iluvmy86

iTrader: (1)

alright guys i need some words of wisdom. i have a stock s4 t2 with a fresh rebuild. i just rolled past 500 miles on the car and have done my first oil change already. but lately i have been having this on going problem of my car have a "hesitation". this happens on and off from idel to about 3k when i shift. now when there is this hesitation i would be under load the there would just be no power and then it would lick it the hesitate some more. i also have noticed the the boost gauge is dead 0 while the car is "hesitating". this problem will happen for a little bit and then eventually go away and i can see the boost guage working again after maybe driving a couple of miles.

so far i have checked for any vacume leaks and there are none. i have even replaced the TPS and that wasnt it either. but i dont think it could be a mechanical problem so i am assuming its electrical. I am almost going to guess that maybe i should replace the stock boost sensor. but please help.... its so hard driving like this and im tired of people honking at me for my car stuttering.

Syonyk

Did you replace the stock line from the intake manifold to the boost sensor (or is it a pressure sensor on the turbos?) with a straight replacement? The stock one has a tiny restrictor orifice in it, and if it's missing, the strong vacuum pulses will make it through to the sensor and confuse it. I'm not 100% sure what issues this will cause, but I know it causes problems.

Also, take a voltmeter and check the boost sensor - the FSM has directions on what to look for voltage/resistance-wise. The boost gauge sitting at 0 is a strong indicator that something's wrong in the boost sensing circuits, so you should start troubleshooting there.

-=Russ=-

micah

Does anybody know if the orifice thing is just an S4 thing or if it applies to S5 as well... I'm doing an engine swap as well and would like to replace the vacuum line on my pressure sensor.</hijack>

iluvmy86

iTrader: (1)

i did replace the line that goes from the boost sensor to the manifold with just a normal vacume line. i will try getting ahold of a stock line to see if that will help.

micah

There was talk a little while ago about making your own orifice with epoxy and a really small needle.

https://www.rx7club.com/showpost.php...0&postcount=13

Check that post.. HAILERS knows all.

iluvmy86

iTrader: (1)

ill check that out. thanks!