So confused. Turbo, pvc system, rings?

[89supra7mgte]

my car at idle runs about 14 in of vac (vac is measured in inches not psi) just so you dont get confused on that. And i believe when i come off throttle on decel it is around 18-20 then drops back 14 or so.

I good strong engine should be 12 plus iirc. someone please input corrections to this post if needed

 

[7M-KDL]

Well actually now that you mention it I think my gauge reads in inHg

 

[89supra7mgte]

i believe on that guage you will see i higher number being mm instead of in. might have to do the conversion

 

[7M-KDL]

I went and double checked it is inches. Reads like 16 to18 at cruise and starts smoking at 26 on decel

 

[89supra7mgte]

if you are doing the compression test this weekend, then check all your vacuum lines in the mean time, see where and if you are getting oil or something in them.

 

[7M-KDL]

Ok I will
I know my power steering vacuum isn't hooked up.my valve thing on it is broke and has been since I bought the car. on the way home i decided to play around and watch my gauges and i found out that it only starts to smoke at or below about 25inhg vacuum. at 22 is just barely smokes. at cruise my vacuum is 15-16, when i shift or slow down it drops to 21-22 then goes back to 15ish when i hit the gas again. if i slow down in gear from about 3k it pulls 28in vacuum and smokes bad. i know i still have to do my compression test just didnt know if this would help someone give me something else to try. thanks for all the replys and ill keep you posted

 

[Poodles]

PCV or possibly sucking in brake fluid would be my guess, unless the rings are screwed (compression test )

 

[7M-KDL]

shouldnt be pcv, all my stuff is disconnected. it is not recirculated i mean so there should be no introduction of oil to the intake charge at all. the pcv pipe is vented straight to my can and i disconnected the pipe from the throttle body and plugged both of those ports to see if it would change anything. i just didnt know if maybe i was pulling to much vacuum and there was something else i should check for. if that is normal vacuum then that is just one more thing i can rule out.

 

[Poodles]

Exactly, PCV puts vac. on the crank case to help seal the rings, without it hooked up it will suck oil past the rings...

 

[gaboonviper85]

my car at idle runs about 14 in of vac (vac is measured in inches not psi) just so you dont get confused on that. And i believe when i come off throttle on decel it is around 18-20 then drops back 14 or so.

I good strong engine should be 12 plus iirc. someone please input corrections to this post if needed

7m with factory cams should run 19-20in vac.....at 75mph in fifth I usually run 10-15in vac....idle 20in vac....decel 24in vac

 

[NashMan]

yes if your master on your brake booster goes bad it will leak into the booster filling it with brake fluid i scene this many times before

and every time you hit the brake it sucks up some brake fulid

easy way to find out is just tape the booster and should sound hallow or the same though out the tapping

as for your rings if this just happen little bit after brake in mots liky had to tight of ring gap cause excessive ware on you cyclder walls

that or your ring carbon-ed up and if carboned up you see an odd ware on the cyclered way can be scene if you have borra scope

to fix this is mopare combustion camber cleaner and let ti sit over night then drain oil cause that shit is nasty


so all in all a comp test one wiht oil and one wiht out wiht the thottle plate fully open and so you do wash the cyldersc pull your efi fuse

that or dot he simple oil cap test and slighy und it and see if the cap hovers or flies off if it flies off you gots to much persure

 

[89supra7mgte]

Are you losing brake fluid? or feel a soft pedal?

 

[Poodles]

Easiest way to know if it's the brakes is to loosen the 4 bolts on the master and pop it away from the brake booster (breaking the airtight seal). If you hear a hiss or see brake fluid come out of there, then it's screwed.

But, like I said, you have your PCV system disconnected. You didn't rule it out, you've ADDED to the issue...

 

[7M-KDL]

its like a very slow leak and i thought my pedal felt kind of soft but then i figured it was just in my head because i hadnt driven it in so long so i was used to the brakes on my other car. ill have lots of things to test when i get home. thanks for the help, ill let ya kno

 

[7M-KDL]

So gaboon, any idea what could be causing my car to pull 28 instead of 24 on decel? The only time it smokes is once it is pulling 26ish in vac

 

[89supra7mgte]

i think the vacuum is dependent on engine tolerances build specs and so on. dont think there really is a spec of what it should be, do know a good well running engine should be around 14+ at idle. would like to know more myself though. Not sure if too much vacuum on decel is a bad thing or not? Also not sure how much is too much?

 

[adampecush]

So gaboon, any idea what could be causing my car to pull 28 instead of 24 on decel? The only time it smokes is once it is pulling 26ish in vac

your gauge is poorly calibrated, that is your answer. perfect vacuum is 29.92 inhg. Your engine is not pulling near perfect vacuum on decel.

 

[7M-KDL]

so i did a compression test and all the numbers are fine. i am still getting smoke on decel under high vacuum. i really just dont understand where it is coming from. i had a ct-26 that was bad so i repaced it with a boss that was good and it didnt change anything. i guess i need to call the shop that put my valve seals in because that is the only other thing that i can think of.

also, adampecush, depending on the rpms at which the car is decelerated from will effect the amount of vacuum. the car will not pull the same vacuum when decelerating from 3k rpm as it will when deceling from 5k. at least my car wont but maybe thats the problem. if i decel from 5k it pulls ~30 on my gauge, it is an autometer cobalt so i would expect it to be calibrated properly

 

[TurboStreetCar]

also, adampecush, depending on the rpms at which the car is decelerated from will effect the amount of vacuum. the car will not pull the same vacuum when decelerating from 3k rpm as it will when deceling from 5k. at least my car wont but maybe thats the problem. if i decel from 5k it pulls ~30 on my gauge, it is an autometer cobalt so i would expect it to be calibrated properly

As he said, there is no way your pulling that kind of vacuum with an engine decelerating. When you charge an air conditioning system you pull the system under a vacuum to boil off and moisture in the system using a vacuum pump. These pumps are designed to pull vacuum and when left running on a sealed system for 30 minutes will only pull approx 28inhg. Autometer is not the most accurate of gauges. I have never seen more then 24-25inhg on my Defi mechanical gauge. This is confirmed with my internal boost/vacuum sensor inside my EMS that has never gone below ~12.5psi. 1psi roughly equals 2ingh.

You have found something in common with the smoke, High vacuum will pull it threw any seal that could be leaking. Only seals affected by vacuum are rings and valve seals.

FWIW I have smoke on start up and my new Toyota valve seals have approx 5000miles on them. I could have screwed one up or one got damaged. Either way im not looking forward to replacing them in the car.

 

[7M-KDL]

so they can be replaced in the car? i thought you had to disassemble everything. what would cause my vacuum to be that high if it isnt supposed to. my motor was just rebuilt like maybe 3000 miles ago but maybe they messed up one of the valve seals when they did it. if compression was fine(it was), then that means valve seals/guides are causing my problem right?