vacuum leak

04oxfordvert

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so my car idles rough at best when it has 15 in hg. then will drop to 10 and slowly stumble then die. cannot find leak in engine bay. this is all stipped at an idle. the crazy thing is while at cruising 60mph and close theottle completly it will jump to 20-22 in hg. im totally stumped. any ideas. checked pcv all is good and all lines in engine bay are good..

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Bdubbs

u even lift bro?
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Hopefully it's not the pcv hose in the lower intake. I'm kicking myself for not at minimum putting a hose clamp on that hose when I swapped blowers.

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04oxfordvert

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im pretty sure its not that as i pulled the pcv out and there was major vacuum there. so im kinda ruling that out. and i was affraid of that aswell. lol
Hopefully it's not the pcv hose in the lower intake. I'm kicking myself for not at minimum putting a hose clamp on that hose when I swapped blowers.

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01yellercobra

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What throttlebody are you running? Does it happen all the time or only at certain temps? Such as cold start or when the engine is fully warmed up.
 

04oxfordvert

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i have a 2.3l tvs gt500 tb setup. doesnt matter cold or hot. and it just started doin this in past 2 days. have driven all summer no issue.
What throttlebody are you running? Does it happen all the time or only at certain temps? Such as cold start or when the engine is fully warmed up.

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hotcobra03

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Intercooler housing gasket also.

Strange some have said they don’t have a gasket in another thread
 

hotcobra03

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Google the link.
It brings you back to svt here. You want the second pdf.

03cobra vacuum hoses documented

Is a pdf file. Shows all lines with color pics
 

04oxfordvert

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it appears from that diagram that the hose in the fender goes to an evap vale mounted in the inner fender. im gonna see if i can get at it. as i have zero tools as im moving accross the country. lol but that could prob have an effect on low vacuum and possibly a fueling issue?

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hotcobra03

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it appears from that diagram that the hose in the fender goes to an evap vale mounted in the inner fender. im gonna see if i can get at it. as i have zero tools as im moving accross the country. lol but that could prob have an effect on low vacuum and possibly a fueling issue?

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Fender well cover needs to be pulled down.

Has plastic push pins

And screws on rocker panel corner

Where is your gauge attached

There isn’t really much vacuum on this car

And with the huffing and puffing I can see a gauge do strange things
 

hotcobra03

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That lower intake hose is the biggest hose of the system.

I did clamp my hose after seeing
171/174
Hose got hard and wouldn’t pull off nipple yet it would spin on nipple which was a major vacuum leak

It’s like the evap. Hose that makes your hand black and not come off.

Items that should be replaced with new fuel line hose
 

04oxfordvert

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ya i seen that thats where it is. my guage is attached on a tee behind the glove box on the yellow hose.
Fender well cover needs to be pulled down.

Has plastic push pins

And screws on rocker panel corner

Where is your gauge attached

There isn’t really much vacuum on this car

And with the huffing and puffing I can see a gauge do strange things

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04oxfordvert

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ya ive verified that hose is good as pulling the pcv out there was major vacuum. ive ruled out that and the hvac lines. the evap and vlack hose that gets you black are only 2 left to verify.
That lower intake hose is the biggest hose of the system.

I did clamp my hose after seeing
171/174
Hose got hard and wouldn’t pull off nipple yet it would spin on nipple which was a major vacuum leak

It’s like the evap. Hose that makes your hand black and not come off.

Items that should be replaced with new fuel line hose

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hotcobra03

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ya ive verified that hose is good as pulling the pcv out there was major vacuum. ive ruled out that and the hvac lines. the evap and vlack hose that gets you black are only 2 left to verify.

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You can’t rule out lower intake hose with out removing lower intake for hands on nipple in face

Actually it’s always good to clean intercooler

It only takes a few minutes to pull blower and intake
 

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