75MM TB and Plenum install

JerZeyStangz · May 24, 2014

Who here has installed these items on there 96-98 GT? I had to do some research because I bought my throttle body and plenum used. I found out that I have a MAC throttle body with a idle screw next to the tps, I've noticed on other style throttle bodies this screw is not present. Is this a advantage for me from tuning stand point? I also got a c&l plenum which is my favorite out of all the plenums and the cast is actually really smooth inside on the inside of the plenum. What are some tips for a trouble free install on my car? Two things I am really concerned about its the idle screw, and the throttle stop on the throttle body, both are adjustable and I have no idea where they should be....

joekd · May 24, 2014

You are worrying over nothing. Just install, start car, let run for a minute, adjust idle only if far too high or low, done.

Ferocious · May 24, 2014

Agreed ^

Just take the old one off and put the new one in. Not much can go wrong. I have a MAC t/b on mine and the set screw really doesn't do anything unless you need it to idle higher than it should. I have mine set all the way back, with the throttle stop barely touching the screw and my car idles perfectly at around 600 rpms.

JerZeyStangz · May 24, 2014

joekd said:
You are worrying over nothing. Just install, start car, let run for a minute, adjust idle only if far too high or low, done.

Thanks I will do that. I was actually looking at your old thread about your tb/plenum install.

Ferocious said:
Agreed ^

Just take the old one off and put the new one in. Not much can go wrong. I have a MAC t/b on mine and the set screw really doesn't do anything unless you need it to idle higher than it should. I have mine set all the way back, with the throttle stop barely touching the screw and my car idles perfectly at around 600 rpms.

Can I see a picture with the "gold" screw set all the way back? Mine is in the 2 o'clock position.

Do we have to check the volts at the TPS, or is just self adjusting? When I researching, the 5.0's have tps changes by turning the TPS in a clockwise position and tightening the tps screws down.

Ferocious · May 24, 2014

JerZeyStangz said:
Can I see a picture with the "gold" screw set all the way back? Mine is in the 2 o'clock position.

The set screw is already set all the way back in a way. Any more and there will just be a gap there. The throttle body lever will not go any further back then the position it is now, it will only go forward.

Do we have to check the volts at the TPS, or is just self adjusting? When I researching, the 5.0's have tps changes by turning the TPS in a clockwise position and tightening the tps screws down.

You can always check your TPS, but there is no way of adjusting it yourself. TPS adjustment is a myth.

http://www.stangnet.com/mustang-forums/threads/adjusting-your-tps-to-0-98v-is-not-necessary.825424/
http://mustangforums.com/forum/5-0l-1979-1995-mustang/306203-tps-voltage.html

Adjusting your TPS to .99999999 volts is not necessary at all. There is a general range the computer will accept as idle voltage for the TPS. This range is 0.5 - 1.1 volts. ANYTHING within this range is acceptable. If idle voltage is outside this range, a TPS code is generated by the computer.

Therefore, the only adjustment really necessary is to verify the tps voltage at idle is anywhere between the above range. If this is a FORD OEM tps, it should be. Aftermarket TPS's might be different and require you to slot the holes to get it in range. If it is in range, then you are fine. No need to chase the mythical 0.99 volts that has been tossed around for years. Upon vehicle startup, the computer will take the base idle voltage, and apply 2.71v to that number as the trigger point for WOT operations.

JerZeyStangz · May 25, 2014

I took this picture.The throttle stop is perfectly adjusted like yours in your picture where it barely touches the throttle cable mechanism. The gold screw I am talking about is the flathead screw in my picture thats in the 2 o'clock position.

JerZeyStangz · May 25, 2014

Hey Ferocious, can you provide info on the gold flathead screw bolted to the housing of the TPS, does it do anything at all?

Wichers123 · May 25, 2014

It's a idle bleed don't mess with it. Also the throttle stop screw make sure the blade is not digging into the throat.

Ferocious · May 25, 2014

JerZeyStangz said:
Hey Ferocious, can you provide info on the gold flathead screw bolted to the housing of the TPS, does it do anything at all?

I don't think that's what you use to adjust the idle? To "adjust" (which you can't really do) the tps you tighten the set screws on top of the tps sensor last time I checked: http://www.muscularmustangs.com/tps.php

And here's a picture of my throttle body that I just took 5 minutes ago to show you the screw on mine like you asked. Looks like it sits perfectly horizontal.

JerZeyStangz · May 26, 2014

Wichers123 said:
It's a idle bleed don't mess with it. Also the throttle stop screw make sure the blade is not digging into the throat.

"

I will not touch it. What does the "idle bleed" screw does anyway? I will make sure that the throttle stop screw doesn't let the blade dig into the throat like you said.

Ferocious said:
I don't think that's what you use to adjust the idle? To "adjust" (which you can't really do) the tps you tighten the set screws on top of the tps sensor last time I checked: http://www.muscularmustangs.com/tps.php

And here's a picture of my throttle body that I just took 5 minutes ago to show you the screw on mine like you asked. Looks like it sits perfectly horizontal.