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Old 04-09-2010   #1
Z51JEFF
 
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Default Off idle stumble.

When my car is idling if you hit the gas its got a minor stumble.The injectors are fairly new as is the filter.The cars got a Haibeck chip and K&N filter.Also I can hear vacuum at the PCV valves,if I move the fitting around it gets louder.Thanks.
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Old 04-09-2010   #2
jonszr1
 
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Default Re: Off idle stumble.

do you have the original rubber tube that holds the pvc valves>? if so it may be going south. also the factory top can leak. .alot of guys use little hose clamps to hold the pvc valves in tight. i got tired of it leaking and just bit the bullet and got one of curt whites silicone pvc set ups
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Old 04-10-2010   #3
Z51JEFF
 
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Default Re: Off idle stumble.

Quote:
Originally Posted by jonszr1 View Post
do you have the original rubber tube that holds the pvc valves>? if so it may be going south. also the factory top can leak. .alot of guys use little hose clamps to hold the pvc valves in tight. i got tired of it leaking and just bit the bullet and got one of curt whites silicone pvc set ups
It is the original top piece,thats where its leaking from.The main pipe is still in good shape.Would this cause the stumble?If I cant find a new top piece at a reasonable price I might take the entire PCV pipe out,clean all the oil off and seal it up with some black urethane.
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Old 04-10-2010   #4
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Default Re: Off idle stumble.

Quote:
Originally Posted by jonszr1 View Post
do you have the original rubber tube that holds the pvc valves>? if so it may be going south. also the factory top can leak. .alot of guys use little hose clamps to hold the pvc valves in tight. i got tired of it leaking and just bit the bullet and got one of curt whites silicone pvc set ups
I agree. KWRacing's stuff was a good answer to the annoying small leaks in the old OE rubber PCV stuff.

I still used a combo of small screw clamps and those old fashioned squeeze clamps (from the old fuel filter kits that used to come with a fram G1 in-line filter) on the samco replacement hoses. The only weak spot left is where the PCV hard lines plug into the 90* els at the I/H's. Those things are prone to leak also.
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Old 04-11-2010   #5
jrd1990zr1
 
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Default Re: Off idle stumble.

Quote:
Originally Posted by Z51JEFF View Post
It is the original top piece,thats where its leaking from.The main pipe is still in good shape.Would this cause the stumble?If I cant find a new top piece at a reasonable price I might take the entire PCV pipe out,clean all the oil off and seal it up with some black urethane.
Jeff,

Is the upper piece (the F rubber piece), what you are looking for? Is your part cracked?

What do you consider a reasonable price?

John
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Old 04-11-2010   #6
Z51JEFF
 
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Default Re: Off idle stumble.

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Originally Posted by jrd1990zr1 View Post
Jeff,

Is the upper piece (the F rubber piece), what you are looking for? Is your part cracked?

What do you consider a reasonable price?

John
A reasonable price meaning not getting raped,as in 4 times what it cost new.All the PCV parts are fine,just a poor design I think.The top part that goes on the PCV valves is fine as long as it doesnt have oil on it,it gets oily and can slip off.Ive come up with something that fixed it.The easiest fix here is to use a long wire tie around the hose and the fitting,didnt want to do that.What I did was wrap some thread around the PCV outlet right under the nipple.I wrapped the thread just a little bigger than the nipple and then I sealed the thread with epoxy to keep it uniform.Why did I use thread?The thread has a course surface that will contact the inside of the fitting and wont come loose as easily.I could have used an O ring but once it get oily Im back to square one.This car has had a slightly rough for as long as Ive owned it and now the idle is smooth,dont know if cleaning the TB fixed that or getting a nice seal on the PCV system.
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Old 04-12-2010   #7
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Default Re: Off idle stumble.

The tie wrap thing worked just fine till I broke down & bought the samco kit to replace all of it.

You want a NOS F-hose? I'll look up what I paid for it from chevy when they were still in stock. I bought a few for the reason you just described....they get a bit oily & they start to slip. I figured I could swap out and clean the oiled up one while using a fresh one on the car....no waiting.

Anyway, let me know Jeff, okay?


Tom
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Old 04-12-2010   #8
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Default Re: Off idle stumble.

PVC area may be the source but......
it's only one of many possibilities.
I have had good luck locating vacuum leaks by using a 1/4 in diameter
hose with one end to my ear and the other pointing at various suspected
leak areas. You can hear a "hiss" fairly easily.
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Old 04-12-2010   #9
Z51JEFF
 
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Default Re: Off idle stumble.

Quote:
Originally Posted by tomtom72 View Post
The tie wrap thing worked just fine till I broke down & bought the samco kit to replace all of it.

You want a NOS F-hose? I'll look up what I paid for it from chevy when they were still in stock. I bought a few for the reason you just described....they get a bit oily & they start to slip. I figured I could swap out and clean the oiled up one while using a fresh one on the car....no waiting.

Anyway, let me know Jeff, okay?


Tom
Thanks Tom,how much were these new?
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