Fuel Trims are high and + with vented oil cap

**PWNED** · 05-10-2015

Recently after my phenolic IC install I have seemed to plug my pcv (the front) as my oil cap gets sucked in. After numerous removals I said screw it and stuck a hose In the side of my oil fill neck as you see so it can breath, as it is my only car right now so I need it to drive. Buying a house.....

Now at idle my ltft is around +4-10. If I plug the hose it goes complete opposite as if it was non intercooled (was usually around -4 to -7) at idle (as I drove the car for years and know what my trims are usually at)

Now in my non IC days during crusie they were basically locked at 0 for both.

Now it is very sporadic. For a few minutes they will usually be +2 to 5 then all of a sudden pegged to +16ltft. Let my foot off to try and get it to clear and nothing. Sometimes have to blip the throttle to get them back down but may or may not spike back up.

Now say they are +16ltft if I get pissed enough which I have been lately I will pull over and the car will idle down and ltft will drop down to +5to7.

What is going on here? is it my vented tube?

I have sprayed my lim/IC with brake clean and no change in idle felt.

**Scottydoggs** · 05-10-2015

dont the vent tube from the valve cover need to be routed to the throttle body?

**SgtMarshal** · 05-10-2015

I did a similar thing but for a different reason. I had to much crank case pressure so I'll was oozing out my dip stick tube. I ran a pcv line from the oil fill cap and routed it to the nipple on the throttle body. I'm not sure how is different than your current setup, but it might be with a try.

In a side note, a lean condition usually indicates a vacuum leak

**PWNED** · 05-10-2015

I cant attach that tube to the tb nipple due the to crank case is sucking. Thus if i attach it inplace of the plugged nipple after maf (purge connection) it wants to stall the motor. Or am i doing it wrong?

**Scottydoggs** · 05-10-2015

you do this to the TB. http://www.grandprixforums.net/threa...cover-breather!

**PWNED** · 05-11-2015

Wouldnt that be the same as putting the line on the port where purge would go? Im not runnin stock maf. I have an lq4.

**PWNED** · 05-11-2015

In the above link I don't think that will work as it is after the maf and I am running lq4.

As seen in the picture the top left vacuum plug wont work as that pulls a vac and so doesn't the line off the VC.

I am thinking on running the line to where my IAT sensor is to see what that does.

What do you guys think?

**BillBoost37** · 05-11-2015

You need to route the pcv tube to the correct place, like Scott suggested. If you read that thread he linked you to, it explains if it's pre TB plate and post maf.

With it vented, you are allowing unmetered air to be pulled into the crankcase and up through your current rear pcv. Hence.. more air than expected and fuel trims are + to compensate for the unmetered air.

**Scottydoggs** · 05-11-2015

drill and tap this plug under the TB.

**bandook** · 05-11-2015

Originally Posted by BillBoost37

You need to route the pcv tube to the correct place, like Scott suggested. If you read that thread he linked you to, it explains if it's pre TB plate and post maf.

With it vented, you are allowing unmetered air to be pulled into the crankcase and up through your current rear pcv. Hence.. more air than expected and fuel trims are + to compensate for the unmetered air.

Exactly. Pull your oil dipstick and your trims will go even higher. All you have done is cause a vac leak. Do as suggested.

**PWNED** · 05-11-2015

Does anyone have a link to a fitting? My local home depot does not carry angled fittings.

**BillBoost37** · 05-11-2015

Google it

**SgtMarshal** · 05-11-2015

I'll snap a couple pictures of my setup later, but there was a brass nipple on the northstar throttle body already installed when I put the throttle body on the car.

this was before I actually ran the pcv line, but this is the nipple we are talking about.

http://i1115.photobucket.com/albums/...psqvu14toj.jpg

**BillBoost37** · 05-11-2015

Pat.. if you were in my area, I have a ton of these things. West Springfield. You heading this way anytime soon?

**PWNED** · 05-11-2015

Originally Posted by BillBoost37

Pat.. if you were in my area, I have a ton of these things. West Springfield. You heading this way anytime soon?

I am willing to pay you (to ship) but I just emailed Ed (phenolic maker) if he had some.

Sorry for the confusion. I spaced out that the link clearly said PCV port is what your are drilling into.

My other question is that "stock" if you take the cap off it will blow at you. With front pcv plugged it is sucking!
With that being said does it change the characteristics on how the pcv should work now?
When I connect the line to the port I need to drill out will the car see that air is being sucked out? Or will it just tie all together to the rear and think nothing is wrong?

At idle/crusie the pcv valve should be open correct? Once it sees boost it will shut. Correct? Even with a breather on the oil fill will it still do this?

I know I am over thinking this but when I have an issue I like to know in depth details.

**BillBoost37** · 05-12-2015

PM me your addy. I'll see what I can do. No promises..lol I'm better in person than shipping these days.

**PWNED** · 05-12-2015

I see some are hooking the line form oil cap to before the throttle plate and after the maf.

Is this the same as drilling a port on the bottom on my throttle body and connecting to there instead?

Say I fix my plugged front pcv later on sometime and leave this line hooked up. Are there any ill effects?

I am lq4 maf. Stock maf is there cut in half to plug the hole (bought like that)

**PWNED** · 05-12-2015

A little update. As you see my new line from oil cap to intake (after maf/before throttle plate) My trims are now +-3ish at idle instead of a +7. Now at first I thought my "vacuum leak" was fixed. Then I see my wideband drop and see my trims are jacked at crusie..

! Don't pay close enough attention.
Drive home im at the light and trims are near perfect start driving up the hill and park and they are NOT happy as you see. So then I notice my 02 is pegged pig rich!! Blipp the throttle and no fix. I had to unplug the sensor to get the trims back in check as you see. I do get insufficient switching at times with my 02. But this is the worst the car has acted up. As you see the trims leveled right out after I unplugged it. Who thinks the 02 is jacking my trims up? As I could not find any vac leak with brake clean days ago.