weird is happening with my VRX-2 when i give it full throttle and release it so it runs back to idle the servo returns back to idle position. The carburetor also fully shuts of so no air is getting through from what i can see.

Also it seems to be running still on half throttle but only for a few seconds, it seems to be burning fuel as well. Not come across this problem before at 1st i thought it may be a radio problem but its not and nothing is keeping the air intake open.

As far as i can see there must be some sort of air leak in the carburetor, but it is also burning fuel.

Any ideas?
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Old 10-24-2009, 07:05 AM   #2
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use the search button...or look at the top of this page under the "tuning bible"...but sounds as if the low end is rich and high end is a little lean and then loading up after a couple seconds dropping the idle down...from what it sounds like you need torichen up the op end a coule hours and lean out the low end until you get a steady "higher then normal idle" and then re adjust your idle speed screw to drop the idle down.

Ryan
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Old 10-24-2009, 07:16 AM   #3
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If the throttle feels like it's hanging up after a full throttle run you're probably lean on the high side needle; I had the same issue a few weeks ago. I was also too rich on the bottom and was seeing temps in the 215 range even though I was lean up top.
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Old 10-24-2009, 07:19 AM   #4
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Quote:
Originally Posted by blktransam View Post
use the search button...or look at the top of this page under the "tuning bible"...but sounds as if the low end is rich and high end is a little lean and then loading up after a couple seconds dropping the idle down...from what it sounds like you need torichen up the op end a coule hours and lean out the low end until you get a steady "higher then normal idle" and then re adjust your idle speed screw to drop the idle down.

Ryan
+1 to this I had the same problem at one point this year. I richened the top 6 hours, reset the low and idle, till it acted like it should then race tuned from there. About half the "air leak" problems I have seen where actually tuning problems.
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Old 10-24-2009, 09:20 AM   #5
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he cant tune a motor. but he wants to set the world record for the farthest jump?
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Old 10-24-2009, 09:22 AM   #6
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sounds like it...
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Old 10-24-2009, 09:43 AM   #7
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+2 on the top too lean. When the throttle is wide open the high speed needle descides how much fuel goes to the engine if there is not enough then when you let off it will have a lean eeeeeeeeeeee sound until it has enough fuel to drop the idle down. Try richening 1 hour and then run it for 2 - 3 minnand recheck. Make sure you always run the car inbetween carb adjustments.
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Old 10-24-2009, 10:00 AM   #8
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It probably screams down the straights (or on the street) though !!
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Old 10-24-2009, 10:08 AM   #9
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high end needle controls the fuel at wot, low end controls fuel at idel and at take off...liek I said it prb. a combination of lean top end and rich low end.
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Old 10-24-2009, 10:18 AM   #10
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Lean the idle gap and LSN... Don't mess with HSN
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Old 10-24-2009, 10:25 AM   #11
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Quote:
Originally Posted by coviello View Post
he cant tune a motor. but he wants to set the world record for the farthest jump?
A blind person can't see but they can play musical instruments better than most sited people.

Nothing wrong with wanting to learn
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Old 10-24-2009, 10:38 AM   #12
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Hi All,

Ill have a play around with the HSN i know its set to lean because the engine overheats and hesitates after a tank of fuel. Didn't think this would have an affect on the return to idle.

Thanks Guys
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Old 10-24-2009, 12:29 PM   #13
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Quote:
Originally Posted by xnitrorc View Post
Hi All,

Ill have a play around with the HSN i know its set to lean because the engine overheats and hesitates after a tank of fuel. Didn't think this would have an affect on the return to idle.

Thanks Guys
all the needles effect each other , some minimal , some much more .

once you find a balance in the carb (novas) it is usually pretty close to in the ball park and may need minor tweaks either way but the balance will stay pretty close .

such as lean the high speed and richen low speed or richen high speed and lean low speed . adjust idle to suit .
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