plug the pvc hole abd breather hole and spray carb cleaner in the oil fill hole? and see if the idle goes up

 

Mkos,

Just plug the breather tube or opening and let the PCV evacuate the case. The idle should slowly get lower, and you should build an impressive vacuum in the case. If you think there is an internal leak on the underside of the intake, remove the PCV and plug the openings. Make up an adapter to insert a vacuum gauge in either the breather or PCV opening, and monitor vacuum readings. There should be none, and will more likely be a little pressure increase from blowby gasses.

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Later,
Vader
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"I'm'a do Things My Way - It's My way or the Highway."
Adobe Acrobat Reader

 

Heres my whole problem. I put a new intake on, runners, and new TB. When I started up the car the idle was at 550 and thats with an ice cold engine. As it warmed up I tried to give it gas and if i just hit the petal it sounded like it would want to die. But if i gradually gave it gas it stumbled around 1000 RPMs then shoot up and sound nice. Once warmed up the idle was about 1400 and would go any lower. I turned off car grounded it and 30 secs later disconnected IAC. Then the car wouldnt start at all. The idle screw was set too low so I moved it up to where the idle was 550 disconnected. I then turned off car and connected IAC. started it back up and the idle was at 1600. I dont know if I have a vacume leak. i went around engine with carb cleaner and couldnt find a leak. O2 readings are 30-850, and the IAC says 1600 with a level of 64 on my scanner. I asked my neighbor who is a GM tech about the problem and he said possible still a vacume leak. i am not burning any oil or coolant. I hope someone can help me.

 

If your IAC counts are that high, I'd say it's not a vacuum leak. On my 2.5 (IAC operates pretty much the same) the IAC counts were zero, and I found that the minmum idle speed was too high (pretty much the same as a vacuum leak.) In other words, the IAC counts will typically be low when it is trying to compensate for a vacuum leak.

Could you maybe running rich? Maybe it is seeing the rich condition, and can't narrow the pulse width enough, and it is giving it more air to make up for it?

Too bad you live so far north from here, I'd offer to give you help!

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Working on:
'84 Z28 LG4 305 with 200,000 original miles!
Added dual elec fans.
145 MPH IROC Speedo
Building 430 HP 350 (ZZ430)
using primarily GMPP parts.
Short block sitting on a stand.

Starting to look like the Kicker poster child!

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