HELP: S13 SR makes fluttering noise at idle

[RebornS14.HTC]

i did a search and found a bunch of people assuming things and it was an old thread that i didnt want to dig up so i started this new one hoping people would have some new insight on my problem.

i guess im not the only one with this issue but i just got a new block built with all stock internals except aftermarket valvesprings and retainers.

since i got the car back, i noticed at idle it starts making fluttering noise after it's been running for a few seconds. i checked for vacuum leaks and found none throughout the vacuum lines.

another suggestion was that i check for a exhaust manifold leak, i checked all the nuts and they seemed to be torqued down. haven't gone down to the downpipe or elbow yet. am i in the right direction?

when i rev my car my BOV works. i have a synapse synchronic bov that's been working great. never gave me any surge before. when i press in the bov opening manually it releases pressure and the fluttering goes away but after i let go, it starts fluttering again after about 5 seconds.

the turbo was brand new less than 10k miles ago. S15 Spec R ball bearing bought brand new from performance nissan.

JUST WANT TO KNOW IF THERE IS ANYTHING ELSE I SHOULD BE CHECKING.

[BuiltS13]

I have the same problem at idle for the first little while after I start the car. I think mine is just running rich causing it to almost flood out until it warms up...I wont know for sure until I hook up AF gauge I guess or FPR

[RebornS14.HTC]

figured out the problem with some help.

my mechanics came by and did some troubleshooting.

turns out my vacuum lines were all wrong. my Synapse bov needs a set of vacuum from before the throttle body and another set after. i had them both after so it wasn't responding properly.

this of course i forgot to mention i change my intercooler piping setup not too long ago and totally missed the nipple on my previous setup on the piping which i dont have now. getting a nipple welded on tomorrow. i hope that fixes it.

my afr is fine at idle 14.3 but goes all over the place when i rev. ill post updates after the vacuum fix tomorrow.

[Mishkin_707]

I have the same problem at idle for the first little while after I start the car. I think mine is just running rich causing it to almost flood out until it warms up...I wont know for sure until I hook up AF gauge I guess or FPR



disonnect your coolant temp sensor and start it up, see what that does,