Ok, I had the valve covers off fixing a couple minor drips and the guy at the local bug shop said "you might consider putting a "crankcase breather" kit on those valve covers. It is suppose to help on older motors relieve pressure becuause of blow-by and thus help with oil leaks." The kit came with two fittings that attach to the valve covers and some 1/2 inch tubing which runs to a box that you mount above the enging somewhere. Any oil that collects in the box is suppose to run back to the motor when it is turned off. Cool--I'll try it.

Well, I start the engine, I'm mean I try to keep it started but the engine acts like it has a huge vaccum leak. So I check on my hoses on my L-Jet, all is OK. So I plug the two taps on the valve covers and what do you know--runs perfect!

"Houston, we have a problem..."

So what's the deal...???

Just a heads up.

If you are ever going to run on the track, you'll need to get a much bigger breather box.

The first time I ran with the "Bug Performance" breather box at Thunder Hill, I finished the run and smelled oil. When I opened the engine hood there was oil everywhere (overflowing from the breather box).

After I replaced the box, with a much bigger one, the problem went away.

I think Summit has some reasonable ones.

Sorry, I can't help on the vacuum issue.

I don't think L-Jet needs valve cover venltilation. It gets crank case ventillation through the oil cap. My 75 L-Jet does not have any breather tubes or nothing from the valve covers or heads. I believe that what you got was designed for a D-Jet or carbed engine.

I may be wrong...

I _think_ LJet requires that the crankcase hold at least some pressure. DJet and Carbs don't care.

your "bug shop" guy is an idiot. those are for carbed engines that don't have the stock setup (routed into the airfilter) anymore ...

ask him what, if anything, he knows about L-Jet injection. i'd be surprised if he can speeel it ...
Andy

If you un-screw your oil cap it will run the same way. On that engine you need crank case preasure.

that "can" be used on an L-let, I've done it a few times with a different catch tank (homemade)...of course to do so, you need to remove the breather line from the oil-filler to the rubber elbow that attaches to the throttle body....

you do not need crankcase pressue for the motor to run...you just cannot have too much unmetered air on the backside of the air flow meter...remove the lines going into the rubber boot, fill in with plugs...no worries besides polluting the atmosphere with blow-by

Well, I start the engine, I'm mean I try to keep it started but the engine acts like it has a huge vaccum leak. So I check on my hoses on my L-Jet, all is OK. So I plug the two taps on the valve covers and what do you know--runs perfect!

"Houston, we have a problem..."

So what's the deal...???
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The problem is that you still have a direct connection between the crankcase vent (at the oil filler) and the air intake (just after the air meter). If you remove the link (pipe) and thus break the connection between crankcase and the fuel injection system your problem will disappear. Plug the hole in the S-tube where the pipe was located and connect the oil filler vent to your new box. By the way, your car will run just fine with the EGR disabled as well.

I have never heard of an engine that wants a positive crankcase pressure, unless of course you want all your seals to leak.

The guy who recommended the kit (and sold it to you?) is a moron. Stay away from people like that. L-jet is a closed system, and must be free of ANY vacuum leaks. You certainly don't need any kind of crankcase pressure relief in a 1.8 or 2L T4 with stock injection. The Cap'n

On a stock L-Jet system, you cannot vent the crankcase.

The fuel injection system requires the crankcase to be well sealed up (it runs a vacuum). Even leaky o-rings on the oil filler cap can let unmetered air enter the intake and cause running problems.

Plug the vent hoses you installed and remove the catch tank.

On the other hand, if one were to modify the L-Jet and plug the vacuum lines from the intake to the crankcase, the engine would run fine with a "vented" crankcase.

plug up these (red arrows) and it'll work fine...no vac. leaks or issues with the crankcase....


Click to view attachment

i'm not saying to do it...I'm just pointing out it can be done....

The same is true for the L jet on the bugs, oh Krusty one. Try pulling one vacuum hose and see how crappy it runs.

In my experience, the people working the counter at any "Bug Shop" are complete morons, and my limited knowledge far surpasses that of anyone there. Every single time I get anything from Bugformance, I pretty much have to walk them through finding what I want, and often think it would save time if they sewed their mouths shut so they don't spew out any more disinformation.