Car With Vortech Won't Run If Plugging Valve Cover To Throttle Body

[89gtsleeper]

just like the title says. Had this car running generally pretty well for the last few months. Drive it every day. Has a stock pullied vortech on it right now. When I bought the car, I noticed that the previous owner left the line connected from the valve cover breather to the throttle body. They also had a breather on the valve cover.

I have suspected for some time that I need to reconfigure this, since the general consensus is that that line should be pulled and plugged or pulled from the throttle body side and re-routed between the blower and mass air.

I've had tons of oil spraying from the breather over the past few months, so I put a stock style cap on instead. Car ran a bit better in low Rpm's, likely due to the fact this got rid of a vacuum leak.

So today, I finally experimented with a few things and they all resulted in the car starting and running for about 5-10 seconds trying to find its idle, running rich at around 11:1, then bogging and dying. Why would this not work as everyone suggests? Here is what I tried.

1) pull line from throttle body side and route to vortech intake tubing between mass air and blower. Used a supra turbo pcv valve inline here so that air can only go away from the valve a cover. Capped throttle body.

2) same as above but without the inline pcv, so just a straight line from valve cover to the intake tubing as described above.

3) leave tube from valve cover to throttle body, but put the supra pcv inline to only push air from the valve cover toward the throttle body.

 

[Gearbanger 101]

Have you done the obvious and checked the car for codes and taken vacuum readings at idle?

 

[89gtsleeper]

Car is stock cam. Prior to this attempted mod, my vacuum reading is around 18 at idle in park or neutral. 14-16 at idle when in gear at stop lights. Can't keep the car running long enough with the new mod to get a reading. It just bounces around trying to find an idle then dies.

 

[89gtsleeper]

Haven't pulled codes in a few months, but the car runs well as long as I just put that hose back to how it was.

 

[FoxMustangLvr]

You are EFI right? Is your PCV in the back of your intake manifold present and functioning? I believe most boosted applications people are plugging off the PCV in the back of the intake, capping off oil fill barb and leaving oil fill cap on the neck, then installing bungs into each valve cover and running lines to a vented bottle/catch can. A lot of people have success with this method. Some still see some oil in the catch if they are in boost a lot.

@TOOLOW91 @MikeH686

 

[MikeH686]

Yes with my car i had the pcv plugged and two -10 bungs welded to a set of aluminum valve covers and they run over to my catch can in the fender well.

 

[MikeH686]

Here's what my plug looks like in the back of the intake

 

[89gtsleeper]

Mike, thanks for the detailed pics. I've considered a setup like this, just trying to keep the car as close to how ford built it as possible while still getting to play a bit. I may end up going that route though. Been pulling the motor's top end apart and so far found:

- a load of oil in upper and lower intake
- a throttle body gasket that is 6 mm smaller than the otherwise matched cobra intake and throttle body openings
- stock pcv valve that I can blow a little air through without much effort
- the baffle on the passenger side valve cover was removed (which I assume is part of the reason there was so much oil blowing through the breather that was there)
- rockers that are too loose for my comfort

 

[FoxMustangLvr]

Mike, thanks for the detailed pics. I've considered a setup like this, just trying to keep the car as close to how ford built it as possible while still getting to play a bit. I may end up going that route though. Been pulling the motor's top end apart and so far found:

- a **** load of oil in upper and lower intake
- a throttle body gasket that is 6 mm smaller than the otherwise matched cobra intake and throttle body openings
- stock pcv valve that I can blow a little air through without much effort
- the baffle on the passenger side valve cover was removed (which I assume is part of the reason there was so much oil blowing through the breather that was there)
- rockers that are too loose for my comfort

Firstly you should have a baffle but sometimes having after market roller rockers makes that difficult.

Next the factory PCV is a one way valve so you should be able to blow through it one way but not the other. The valve lets pressure escape the crank case but doesn't let unmetered air back in.

Lastly. What kind of rockers do you have? Heads?

 

[Gearbanger 101]

Im running a T-Bird Turbo Coupe PCV in mine. It's what a lot of the forced induction guys recommended to replace the stocker with.

 

[TOOLOW91]

Did all this - Tried to keep the stock PCV with a turbo coupe substitute and it didnt work out. Plugged pcv and ran an open breather on the valve cover oil fill cap with the stock motor with the A trim making 7.5 psi -This was fine. Once my 363 went in and i started making some real pressure i began to sling oil out. Tried open breathers and had the same thing. END game was the same setup mike has. You could weld fittings in the back of your valve covers and use black woven hose to hide it as much as possible. My catch can is behind my pass head light in my bumper you cant see it.

 

[89gtsleeper]

When I said I could blow through the PCV, I was referring blowing intake to crankcase direction, which should restrict flow. It still let air move that direction.

Running edelbrock performer heads with edelbrock guide plates, arp hardened pushrods, and 1.6 rockers (I think they are either comp cams or crane), not sure about the springs, rubber/metal valve cover gaskets, and stock valve covers with baffle removed.

I think I'm going to try the turbo coupe PCV first, but run it through an oil separator. Get my valve lash readjusted, and see how she does.

When that goes together, I'm going to measure crankcase vacuum from the oil dipstick and from valve cover nipple and see what it reads. Question, what is an ideal crankcase vacuum at idle? This is a stock cam car.

 

[89gtsleeper]

Toolow what happened when you tried the turbo coupe PCV route?

 

[TOOLOW91]

Toolow what happened when you tried the turbo coupe PCV route?

I still was pushing oil everywhere I didn't want it to be . And I had the throttle body capped off and the oil fill port capped off to make sure I wasn't pressuring the crank case .


Sent from my iPhone using my fingers while my auto correct makes me seem illiterate

 

[89gtsleeper]

Got the turbo coupe pcv installed and got my valve lash fixed up. While I was under there I realized that the pcv hose routing was going to the middle intake tree under the intake rather than the tube on the far driver side of the intake. Swapped that out, got it back together. Seems like it lost about an inch or two of vacuum, but generally running well. Could that be due to a change in valve lash? Or is that from the vacuum line position change? Can't find any vacuum leaks between upper and lower and triple checked all of the other hoses. Now going to try re routing the line from tb to valve cover and see what happens.

 

[89gtsleeper]

Update... After doing the above, I measured my crankcase vacuum at idle from the oil fill tube. Measured about 4 inches vac. Not sure if this is good or bad, but that's what it was. I went ahead and installed an oil separator for the pcv. Then I ran the tube back from the valve cover breather to the inlet tube for the blower. Now car runs like a champ. Didn't have any issues.

 

[Gearbanger 101]

You want crankcase vacuum. It helps with ring seal.