Hi all, just checked the injectors on my vehicle and while messing about i seen that the throttle bodies dont seem to open all the way. looks like 95% fully open? i took some pics of them closed and open, is this the way they should be or can i open them some more? if so how would i do that??

 

Closed

 

 

Fully Open

 

 

Regards Andy

Really you need to see the butterfly in the throttle body to see if its opening fully, it should be straight and the same on left and right.

As above, but if they both open the same, but not 100%, there is a stopper in the middle, which can be easily fettled to allow them to open slightly more, mine didn't open 100% so I just bent it ever so slightly and now they do, but needed to very slightly adjust the throttle cable too, easy job tho, I'll see if I can find some pics...

hi guys, had a look on vehicle and when throttle is open i can still move the butterfly valve about 5mm so doesnt look like they opening fully. do i adjust the screw (as in last picture above) so it pushes it open more. but by doing that wont it stay open when closed?

Quote from another site in case its of any help ...

 

"Hey Folks,

 

At our last Tampa Z meet, a bud pointed out that when we open

the throttle, a tab on the connecting shaft butts against a stop,

keeping the butterfly valves from opening all the way.

 

He had heard the reason for this was that it was Nissans way of keeping HP

within limits ... lawyers, federal regs, insurance, and such.

 

A careful look confirms that there's another 5 - 7 degrees to go

before the throttle is truly at full open!

 

 

Actually, at least on my 93, there is an adjusting screw/stop at

the linkage of the left/right connecting rods. That adjusts balance

between the banks. But the tab which restricts the overall throw

of the connecting rod/butterflies has no adjustment screw. Equally,

there is no adjustment on the stop. It's just a stump of the aluminum cast.

 

(FYI the earlier cars have an adjustment screw stop in this location.)

 

Step on the gas, and the cable rotates the connecting rod until

that bare tab(ear) coming off the rod smacks into the stump of aluminum on the plenum.

 

To all TT folks, take careful notice as to just how far away from

parallel our butterflies are stopped!!

No, do not modifiy the throttle to open fully!

 

This is a well known misbelieved "modification", but the reason the throttle does not open with butterfly valve fully horizontal is because of the angle of the intake pipes into the throttle bodies. The throttle valve is designed to sit at the same angle as the upward angled intake pipes.

 

The stock throttle opening angle provides max flow, and opening it up fully will only restrict flow.

 

There is a before and after dyno comparison with this "mod' and the car lost power with the throttle opening further.

Edited September 3, 200916 yr by Yowser

thanks legrath thats great, ill check to make sure the angle is the same as the pipes.

I'm one of the mis-believers then ;-) Will fettle it back tomorrow, hahaha....