my 87tII will boost like a light switch, sometimes cruising i'll gas it and it will run like my na other times it will boost instantly and redline right now,off /on off/on. new engine idles perfect starts normall. 2 1/2 dp, 2 1/2 mp bonez intake stock y pipe and mufflers.whats really weird is when im not geeting boost i'll fan the clutch like on a dirt bike and it'll get full boost like something stuck or clogged then it frees it self up. any help would be apprciated thanks

 

check your waste gate lines, also your turbo maybe going bad....take off the TID and check compressor play....

 

does your on/off boost have HESITATION in between?
it could be fuel cut...

-mike