so my car wants to idle sometimes at 1750 after startup. she warms up and get down to about 1200, but wont go below that even after 10 minutes of driving.

recentley like 5 days ago, I bypassed the air outlet hose from the top of the manifold, and T'd it into the PCV line.

possibley this could be screwing up the PCV. or Idle control valve.


any suggestions on what to look at?

 

I'm guessing what you did is related, but I'm not quite understanding what you did. Can you take a picture or draw a diagram?

 

Did you replace the PCV with a straight through fitting?

 

um, no. left the PCV in place, then cut the hose about 3 inches down the line, put a T in, and from the other air vent hose, the one that goes to the intake elbow, I unplugged that from the elbow, and plugged it into the bottom of the T.

but these symptoms didnt happen the day i did this mod.

started happening about 3 days later, or about 100 miles later.

oh, also, put a cap on the inlet to the elbow.

 

Why did you do all that? Were you having a problem before?

I'm still not quite understanding what you did. If by some chance you have opened a passage for manifold vacuum to be exposed to atmospheric pressure, then you'll have a high idle like you are.

Remember: Anything behind the throttle is manifold vacuum. Right at the throttle plate, there may be some ported vacuum, but in the intake pipe, there is very little, to no vacuum at all.

 

Exact same problem I was having my man.

Go look at that catch can thread, I posted what I did to fix it.

Go to Autozone or Checker auto, one of those stores, and get a brass fitting that matches the threading and hose size of your PCV. Remove your PCV and replace it with the fitting.

No more idle problems.

That's exactly the same way I've got mine hooked up. Both valve cover hoses go to a T, then in one line to my catch can.

 

^^ ah yes, ya see thats what im gonna have to do too ! thanks mang


Redz, why didnt you get another PCV ??

did you ? and it didnt work ?

so the fitting you are talking about is like an air hose fitting for an air gun from a compressor



tiburons dont have a ported butterfly,

in my manifold there is 20 pounds of vaccum at idle, accoding to my boost gauge.

maybe you dont understand tiburon intake systems too well, you should do some researching.


redz ... thanks mang

edit 5:14

thinking about it a little, and Im not sure a brass fitting in place of a PCV would be bad in a boosted motor.

with a N/A motor, during idle, im getting 20 psi of vaccuum, and during WOT, i get zero psi. according to the cobalt boost guage, map connected to the manifold.

if the motor was boosted I would be putting the boost pressure into the top of the motor, through the brass fitting and hence create pressure in the top of the head, pshing the oil back down into the pan, away from the cams.

Im just gonna buy a new PCV, thats probably sticking closed so no suction is being created, thats why all my oil is coming out the vent, into the elbow, and Im getting a ton of oil in the throttle body.

the PCV is for oil, the vent is for air.

 

Please don't tell me to do more research. How many automotive certifications do you have?

You pretty much repeated what I said. Yes, there will be ~20 inches of vacuum in the manifold. That is correct. However, none exists in the intake pipe, and yes, there is ported vacuum at the throttle plat, it's just not used. Now, depending on where you routed your pipe, which it sounds like you placed it right at the manifold, it could be causing an unmetered flow of air into the engine. The crankcase vapors are pressure from the cylinders that blow by the piston rings. This needs to be vented out of the engine, but not directly to the manifold. If I were you, I'd replace the pcv valve and put the system back to stock. It's not like there are any horespower to be gained there anyways.

And you're pretty close about the boosted engine idea. If you were to go into boost, it wouldn't really push the oil down away from the cams, but you'd definitely blow some seals.

 

Because another PCV would have done the same thing. Trust me, 2uniq and Gary explained the whole thing here some time ago, so I went and tried it, and it works absolutely fine now. No idling problems.



It's not that, not at all, a new PCV would still have the same problem. I replace my perfectly fine PCV with a brass fitting, like I said, and the problem completely went away. Again, as I said, there are several threads about catch cans on here, and I've posted what I did, with the part number, in several of them. Probably the same ones that the other guys posted in.

No, I won't go find the thread, you are perfectly capable of that.

LOL

 

wow, green, dont get your panties in a bunch bro ! haha

I dont need certs, I have god given talent.



yea, I like Redz idea, using a brass fitting while not boosted.

but today, I ran the car, and no idle problems.

im sure its a STUCK PCV.

Redz, i couldnt find your posts on the oil catch thread,

but i did find DTN's thread on cleaning the internal stock "catch can" which is exactley what im gonna do.

thanks