Riddle me this Batman

[XfireZ51]

Got the motor put together and am battling what appears to be a vacuum leak. I first addressed what appeared to be an issue with a sticking throttle. Took primary throttle apart and cleaned off shaft of any "paint" and re-installed throttle blade. Took car out for drive and it actually didn't behave badly but idle speed was a bit high. However the "cruise control" sticking throttle seemed to be fixed. However, I still have what feels like a vacuum leak. Pulled the PCV and the 2 side ports of the plenum. In each case, idle would INCREASE when I exposed them to atmosphere.
My concern is a leak at the throttle body somewhere. It tends to raise idle from 825 commanded to a 975-1000 actual.
Here's what is interesting. when I first start the motor it will "flare" to 1500-1700rpm then idle will drop to 1000 w coolant temps at 50C.
As coolant temp increase I can see the IAC counts drop and so does the idle rpm. OK, so now the motor is idling at about 850 or so with IAC counts of ~ 10. GREAT except then I blip the throttle. IaC counts drop to 0 and now idle has a bit if a surge at about 900-1000. Otherwise the car drives well with no surging at PT cruise. So why does blipping the throttle
upset the apple cart?? Any suggestions before I pull the plenum are appreciated.:cry:

[John Boothby]

Just a guess, but did you check your TPS?

[XfireZ51]

Just a guess, but did you check your TPS?

.55v. I put a scantool on it, yes.

[rhipsher]

Dom after I had my top end powdercoated and put it back together I had a high idle problem. And when id blip the gas peddle the idle would drop back down to normal 900. This is a vid I made of the problem and how I fixed it.
http://static.photobucket.com/player.swf?file=http://vid301.photobucket.com/albums/nn63/keeno1970/2010-12-07_20-04-26_724.mp4
Im not saying this is the cause of your problem but its worth taking a look at.

[XfireZ51]

Dom after I had my top end powdercoated and put it back together I had a high idle problem. And when id blip the gas peddle the idle would drop back down to normal 900. This is a vid I made of the problem and how I fixed it.
http://static.photobucket.com/player.swf?file=http://vid301.photobucket.com/albums/nn63/keeno1970/2010-12-07_20-04-26_724.mp4
Im not saying this is the cause of your problem but its worth taking a look at.

Would love to see vid. Link not working.

[RICHARD TILL]

try again. i just watched it.

[scottfab]

Video worked for me. Well done.
I have not seen sticking there before but will keep it in mind.
What I have seen on two TBs is the big two sticking.

[rhipsher]

Were you able to veiw the vid Dom? I don't know how else to get it to where you can veiw it. But in a nutshell the little lever outside the TB housing on the drivers side that opens the primary throttle plate was sticking open from lack of lubrication. Hitting it with brake clean and then white lithium made it operate smoothly.

[GOLDCYLON]

Dom I could send you back your old TB you sold me a year ago to test out your TB theory. Its just sitting in the parts crib. LMK Daryll

[GOLDCYLON]

Were you able to veiw the vid Dom? I don't know how else to get it to where you can veiw it. But in a nutshell the little lever outside the TB housing on the drivers side that opens the primary throttle plate was sticking open from lack of lubrication. Hitting it with brake clean and then white lithium made it operate smoothly.


Good video. Last time I had a simular problem the IAC valve on the oposite side had seperated inside the side of the AH. The spring and the check valve had seperated from the valve body and were sucked into the side of the AH. Just another possibility.

[XfireZ51]

I have R&Rd the TB about 8 times. Its clearly a throttle plate issue and how they are positioned in the bore. Overall the motor is very responsive and feels very strong. But I am dealing w a sticking throttle when I depress pedal past 3k rpm. a stab of the pedal puts things right but...
I'll try rhipsher's approach before I leave it up to Marc H to re-assemble the TB properly. However, when the throttle hasn't stuck, idle is very smooth at 800-850. The cam lope feels more pronounced than before.
Throttle response is great. Not soggy at all.