today we got a few elbows from local parts place and fabricated an intake! the only problem we have was there was no place for the pcv hose to go so we left it hang! it just puts oil vapors in the intake right! AND I HAVE a check engine light now! is this the cause of the light and i need to find a way it it back in intake? help me! and is driving wit it this was bad for a few hours?
pcv hose
- Thread starter bmman93
- Start date
fourthmeal
Banned
DUDE!
You are seriously banned from touching a car until you learn how things work!
The PCV stands for Positive Crankcase Ventilation, and that air is metered air. It needs to be plumbed back into the intake, or else the system is constantly losing the air it already measured to go inside the engine.
100 Bucks says the code is a rich-run condition, and you haven't hurt the car from it...but you've got to be careful!
Edit: Also a "custom" intake isn't properly designed and calibrated to measure air properly, so you may be dealing with mis-calculated MAF outputs too.
You are seriously banned from touching a car until you learn how things work!
The PCV stands for Positive Crankcase Ventilation, and that air is metered air. It needs to be plumbed back into the intake, or else the system is constantly losing the air it already measured to go inside the engine.
100 Bucks says the code is a rich-run condition, and you haven't hurt the car from it...but you've got to be careful!
Edit: Also a "custom" intake isn't properly designed and calibrated to measure air properly, so you may be dealing with mis-calculated MAF outputs too.
People put on breather filters all the time on their PCV valves and let them vent to atomosphere. And its not even metered air, its blowby gases thats seep past the piston rings which is mainly combustion products and unburnt fuel. And its a VERY small amount of air. It only HAS to be rerouted into the intake for emissions purposes as it is illegal for it to vent to atmosphere. Not having it route back in the intake won't hurt his car.
But your probably right about his MAF readings. I'm sure thats the cause of the CEL.
fourthmeal
Banned
Ooooh...Correct. Damn I was off base there..sorry, I thought I had it. I'd be 100 bucks poorer too!
Must not be thinking clearly today...sorry about that.
Must not be thinking clearly today...sorry about that.
yes and no..... during BOOST conditions it will vent out of this tube, because the PCV side is seal closed. under engine vac. the PCV valve is open and will draw fresh air through the crankcase through this breather tube and into the intake manifold. if this air is not metered it will throw MAF reading out of whack. there is a good thread about this on "the other forum" one fellow member went out of his way to educate us on this. there are dataloggs and tons of great info showing how using an open breather will screw up your fuel trims. that and the fact that your MAF housing is more than likely improperly sized....... you wasted some $$$ dude, sorry.... put it back the right way !!
it was getting a lean condition so i stopped driving. see i thought it wasnt a big deal! but i talked to a audi/vw tech and he said its b/c its just a vacuum leack b/c its not hooked up! so im just gona get a stem fitting and drill a hole and hook it up! and another 5 bucks! and he should it should be straight
and i was under the impression that just like on a v8 u could just put a breather on it and been fine! but no our cars are so temper mental it spazed out ill let u no how it gos
and i was under the impression that just like on a v8 u could just put a breather on it and been fine! but no our cars are so temper mental it spazed out ill let u no how it gos
i hooked the pcv hose up ! had to add a nipple for it to hook onto and reset the computer and bam all fixed! drove it for 2 hours and no problems! thanks for the help! and the inside diameter of the tubing is the same as the mazdaspeed one's! i checked it b4 i started! thanks tho
How do you know it's the wrong size?
No offense, but some people think too much. I have a custom cai for about 4 months with NO cel's or other problems whatsoever. Half of the fun in modifying your car is to do it yourself. Some things you can cheap out, like an intake or exhaust, others you can't, like clutches and turbo upgrades. (bicker)
improper ID of the tubing size can seriously f*** up your MAF readings. i hope you didnt just slap on a 3" tube and say "bigger is better" cuz that is dead wrong. it's not that some think too much. it's that others dont think enough.... or at all ! the MAF is the primary sensor for your engines performance. just cuz you dont have a CEL or have a noticeable drivabilty issue does not mean all is well. i suggest you have your fuel trims looked at. i bet they are WAY off.
Welp, if you vent the pvc to atmosphere, you best be tuning for it because IT WILL suck in unmetered air. Its not so bad to cause you to blow up but enough to screw up the tune of a car. Guys were doing it with modular fords and having tons of problems. A simple check valve will work a hell of a lot better without the tuning issues.
Mine is about the same length and circumference of the ms and injen cai, So I'll say I'm good to go. It's on the "how to section" if you wana see it.
True, but not under boost which is where most people are concerned with their tuning. Under boost the pcv valve is closed in order to keep the crankcase from being pressurized. But since most pcv valve are not air tight, we get some leakage and some oil blown into our intakes.
In anycase, ideally you want it routed to the intake with a catch-can in between.
