Cracked throttle body

[97gpl36]

Hey guys,I was wondering if anyone ever experienced a cracked TB.My ltft likes to hang around 16 at idle,still can't find any external vac leaks.Almost 10,000 miles on rebuilt engine with metal lim gaskets and new uim.I've heard of the TB developing cracks at the "Y" fitting in some of the forums but I'm still unsure as to where that fitting is located,also wondering if throttle plate shaft could be leaking vacuum.No rpm change when checking with tb cleaner.

[Hippo Machine]

Haven't heard of cracked tb on these cars. Maybe check something obvious, mine did this when I hadn't secured the air filter area correctly to the cleaner box.

[Z34Phoenix]

do you have the screen on the TB? do you have a tuned pcm? injector orings?

[matt5112]

the y fitting comes off the TB nipple.

it is rubber so it can dry rot and cause a vacuum leak.

[97gpl36]

Thanks for the replies and guidance,my TB screen is in place and injector O rings were replaced again after having them cleaned,I paid a chevy dealership employee to tune my PCM,but still unsure if they were capable of comprehending the comp cam,105# springs and ported LIM and heads mods.As for the "Y" fitting being connected to a nipple on the Tb,I can only guess that it must be one of the two vacuum ports facing the front of the car,if so,all of that stuff has been replaced with new rubber and plastic.still doesn't change engine tone with TB cleaner or starting fluid for that matter.I was told by a local mechanic that there are valvetrain issues after a vacuum gauge shown mild fluctuation at idle with 15 HG.Planning to let Paul in Dallas,GA sort it out when funds become available,he is a specialist with the 3800 engines.

[Z34Phoenix]

Umm a dealer can not tune these cars for aftermarket parts. They can reflag a stock file but the is it. So if you are running a cam springs and ported LIM the it is no wonder your trims are so far off. Also a cam will effect vac at idle too. I seriously doubt you have any issues with he tb. You just need a tune.