i did a compression test

[JDM 1JZ]

i came out with numbers 160, 180, 180, 160, 160, 160. i just wanted to know if that was normal i was reading on the TSRM that above 142 is cosidered good and 128 was minimum. and 15psi per cylinder for gaps. i just wanted to know what causes drops in presure like this? carbon build up? its a fresh motor. should i be worried or no. i dont know much about BHG's on supras but could this be a beginning or do i just think way to much and should shut up. hopefully i just think to much. i still have the top of the motor apart because i didnt wanna bother putting it back together til i got answers from people who know something incase i had to pull her apart. thanks guys. DrJonez says that its just carbon build up and i know hes smart just wanna get more answerssssssssss

 

[boost fiend]

dosent seem to bad. might be carbon. ya said its a fresh rebuild. did you have the head/deck milled to flatten them? how about a mhg? did ya get new valve seals? a lil more info and we can give ya a better idea

 

[supra90mkiii]

dosent seem to bad. might be carbon. ya said its a fresh rebuild. did you have the head/deck milled to flatten them? how about a mhg? did ya get new valve seals? a lil more info and we can give ya a better idea

max variation of 10% (from the highest cylinder). valve seals don't mean anything in a compression test. make sure the throttle is at WOT, and the fuel pump isn't running.

 

[JDM 1JZ]

its just a jasper drop in, i had the throttle open. i was thinking about pulling it apart and cleaning everything and mhg maybe but if its nothing to worry about maybe i'll wait til she blows