Mods... and junk

[spazegun2213]

ok, So the TBS and the intake are on. The check engine light is still on (its a little annoying) but that will come later.

First, if you have ever driven a big truck you will understand this, the throttle is jumpy, like on just the littliest foot input (at the start) you get a ton of gas. so I'm finding I'm slipping the clutch longer and my lunches are getting really poor. I think this is becuase the TBS raises the TB and the TB cable is looser than it was before. So Solution? i noticed its easily attached to the gas pedal, so i think I'll make a spacer for it. Also, since i had the TB machined should i grease around the spring area? This might be binding creating that large input from a start. What do you think?

Second, What is the piping running from the valve cover to the air intake? I'm getting new piping for it in an attempt to get it straight again. Its currently bent....

Third, In my attempt to see how the throttle cable was attached to the pedal i noted that it would be REALLY easy to fab a new arm so that all the pedals are even. However, if i did that then i would need to move the seat back further and its already all the way back. Has anyone moved the pedals or their stock seat before? I cant buy another seat... no money so what are my options?

thanks

 

[Dr. Dyno]

When you install a 1" thick TBS, you also need to raise the throttle cable bracket 1" off the manifold by using three cylindrical spacers and longer bolts. That solves the problem of the throttle cable angle.
Your other problem could be that the throttle plate is binding on the bore so that when you press the throttle, there's initially nothing and then it suddenly lurches forwards. If that's what's happening, you might need to lightly sand the edges of the throttle plate so that there are no sharp areas that'll "stick" to the bore.
The pipe running from the air intake to the valve cover is the crankcase breather pipe. The vacuum from the crankcase should suck in clean filtered air.

 

[spazegun2213]

do you have a pic for those spacers? i have them, but there were not intsructions on how/where to put them.

 

[Mike@Accurate]

Most 4.0's have 3 bolts holding the throttle linkage bracket to the intake manifold (new ones have 2). You need 3 tubular spacers and 3 longer bolts. You put the spacers under the bracket and bolt it down with the longer bolts. Now the throttle cables will line-up with the TB again. The tube to the front valve cover grommet is air going in for PCV. The one going to the back is vacuum going out. The one in the back is specific size and is called the orifice tube. Change this one and you will change idle speed (if the IAC can't keep up). Good luck, MIKE

 

[spazegun2213]

Sorry, I'm fairly new to all this, so i really dont know what your talking about, when it comes to the TB. I think i pic would be helpful so i can see what you are talking about. As for the Intake piping. I have a '98 so there is only one tube comming off the intake.

Also, how do you find out the error code on a jeep? I have tried turning the ignition on, off, on off, on and nothing heppened. So should i just have someone check it for me?

thanks

 

[Mike@Accurate]

"I think this is becuase the TBS raises the TB and the TB cable is looser than it was before. So Solution? i noticed its easily attached to the gas pedal, so i think I'll make a spacer for it. Also, since i had the TB machined should i grease around the spring area?"
Odd
TB="Throttle Body"
"Machined"=Bored?
If so, this is what changed your off-idle throttle response. Once you bore out the "hump", you move alot more air at low throttle opening. MIKE

 

[spazegun2213]

yes, it is now 62mm, but that throttle jump is more than the TB being bored, its a BIG jump. I found instructions on how to install the throttle linkage spacers and will do that tomarrow.

So what about the pedals? anyone ever tried to level them out? I know they are offset for a reason... but still.

 

[spazegun2213]

So the spacers for the throttle linkage bracket fixed the jump, but there is still an issue of a whistle from about 2500 to 2700 rpm under 1/2 throttle. I dont think its the intake, but i dont think its the gaskets for the TBS either. So I'm out of luck. its getting really annoying especially on the highway.

 

[Dr. Dyno]

If there's no air leak from the TB gaskets, the whistling is being caused by one or both of the following:

1. The helix spiral. Removing it will reduce the whistle but not eliminate it altogether.

2. Air rushing past the idle air bypass hole above the throttle blade. That's the most likely reason and the only way to reduce it is to grind away some material at the lower edge to round it off. The whistle is caused by air hitting that sharp edge which produces turbulence.

 

[spazegun2213]

maybe i should have checked here before i started a new post. oh well, anyway the TB plate is not to the correct measurements (there is a gap in the plate) and i think/hope thats it. I'll have my friend remill me a new plate if i can find plate specs. I'll also see if there are any sharp edge's that might be causing it.

Edit: there is no helix in the TBS.