Stalling when Oil cap removed

Got a question for everybody, is this normal. I actually had my car running yesterday :banger: , and I decided to unscrew the Oil cap on the valve cover. As I did the car started to stall, I tightened it down and it idled normal. I am thinking that its posible that my pcv valve is jacked and probably stuck open (water does tend to seize things up) and that by opening up the oil cap that it caused a vaccum leak (Major). Still need to change the oil about a dozon more times to get all the crap milky flows like molasses in the middle of winter junk out of the engine, burn off and or get some fresh gas ( been sitting for a while), change the spark plugs. Going to try some of those ideas that was mentioned on another post for flushing the engine. Now if I can get the car in gear, I think that the flex plat to torque converter isn't bolted up (Have an Automatic). And right now I have now way of getting the car up high enough to get underneith it.

Will also have to finish bolting my exhaust manifold on, missing a couple nuts and one of the studs is striped going into the head. (Hmm, Jb weld, a drill and the right size tap otta fix it)

that is normal for your car to stall without the oil cap screwed on. mine did once when i forgot to put it back on.

Yep, my old '84 CA20 did the same thing also. I never thought much of it since it ran fine with it on.

man thats normal, my healthy ca20e does just that when i remove the 710 filler cap. these engines are eaps pickey when it comes to vacume and air lines and the sump and head are all interconnected and if one line or in this case, cap, is removed, then we got a leak in the system and the engine just shits its self and stalls. Dont worry bout it man, its perfectaly normal with this engine, IMO.

Are you sure it's normal? I used to take mine on and off fine, filled it up with oil with the motor running once or twice when the starter motor died and i didn't want to stop it :P

Thanks, I thought it was something like that.

i thought that was a sign of worn rings / boars

this is the answer i got from google :roll:

As the engine is exposed to air this then allows the very fine balance between
the AFM and IACV to totally stuff up and more importantly not ALL air is coming
through the AFM so the ECU no longer knows how much air is coming into the
engine. Not to mention as air is introduced into the system between the AFM and
IACV.

It's a sign of bad valve seals, or blown rings.

No air should be able to get from the valve cover into the combustion chamber.

Does the car burn oil too?

no man the pcv valve will make a loop whith the valve preather and if u disconnec that u lose that air flow

hmm weird see what i dont get is i took that pipe that goes off the valve cover to the intake tube off and replaced it with a filter...and either way all the air that gets up in your head and block area is is just blowby and its already acounted for so the car shouldnt be affected if that is is just blown to atmoshpere... theres got to be something else thats causeing this but i cant see what

well yeah u can put a filter on in but teh hole where the hose goes in to the intake has to be pluged. But see in his case he had all the stock hoses on it including the hose that went to the valve breathernow if u unscrew the oil cap u introduce a huge vacumme leak and will case the car to die

well yeah u can put a filter on in but teh hole where the hose goes in to the intake has to be pluged. But see in his case he had all the stock hoses on it including the hose that went to the valve breathernow if u unscrew the oil cap u introduce a huge vacumme leak and will case the car to die

yes yes yes you are completly right..

i think it might be a small problem, but my car runs perfect........powerfull for a CA and has uber high comp, so no worn ring there and mine stalls with the filler cap removed.

Neb, your car was a freak!

i dunno bout it man, as long as the car goes hard, who cares really... how often do you drive with the oil cap off?

thats my blabber,

catch yas

same with mine take the oil cap off and it stalls and the same gose for my
Nissan Pathfinder take it and it stalls as well .

thats my 2 cents .

Well, least I know this is pretty normal. Must aslo means that my seals and intake conections are good and tight. Now just to get under the car some how and to see if the torque converter to flex plate is bolted up. I don't think it is. Will have to find the bolts and get the car up high enough to get under it. Kinda sucks since I no longer have a jack (At least it was a cheap $20 one from Kragens that I bought a couple years ago and ended up being Frankinstained with another jack because the frame of it got tweaked). I left it under the car one day, and the next day it was gone. It would have got the car up high enough anyways. That just gives me the reason to get that larger aluminum jack I seen. Light weight and 2 1/2 ton jack that has a pretty good lift height.

..thats just weird..never heard of that... :confused:

I know that I'm a little late on the response, but I would like to give the reason for the stalling. It will only happen on CA20E's, as they are the only engine with the flap door style air intake. When you develop a vacuum leak, such as through the crankcase vent, with the oil cap off, air gets an easier path into the intake. This closes the flap door, telling the computer that the engine is sucking no air in, thus it puts no fuel in. Any hot wire system will not have the same problem. That's why Neb and Bart can don't have the problem, as they both have turbo cars.

Stalling with the oil cap off is not a sign of bad rings or seals, it is perfectly normal.

Thanks, that makes sense. Those others that are running the breather on there cars I think were all turbo cars.

Thanks, that makes sense. Those others that are running the breather on there cars I think were all turbo cars.
Must be what it is....my ca18 idles perfectly fine with a breather filter, and the oil cap off.