manifold intake FLAPPER and Lean question

[Ken Potter]

What is the valve ( flapper) called on the intake manafold. I think this flapper opens on some command (?) maybe WOT to increase intake air true? How long does it take this valve to open? Can this flapper be opened manually to stay open all the time and will it still run ok if done. This is a race car application with stock pcm.
Also I think my motor runs lean being twice now I looked at my new plugs after just one race night and they look very very clean and the tip looks hot. What can I look into to determine a lean condition when there is no codes? How can I easlely give it more fuel duration. Yes there stock injectors.
Is there more than one water temp sensor? When I have the water temp senser unhooked ( over thermistat housing) the water temp gauge inside the car still responds to changing temps? How can this be with the sensor unhooked?

[nlsolja123]

are you talking about the svt manifold?

[david gettle]

I don't know what you mean by intake flapper, but both the ZX2 and Zetech powered Focus use the same thermostat housing (even though they are diffrent part #'s), two coolant temp sensors, one for the PCM, one for the dash guages. unhooking the one for the PCM is not recomended.

[Ken Potter]

HI Dave,
Thanks for the reply Dave so there is two water sensors, thanks. Can you tell me Dave why it is not a wise idea to unhook the water sensor the pcm uses. When its unhooked, the fan runs all the time, which it does anways during racing, so no harm there. What I was woundering about origionally is with this sensor unhooked, would the pcm give more or less fuel to the motor Vs a hooked up sensor reading 180deg. I can also place a new water temp sensor wired up so it does have realible info back to the pcm but with the sensor not installed in the pipe but rather just free air. This should tell the pcm the water is still cold and its ok to give more fuel and more timing advancment. Im just thinking out of the box here with no knowledge at all on dynos but dont it make sence it would increase my fuel duration and increase my timing advancment telling the pcm the water is always ambient ( maybe 100deg.or so) ( Race application here) Im lean now by looking at two new sets of plugs after just one race, porciline very very white and the tip very clean and hot looking. The majority of the time this motor is turning 4-6500 rpm or its not running at all so those plugs are under that condition.

[JohnP]

Flapper valve , must be thinking of the IAC(idle air control)adjust idle with engine load .Theres a backfire valve on the bottom side of the plenum . Plugs sound fine for what your doing , not blistered ,melted or metal transfered onto the porcelain . To increase your fuel duration , you have to change the pulse width of the injector , need to chip it so it's in the PCM . Could do a pots mod for temporary use .

[mechtech]

What is the subject here?

[Ken Potter]

hi Mechtech,
Yes the post is kind of going off track and its problemy my fault. I ask a question first that im thinking of for a problem/concern I have. I will try to explain.
My xz2 is for racing oval track. I check my new plugs after each race ( 2 now) and both times I notice the plugs are very very clean and still very white on the porcline and the tip looks hot. When we race its about 4k rpm to 6500 rpm. I was thinking as long as the plug looks so so clean and hot I could use some more fuel duration. With that said I will continue below.
If the pcm uses the water temp sensor as part of its inputs to alter the duration and that duration would be longer if the water temp reading was colder then why not fake out the pcm. When you unhook the water temp sensor the cooling fan runs continualy, which is ok cus during racing it runs anways. My question was with this sensor unhooked what now is the duration of the injectors, longer or shorter in compairison to a sensor that reads 180 degs? We know it still runs right, and we know it still has a durations figure of somthing so all im asking is, is that duration more or less?
I could also take a new water temp sensor and hook it up dangeling under the hood without it installed in the thermistat and tell the computer the water temp is about 100 deg but then I will also have to wire up my fan on a switch.

[iceracer]

I'm still curious about that flapper valve.

[pure]

With the sensor unhooked the car will never come out of open loop .. meaning it WILL run richer , how much richer? I'm not too sure. All you are trying to do is increase the duty cycle of the injectors. I would suggest SCT , getting a tune on it will not only help your fuel issue but will probably get a little bit more power out of her.

[mechtech]

Plug reading is an art. You don't look at the tip for mixture, you look for an annular ring of color near the base of the insulator. The tip just shows if the plug is hot enough to burn the mixture off and stay clean.
Modern gasoline doesn't leave easy to read deposits anymore.

In other words, your plugs readings show nothing except that they are not fouled.

If the car computer/tuning is stock and not tuned, there is common POTs modification that can be used for more ignition advance and make it a bit richer. It's the advance that helps a lot. This fools the computer into thinking the engine is cold, and give you more timing advance.

[pure]

This fools the computer into thinking the engine is cold, and give you more timing advance.

Thats what your looking for .. if your only need is that then do POTS if you want more specially with the future insight get SCT.