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Old 01-05-2004, 07:01 PM   #1
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Default What is valve float

What is valve float...how do you know when you get it? I've got an issue where the car is hovering at 116 and not really accelerating any more, just sort of hovers there....looks like my pulse width is dropping from 18 down to 13 or so, and running pretty lean almost like the car is starving for gas.....any ideas?

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Old 01-05-2004, 08:11 PM   #2
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Valve float occurs when the valve spring cannot close the valve as quick as the rocker arm retreats, like at high rpms.
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Old 01-05-2004, 08:38 PM   #3
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Quote:
Originally Posted by jwikoff99
Valve float occurs when the valve spring cannot close the valve as quick as the rocker arm retreats, like at high rpms.
OK so what are the symptoms? Anything like i mentioned above?
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Old 01-05-2004, 09:19 PM   #4
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Loss of high end power, backfiring at high end, tuff like that.

I wouldn't think you would have valve float where you think you may have it. I might expect it above the stock redline. Looks more lile a fuel issue to me.
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Old 01-05-2004, 09:42 PM   #5
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that isnt valve float. your injector pulse dropped when you lifted slightly. to me and what you have on your data stream chart. sounds like you need a higher oct. fuel and colder plugs.the O2 values are greatfor your rpm but at 9 psi of boost, you had alot of spark knock. low oct fuel and too hot of plugs will cause this.
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Old 01-05-2004, 10:01 PM   #6
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I've heard some SSEi'* were governed lower than the typical 128. Is this possible? Has your car been faster?

Your RPM'* arent' high enough to get float. I don't see it until I'm above 5500 rpms.
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Old 01-05-2004, 10:08 PM   #7
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Quote:
Originally Posted by willwren
I've heard some SSEi'* were governed lower than the typical 128. Is this possible? Has your car been faster?

Your RPM'* arent' high enough to get float. I don't see it until I'm above 5500 rpms.
It has been faster but not much 118 maybe? It has a lot of trouble getting past 108..I have to lift off the accel and go back down to get it into 4th gear. im running 94 octane so i doubt thats it. My plugs are only 1 step cooler so maybe I need to go 2 steps or even 3. I plan on putting a 3.2 pulley on for the dyno wednesday after I dyno the rockers.
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Old 01-05-2004, 10:10 PM   #8
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Quote:
Originally Posted by jeffrey10x2
that isnt valve float. your injector pulse dropped when you lifted slightly. to me and what you have on your data stream chart. sounds like you need a higher oct. fuel and colder plugs.the O2 values are greatfor your rpm but at 9 psi of boost, you had alot of spark knock. low oct fuel and too hot of plugs will cause this.
I wasnt lifting off the accelerator, it was almost like it was bouncing off a rev limiter.
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Old 01-05-2004, 10:11 PM   #9
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Rogue, I'd be 2 steps colder if I were you, but I smell a rat. Your car shouldn't be struggling at that speed. Mine pulls HARD through 120, pretty strong through 130, and variably weaker up to 140-145. I start creeping at that point up through 150.
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Old 01-05-2004, 10:16 PM   #10
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Quote:
Originally Posted by willwren
Rogue, I'd be 2 steps colder if I were you, but I smell a rat. Your car shouldn't be struggling at that speed. Mine pulls HARD through 120, pretty strong through 130, and variably weaker up to 140-145. I start creeping at that point up through 150.
Yea, after the dyno ill stick in 3 step cooler plugs along with the 3.2 pulley. The car pulls incredibly strong up to 108-110 then feels like its bouncing...i come off the accel then back down and it creeps up to about 116-118 and same thing starts to bounce. I guess a PCM is in order to remove the governor and change some shift points and fuel tables. I'll talk to Scott about this tomorrow.
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