drivefast

Ok I have a 87 firebird a couple of upgrades. But i believe it may be the stock 305ci carbureted block. Im having two problems. first is that after sitting a day or so theres a cloud of white smoke from the exhuast when i start the car. after about 20 secs if that its gone and no more smoke from tail pipe at all. im thinking valve seals is the issue with that. Also The cat converter has been deleted if that makes a difference. I'm not too pressed about this issue tho. My second and biggest problem is with smoke coming from breather cap on passenger side valve cover. It doesn't smoke all the time but mainly when you press the gas pedal or pull the throttle. I have a pcv valve on driver valve cover and I checked it, it sucks fine. No smoke however coming from driver side valve cover. So next I'm thinking to do a compression test, maybe my piston rings are done and it's about to be a bad day. But I could surely use any advice on what anyone else may think the problem is. Ill come back n update as I learn more.

Edwardgp

Sounds like you have it under control. The compression check and a vacuum gauge reading should tell you whats going on in the motor.

vetteoz

iTrader: (13)

Typical
Lo vac when throttle is open so no vacuum to suck the fumes through the PCV system into the engine
so they come out wherever until the vac rises to make the PCV work

drivefast

Possible ways to fix the low vac if that is the case? Thx in advance.

vetteoz

iTrader: (13)

Don't use the throttle

If it really worries you remove the open breather on the cover and run the line to the air intake/ filter
like a stock setup so the lo vac fumes go into the top of the carb

TTOP350

iTrader: (8)

1st problem is valve seals.
2nd problem is most likely just oil vapor that should be venting up to the air cleaner housing instead just lettn it blow out.

Do a comp and leak down test tho, to make sure you don't have big blowby.

drivefast

Here's a pic if that helps. There is another vac line on the front of carb that's not being used. It's where the blue cap is on the carb. So are u saying I should run a vac line from where breather was to that?

TTOP350

iTrader: (8)

I would ditch that aircleaner 1st.
1 backfire and you'll wish you had a fire bottle on board. (they are known to catch on fire)
The breather on the pass valvecover needs removed an a elbow with pipe running up to the side or bottom of a stock type aircleaner.

If you had the stock stuff on the car, look at how things were routed and the Emission decal.

drivefast

Gotcha. Ima do the compression test tommoro and see if that brings bad news . Then the vacuum test. Anyone kno what my reading should be for both of those? I'm assuming 150-180 on compression test but mainly being in the same ball park for each cylinder . But I have no clue what I should be getting back on the vacuum line test. And if all comes up good ill install that line to a different air cleaner.

vetteoz

iTrader: (13)

Your setup is all wrong anyway.
You are using the pissy little port intended for dist vac as the PCV port.

The PCV line is supposed to go to the large center port on the carb that you have your brake booster hooked up to.
Booster line normally goes direct to the intake manifold or the rear port on the carb as shown in the pic below

TTOP350

iTrader: (8)

Good work Vetteoz, I was trying to find something like that.