Not so Good Vibrations

[5 Liter Eater]

I have a vibration coming from the gas pedal. It is pretty subtle until after ~6k when it becomes much more pronounced all of the sudden. I have some theories:

1. SC belt is slipping and re-gripping at higher RPMs. The problem seems to have started a couple of days ago after I took off the SC belt to verify smooth operation of the SC by turning it by hand which felt good. (I was, and still am, paranoid about the oil level in the SC since I didn't have the good sense to check it before putting it in). I was a little worried about having the belt too tight so I didn't tighten it as much as I had it before. It worked fine until a high RPM spin and it squeaked once but hasn't ever since, but the vibration is now there instead. Anyone think this is likely it? I'm not convinced.

2. Damaged/broken valvetrain components, more specifically VTEC pins/rockers. I adjusted the valves some weeks ago. Everything looked OK but if one or more VTEC pins are damaged or broken I could see the uneven valvetrain causing a vibration.

3. Clutch disk opt of balance and becoming misaligned. The clutch has always been a lot harder than stock even though the PP doesn't appear to grip like an aftermarket one.

Has anyone had similar experiences? I am preparing to go 9 PSI soon and would like to clear this up first. My first step will be to tighten the belt, if that doesn't do anything I will pull the VTEC wire off the solenoid with the thinking that if VTEC is the problem that staying on the small lobes would keep it from happening.

Thanks guys,



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Bill Winters
Houston, TX
'94 GSR w/ JRSC @ 6 PSI, Cartech FMU, AEM fuel rail and homemade CAI
(ENDYN stepper pully, GS 342 and RC 310's in the garage waiting)

[5 Liter Eater]

TTT

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Bill Winters
Houston, TX
'94 GSR w/ JRSC @ 6 PSI, Cartech FMU, AEM fuel rail and homemade CAI
(ENDYN stepper pully, GS 342 and RC 310's in the garage waiting)

[schwett]

i have a gas pedal vibration as well, but on a prelude. 3/4 prelude jrsc owners i know well have it too. mine comes on only between 3500 and 5000rpm, and only when you gently let off the gas. if your foot is down, or off the gas, it's not there. i believe it's because the blower itself is vibrating sympathetically, and the throttle cable is attached to the blower.

is your vibration similar? is the throttle cable attached to the blower on a teg too?



[img]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by 5 Liter Eater:
I have a vibration coming from the gas pedal. It is pretty subtle until after ~6k when it becomes much more pronounced all of the sudden. I have some theories:

1. SC belt is slipping and re-gripping at higher RPMs. The problem seems to have started a couple of days ago after I took off the SC belt to verify smooth operation of the SC by turning it by hand which felt good. (I was, and still am, paranoid about the oil level in the SC since I didn't have the good sense to check it before putting it in). I was a little worried about having the belt too tight so I didn't tighten it as much as I had it before. It worked fine until a high RPM spin and it squeaked once but hasn't ever since, but the vibration is now there instead. Anyone think this is likely it? I'm not convinced.

2. Damaged/broken valvetrain components, more specifically VTEC pins/rockers. I adjusted the valves some weeks ago. Everything looked OK but if one or more VTEC pins are damaged or broken I could see the uneven valvetrain causing a vibration.

3. Clutch disk opt of balance and becoming misaligned. The clutch has always been a lot harder than stock even though the PP doesn't appear to grip like an aftermarket one.

Has anyone had similar experiences? I am preparing to go 9 PSI soon and would like to clear this up first. My first step will be to tighten the belt, if that doesn't do anything I will pull the VTEC wire off the solenoid with the thinking that if VTEC is the problem that staying on the small lobes would keep it from happening.

Thanks guys,

<HR></BLOCKQUOTE>



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[AMslp_late]

When my JRSC GSR was running...I had a vibration from the gas pedal from 6000 thru 8000. I just thought it was all of that insane horsepower trying to go somewhere.
I never really seriously thought that it was something wrong. That engine is not made to have that much horsepower so some vibration coming through the pedal would be understandable in my opinion.

Put some harder motor mounts in and see what that feels like.

Austin

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96gsr 4door w/jrsc at 8psi---crazy new mods in the works
Current daily driver = 88 civic LX hybrid JDM B16A5

[Holden]

How can you feel vibration in the gas pedal when you have it mashed to the floor? It could be coming from anywhere.

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Greg Holden
96 GSR, JSRC @10psi, All the Goodies!
Best 1/4 ==&gt; 13.556 @ 105.29mph
My JRSC Install Site

[AMslp_late]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Holden:
How can you feel vibration in the gas pedal when you have it mashed to the floor? It could be coming from anywhere.

<HR></BLOCKQUOTE>

True, True

[5 Liter Eater]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Charged R:
Have you already tried revving the engine to 6K from the engine bay using the throttle cable? Might be able to locate the vibration. Be careful if you try this approach - watch out for belts / fan - you know.

<HR></BLOCKQUOTE>

That's another idea, and if it existed without load it would make it a lot easier to determine, although I'm not thrilled about revving that high unloaded.



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Bill Winters
Houston, TX
'94 GSR w/ JRSC @ 6 PSI, Cartech FMU, AEM fuel rail and homemade CAI
(ENDYN stepper pully, GS 342 and RC 310's in the garage waiting)

[AMslp_late]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by 5 Liter Eater:

AMslp_late: Sounds exactly like what I am experiencing!! What do you mean when it was running?!? Did it blow up?

<HR></BLOCKQUOTE>

Yes, my car got seriously injured...in march of this year. I melted piston #3 in a high speed dash to avoid the law.
I have therefore used this as an excuse to spend an insane amount of money to make my engine stronger...resleave, pistons, rods, valve train, yada yada yada. Jim Helbing is the man that is helping me with my dream.



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96gsr 4door w/jrsc at 8psi---crazy new mods in the works
Current daily driver = 88 civic LX hybrid JDM B16A5

[5 Liter Eater]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Holden:
How can you feel vibration in the gas pedal when you have it mashed to the floor? It could be coming from anywhere.
<HR></BLOCKQUOTE>

True, I'll feel down there w/ my othe foot and see if I can feel it in the floorboard.

Schwett: The GSR throttle cable is mounted somewhat like yours but not exactly. I could see a vibration like you are talking about but this is all of the sudden at ~6500. It's got me worried enough to yank the SC and check the oil and inspect the rotors and gears.

AMslp_late: Sounds exactly like what I am experiencing!! What do you mean when it was running?!? Did it blow up?


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Bill Winters
Houston, TX
'94 GSR w/ JRSC @ 6 PSI, Cartech FMU, AEM fuel rail and homemade CAI
(ENDYN stepper pully, GS 342 and RC 310's in the garage waiting)

[Charged R]

Have you already tried revving the engine to 6K from the engine bay using the throttle cable? Might be able to locate the vibration. Be careful if you try this approach - watch out for belts / fan - you know.

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98ITR, JRSC, AEM/CAI, Comptec