Ds1

So I did an oil change, put 9 quarts in and then drove the car around to warm up so I could check the oil level and add the last quart. But, when I removed my oil cap, the car stuttered and died.

Obviously, this seems to be some sort of weird vacuum thingy going on with the oil tank. I thought I had heard someone have this problem before - any suggestions of where to start? I can't see any cracked hoses so far.

Peter Zimmermann

Common problem. A lot of mechanics out there will replace the crank breather hose, and not realize that it has a tapered plug-like device shoved into its oil tank end. That plug must be installed in the breather hose to prevent your problem. It effectively reduces the ID of the hose down to about 4 or 5mm. Do a search for the part number, or call the oldest guy in your local dealer's parts department, or when I have time later today I'll try to find the number for you.

ron mcatee

Ds1, the item Pete is referring to is a Restrictor, P/N 930-107-289-00-M260 on Pelican. Cost is $15.25. Good Luck.

Peter Zimmermann

Ron - THANK YOU!!!

Ed Hughes

Or, Peter correct me if I'm wrong, an improperly set idle and a "big" vacuum leak could do the same? The hoses are easy to check, for the most part, but I'd get some ether and spray around your intake connections, particularly where the 6 manifold connections meet the heads, and see if you get an RPM increase. That will be a leak. Include the boot, the ISVS connections, everything. On older cars, all of these can be suspect. My elbow hose on the ISV wouldn't clamp tight enough, unless I clamped on the raised rib, as a for instance.

Ds1

Thanks guys! I'll check it out tomorrow. The car runs wonderfully besides this problem, so I don't know how suspect those "other" vacuum leaks could be (I would think I would have noticed them already).

theiceman

As ed points out if your idle isnt high enough it will die when you take the cap off.

Hydrocrust

Hi, Folks, I've got the same issue, 82 SC, am looking at Pelican, Bentley, and The Katalog right now.

I can see the two breather hoses coming off the tank filling neck, but I'm not sure which of these is the "crank breather hose" that Peter refers to. Is this the upper or lower one shown on the photo in Bentley? Looks like the upper one is rubber, attached to piece with woven cover, whereas the lower hose has a woven cover/material.

I would like to look to see if the restrictor is in place as intended - do you know how far down I would have to look, or if it should be right where the hose is disconnected?

Thanks for your guidance. Andy

Peter Zimmermann

The restrictor fits inside the breather hose that connects to the filler neck just below the oil cap. The part should be visible in the first couple inches of the hose.

Hydrocrust

Super, thanks, I'll take a look. Andy

1986 Targa

Hope this helps:

Ed Hughes

^^Mine was nothing like that-it was inside the breather hose.

Peter Zimmermann

Actually...

Ed Hughes

That is what I had

Peter Zimmermann

Sorry, Ed, I didn't mean to ignore your earlier post. You are right, an incorrect idle/mixture can mess with the FI enough to cause problems, but that didn't seem to be the case with this issue.

And I know that when you saw your restrictor that you took appropriate measures to be sure it was installed properly on your machine, new breather hose or not!

Anyway, hope you're well and enjoying the 993!