low vac, not boost leak

[Diceman19]

can anyone think of any reasons for low vac besides boost leak? i am getting about -15 to -17 on the vac and my car idles badly. car almost all the way stock, just stopped boosting one day and then started idling bad and dropping idle low erratically. i have checked for boost leaks, i have none. pcv valve replaced, checked plugs, wires, coil pack, MAF, and CAS. compression on motor is awesome. fuel pressure is ok because car is running pig rich. any ideas? ecu is the next to get checked but the car only has 55k on it all original so the ecu looks brand stinkin new. thanks!

 

[adam355]

Valve timing off?

 

[Diceman19]

dont think so but that is getting checked this weekend as i am pulling out the timing belt to see if i can find this new bad sounding noise that it starting making last week. keep in mind i havent been driving it and i start it to drain the gas and it starts making this rubber/plastic/whatever else is making the noise type noise. just loud and not good. def not drivable in that condition, regardless of the vac readings and idling being crappy. but like i said, dont think so.

 

[1993eclipseGS]

That is how much vaccume you should be getting. The car doesnt boost at all, And you checked for any boost leak? Did you check the wastegate arm to make sure it didnt come off of the turbine housing? When my car was running really rich, Spool up was really slow, I had to lean it out, Why is your car running super rich? If your idle is low, Did you adjust the Biss?

 

[BigBADGSX]

I remember one time i was out for a little back country driving, and noticed my car was having one hell of a time boosting. So i stopped to check some things out and noticed the vac line to my fuel pressure regulator was off. Made my car feel like a complete DOG. Just make sure you check all of your vac lines

http://www.taboospeedshop.com/emissions1.htm

 

[Diceman19]

the reason i say my vac is low is because it was -20 to -22 before this idle business started. i will double check the wastegate arm but i installed an exhaust and remember looking at the arm already. my guess is as good as yours as to why the car is running so rich. i have not adjusted the BISS because the idle is not high, but erratic. the timing stuff is coming out tomorrow morning so i will know if it was a timing issue early afternoon tomorrow.

EDIT, this is on a 1g BTW, the link you sent for emissions is for 2g. i have checked the vac lines too, didnt see or hear anything out of the ordinary but those are getting removed this winter if i still cant figure out the idle issue. divide and conquer IMO. i also dont have any fuel controllers or fuel mods for that matter so i cant adjust any of that. if i can find an eprom ecu, i have the dsmlink sittin on my bed as we speak. im sure the datalogger will help me in my quest. but im putting the cart before the horse. me needs an eprom first.

 

[InjenTalon96]

are u venting ur bov???

 

[1993eclipseGS]

If your idle is erattic and goes everywhere, Try pulling up on the cruise cables, or messing with them, mine will idle surge if I do that for some reason, When it is cold.. And i tug on them, It will stop.

 

[my_gst95]

Does the vaccum improve after driving awhile or after the car warms up? I have the same issue on my 90 and I've narrowed it down to the FIAV. Car starts in the morning at -15, vaccum leaks through the seals until its warmed up after 10mins of driving, then vaccum is back to -20.

my_gst95

 

[Diceman19]

no, i am not venting, and no, it does not get better when the car warms up, it just dies because it dips low enough to kill it. :-(