Nice link, thanks! Al I filled mine up to 6". When you balance, you want it to go down 3 inches on the unconnected side and up 3" on the connected side, that totals 6". I'm gonna order one of the manometers Larry linked to, that will be even faster

 

Another trick, compliments of yours truly, to block off the air passages, cut a piece of bicycle tubing about 2+ inches long, roll it up into a tube and stick in the passage way. Put a piece, yes, duct tape over the top to complete the seal. One set for each side. To pull the tubing out when done, just use a small needle nosed pliers.

I bought the official blocking inserts and they were useless.

 

That's funny Larry cause cause I bought the correct tool as well and oiled then as described. Well after dicking around with the TBs and went to remove the tool, one came out and the other I pulled the grab handle out of the rubber plug. So after removing the IAC and prying out the plug with a screwdriver through the hole I thought these are useless.

 

Exactly my experience. Handle pulled out of one of them. Did not think they did a good job of sealing, either.

 

Another "THREAD" added to the "sticky".....good info and thanks

 

Well I received my gauge today and decided just to check it. I had the IACs unplugged and the holes plugged. I put the hose on the front TB in the center port and it pegged the needle at -30" Can it really be that far off? And if so can it cause the surging? I ran out of time today but this is my priority for tomorrow or Sat.

 

What was the RPM when you checked? Were the holes completely closed off or was there some leakage around your plugs? The engine needs to be at operating temperature as well. Let it warm up until the thermostat opens then shut down and disconnect the IAC's and plug the holes.

 

Marc the RPM was about 450-500 in gear and the IACs were plugged. It had been running for quite awhile and was up to temp.

 

How far are the butterflies open? They should be all but closed at idle. I'm having my issues balancing mine as well, same thing, high vacuum on the balance ports. I'm researching it now. I'll let you know what I find.

 

Everything I find on the subject says either vacuum leak or tb's open too far. Block off all vacuum hoses except MAP and check around the lid of the manifold is all I can think to do. Check for a split or hole in the brake booster line as well.

 

Yea that's what I read as well. Since I have 2" bored TBs I'm just going to swap them out today and hopefully can balance them.

 

Let me know how that goes. I have a spare set that I'm thinking about sending off to be bored as well. Good luck with your balancing! I'm doing mine today as well.

 

Well I'm in the garage right now and thought I'd pass on to check your injector tower bolts to the TB. Mine were surprisingly loose. Maybe that could have count for the high vacuum as well. Just a thought...

 

Well I'm really angry now. Went through all that trouble of changing out the TB and after following the instructions I started to get the "initial air" RPM and the gauge is reading -40" of vacuum. WTF?? IACs were unplugged and the ports covered. As soon as I removed the vacuum cap from the center port on the TB I could hear the vacuum. Whats up with that and what am I doing wrong.

 

I rebuilt the tb's when I put the new injectors in, and re checked the screws for tightness this morning, but thanks for the heads up!

I think the bored tb's uncover the balance port restriction and allow full vacuum instead of the restricted vacuum we normally see. Here's what happened on my balancing experience today:

They were wayyyyy out. I was getting no vacuum out of the rear tb at all. It turned out the idle air screw was not contacting the tang on the shaft. We kept turning it in until it did, then re tried. After just a little more, we finally started seeing vacuum. But the idle was getting way up there (almost 1200 rpm). I backed off the balance screw and the idle came down without affecting the balance port on the rear tb. We got the desired 6in, then went to the front tb. Idle was still a tad high, so I backed off the balance screw again to ensure I didn't lose my water (its a pain to refill and get the bubbles out). We plugged in and got about 2 in of vacuum. Turned the screw until it was at six and set it. Rechecked the rear, and it had moved to 6 1/2 in. Rebalanced and called it good. Idle is rock steady now, no off idle stumble anymore either. So based on what you are telling me, I think the idle air screw on your tb is advanced too far. I'd back it off until you get your desired 6" of vacuum, then set the front tb as well. You don't have to worry about losing the water, so you can go with it as is instead of having to guess like I did. DISCLAIMER: I have no idea how bored TB's behave, so getting 6" may be impossible with the bored TB's. DCS claimed that if they did the boring, the balance ports acted just as they did from the factory. Others say that once bored, the balance ports can't be used to balance the tb's. Where did you get yours done?

 

I bought mine off of ebay and can't remember the name. They are nicely done but now I'm thinking if that's the case how in the heck am I going to balance them??? As of now it runs like a raped ape, no hesitation but still have my slight surging. I just looked at the stock tb where the port came into the opening, I'll have to remove the bored one to compare.

 

So based on what you are telling me, I think the idle air screw on your tb is advanced too far. So the front or the back?

 

Actually, the idle air screw on my rear tb wasn't advanced enough. I was getting 0 vacuum at first. So I advanced it until I did. Now while I was doing this, I had to back off on the balance screw on the linkage arm to keep the front tb from opening too far. Now if I had the gauge you have instead of my homemade manometer, I would have just left the balance screw alone and adjusted it once I had the initial idle air set on the rear tb. Since I was using my homemade manometer, I had to back off that screw to keep the front tb from sucking all the water out of my tube when I hooked it up. That is a step you shouldn't have to worry about because you have a gauge. I never touch the idle air screw in the front tb, because you use the balance screw on the linkage to balance the front tb with the rear tb.

Clear as mud? lol

 

Clear as mud alright, I don't understand why I'm pulling so much vacuum. I looked in the ported ones and can see the opening in the sidewall and looks to be the same. I did however have to back off the idle using the idle screw on the rear tb to get the idle to come down but did not make a difference in the vacuum. What did you use to close off your IAC ports? Did you use the useless took or do what Larry82 suggested. I was still using the tool and maybe that was part of my problem but I had them shoved all the way down in the cavity. I know when I first tried doing this on the stock tbs I couldn't hear the vacuum like on the ported ones but still pulled -30". I don't know what to do next.....

 

I used what Larry suggested, it worked pretty well. The guy at cube studio that did the write up suggested using plugs made from gardener's kneeling pads, I think those would seal better. 30" of water, I'm still thinking your butterflies are open too far. Can you take a picture of each butterfly?