Bypassing Double Throttle
 

I broke off the nipple to the Double Throttle solenoid when removing the check valve, so I decided to just bypass the double throttle.

I took out the check valve and capped that vacuum line that went into the intake manifold. I then pulled off the hose from the nipple above the nipple I broke on the solenoid, and capped that line going into the intake manifold.

Then, I saw that the actuator was still putting force on the throttle plates, so I removed the actuator.

My question is: 1) Are there any more hoses going to the Double Throttle solenoid that need to be capped?
2) Can I leave the Double Throttle plates just sitting there with no pressure on them? Or do I need to wire them open? It seems that the air would just force them open, since there is no force keeping them closed.

Thanks,
Adam

PULL the plates out for better flow . I would have the shaft removed also . Just leave the electrical parts pluged in if the computor needs to know they are there .

Why does the FD have double throttle plates anyway??

Wire them open at a minimum. Remove them if you are sure you'll never want them back (and you want a bigger project).

After looking at it further, I have two questions.

1) Does the vacuum hose behind the Solenoid need to be removed? It shows up as nipple "C" in the FSM. Right now I just have nipples "A" and "B" open.

2) Which position is the plates to be wires open in? Does the Actuator pull the plates closed, or does it pull the plates open?

Thanks,
Adam

the double throttle allows your car to warm up properly before heavy driving. be sure!! that if you remove/bypass the double throttle, that you warm your car up properly. I broke nipple c but am replacing to start with a good running unit before any modding to the vaccum system.

As per the factory manual:

The Double throttle plates prevent the engine from going into a momentarily lean condition when begining to boost. The basically let boost to slowly build up in the engine as opposed to letting it all rush in at once. Not exactly reliable, but I checked my o2 readings when I pulled them out, and they never even dropped below .85v. Now with the PFC, it never even drops below .90v.

I can tell you when I removed mine, I certainly felt the differance.

Actually, doesn't the actuator pull the lever (vacuum applied, when solenoid activated) to close the secondary valve? If so, then simply removing vacuum from the actuator would leave the secondary valve open all the time, thus never restricting flow through the secondary inlet. And this does not require wiring open the valve (or even disassembling anything related to the extension manifold or TBs).

I actually did this on mine, and it made a noticeable difference, in that it seems that boost comes on more strongly and consistently (watching the gauge, anyways) - I would assume that is attributable to no sudden increase in flow capacity when the secondary valve would normally open. All that I did was to remove the vacuum hose from the nipple (the exact one that n/arotary broke). I didn't even bother to close off the vacuum hose, but rather just let the check valve hang there (yeah, I know, but it is only leaking when the manifold is in vacuum - the leak hasn't even made for a noticeable difference).

Please, correct me if I'm wrong...

Re: Bypassing Double Throttle
 

The three hoses going to the DTCS solenoid are as follows:

1) Atmosphere line, with filter at end.
2) Vacuum source line, through check valve to extension manifold.
3) Line to DTCS actuator.

You obviously don't have to do anything with #1 - this is the hose that connects to the "back" of the solenoid, that is, the nipple on the side that only has one nipple.

Technically, you would want to cap off the line from #2 to the manifold, on the manifold side - just disconnect the check valve from the line to the manifold, and plug that line - this will prevent vacuum leak from the manifold.

And then you don't have to do anything with #3 - you can just leave it connected to the solenoid. Or, in your case, you have removed the actuator altogether, and as a result, this line.

I broke the nipple too. About a year ago. I just capped the line on the front of the manifold, and the line on the back, so there are no vacuum leaks. The car runs just fine.

Adam (also)

pull the plates out completely, and plug the hole with a set screw/ I had to thread the hole first

You can, but you don't have to bother with removing the plates if you don't want to, because by simply not applying vacuum to the DTCS actuator, the plates will never be closed (they will always be in the open position). To accomplish this, you simply have to disconnect a single vacuum line from the DTCS solenoid and plug that line.

The resistance created by these plates when in the open position is minimal. Removing them would only serve to simplify the intake system, and rid the car of a few ounces.

I ended up taking off the actuator system, so I had to do something with the throttle plates. The only good way I could find of keeping them closed is with electrical tape.

Whenever I take my UIM off for replacing vacuum hoses, I am going to remove the throttle plates then.

You don't want them closed, you want them open!

I mistyped. I meant open:)

Oh yeah, if you remove the actuator, then the plates become even more useless... Then I could see removing them altogether! Especially if you happen to have the extension manifold off the engine...

Just use a shotgun...........

BANG !

BANG!

voila u got a ported UIM with no butta flies..

yeah, I just plugged the line, capped the actuator and went on my merry way.
Yes, I too noticed a difference at WOT.
I figure Ill have to open up the TB again soon and Ill just take the butterflys out then.
Thanks to Mr.Ouija for the input.

Is Mr. Ouija the one who controls double throttle on these things? :p: