Where exactly would one install a throttle body spacer at on a Jimmy I was told it was impossible due to the fact that the throttle body is cast into the upper plenum

 

Since you didn't provide a year, I assume you are talking about the CPI engine. You cannot use a throttle body on a CPI engine for the reason you have listed. They really don't work as advertised on the later SCFI engines either.

BTW, I moved your question into a thread of its own.

 

Yeah I agree with swartlkk, never used one myself but I've heard bad things about them, anywhere from no discernible difference to hurting performance.

 

i just recentaly purchased a TB spacer for my 04 ZR2 an after i installed it an started the truck the motor just took off an revved up to 6grand by its self an started bouncing off the rev limiter..any ideas as to why?

 

Because it was pissed at you for throwing your money into a paper weight!

Seriously though, sounds like you have a rather large vacuum leak.

 

ya it pissed me off something fierce..a friend of mine said that i might of had a leak around the throttle body its self..any truth to that?

 

It could be a leak between either the throttle body and the spacer or the spacer and the intake plenum.

Another possibility... If you removed the brackets that hold the throttle & cruise cables, you may have installed them in the incorrect order onto the front of the throttle body. The bracket that holds the ends of the cables should be installed up against the throttle body held in by the special stud/bolt, then the other bracket slips over the stud and is retained by a nut.

 

im pretty sure i put the brackets back in the right order but that could of been a possibility..i put it back to stock and it runs fine..im gonna have to wait for better weather before i tear it apart again..i started that little adventure last night as it started to snow..by the time it was all said n done we had 3inchs of snow on the ground so im just gonna hold off for awhile..lol thanks for the info