Topic: PCV valve question.

[BikerTrash]

Is the dang thing really necessary? The old trucks and cars didn't have them. They don't have emissions testing here. and by capping off my port that draws on the PCV valve, my truck has finally started running like a toyota should for the first time since I put the webber on it. I dont even have to have the mixture screws and the Idle air screw all jacked around with like I did before to get it to run.

 So does the PCV valve serve a purpose besides drawing in crank case gasses to be burnt, or is that all and I can just cap that off and run a little universal breather filter off the front of the valve cover where the hose went to the factory air box?

[79coyotefrg]

if removing it makes it run better  it was messed up,

it makes things cleaner  and  even though we dont need cats and stuff,  its the least we can do

[tech201]

The old cars didnt have pcv valves and most old cars dumped oil. The pcv helps with reducing crank case pressure wich can cause oil leaks.

[BigMike]

I have heard that the oil vapors drawn in from the crank case help lubricate the valve seats prolonging their life.

[*ROKTOY*]

Yes, it is the only means of ventilating the crankcase of any explosive vapors that may accumulate in there. The older vehicles used a road draft tube which pulled the fumes out as you drove down the road. Without it you could have a crankcase explosion.

[BikerTrash [OP]]

Well, it does not matter, the truck running correctly was a fluke, so the PCV is hooked up again. I played and tinkered all week trying to get it to idle and it was no use, only way I can get it to idle is to take the air cleaner off and choke it with my hand to make it have enough vacume to idle. Every gasket on the intake is new, the carburettor has been gone through, I even took someones advice and reset my valve clearances.

So it is getting down to the point I am going to have to bring it to someone who knows better how to fix it.

[79coyotefrg]

Well, it does not matter, the truck running correctly was a fluke, so the PCV is hooked up again. I played and tinkered all week trying to get it to idle and it was no use, only way I can get it to idle is to take the air cleaner off and choke it with my hand to make it have enough vacume to idle. Every gasket on the intake is new, the carburettor has been gone through, I even took someones advice and reset my valve clearances.

So it is getting down to the point I am going to have to bring it to someone who knows better how to fix it.

that in bold tells me your fuel pump aint pumping

[BikerTrash [OP]]

OK, But if I keep my foot on the throttle it will run, but not under about 1,500-1800 rpm. the fuel pump could possibly work at higher RPMs but not at lower? Either way I will change it out when I go home on Wednesday fuel pumps are relatively cheep. Figure I should just go to an electric fuel pump while I am at it?

Either way thanks for the help, Y'all clearly have the patience of Saints, I figure would have been run off pirate long ago

[fordh8r]

I had one do this to me a while back. Turned out something got stuck in the idle circuit of the carb (plugged it up) and it wouldn't idle for crap but ran fine otherwise. Tore down the carb cleaned it out real good and VIOLA! she ran great. Whatever was in there was real small cause I never did see it. 

If you do this, just be sure to clean every orifice you see with it apart. 

[BikerTrash [OP]]

ok well, when I get home, new fuel pump and then if still nothing take the carb down again.

[jimbo74]

if removing it makes it run better  it was messed up,

it makes things cleaner  and  even though we dont need cats and stuff,  its the least we can do

the one closer to the firewall, that is connected to my carb, if removed makesmy truck stall, is that right?

[81 Yota]

Was this issue ever resolved? I am experiancing the same problem.

[BikerTrash [OP]]

I ended up pulling the entire intake off and replacing all the gaskes from the head out all the way to the carb base gasket. Found a mistake I made when I installed the adaptor plate for the Weber, I mounted the first plate fine, then the next plate I  threaded the studs in too far and they bottomed out in their holes against the lower plate causing it to open a small gap.

Got all the vacume leakes fixed, reset the carb like the instuctions said, had to end up going up one size on the idle jets, now  it runs rough (but it runs) till it finishes warming up, then runs like a top. Sorry 81 yota on the long delay on the reply, been hanging out mostly on my clubs forums lately.