take oil filler cap off......STALL???

[superspit]

try this.....it could be just me.

Take your OIL FILLER CAP OFF, does your car start to stall..(revs go up and down, then dies). Take my DIPSTICK OUT, and I lose 100 rpm on idle, and slight 'hunting' occurs. What's going on here. My little brother and I did the spark plug re-gap thing tonite on my 33 (.8mm to compensate for extra boost), and beautiful...no more missing, car runs well !!(idle was now at about 600rpm from 650 rpm before re-gapping) ....BUT, just to check the oil cap, i took it off and noticed the enging was going a little silly, then died. Re-started with cap back on...no problem. Took dipstick out, car immediatly dropped a little off idle speed!!!.

Bro and I thought we'd put something back in wrong, or forgot a pipe etc..but all looked good.

PLEASE....anybody experienced this?..the motor seems fine, other than this bulltish!

Thans again.

Mark

[Cecam]

It will stall. Normal, don't worry about it. Your just creating a big airleak in your intake from the plumback from the cam cover to the intake after the afm. Something along those lines anyways.

[superspit]

It will stall.  Normal, don't worry about it.  Your just creating a big airleak in your intake from the plumback from the cam cover to the intake after the afm.  Something along those lines anyways.

So C, this only happens on r33's (turbo ones?)? My S13 Silvia, and mums Silvia don't do it. In fact, i've never seen this before, until tonite. What you're saying seems feasible though. Thankyou, I'm guessing you'll either get 'backing' on this by our fellow Skliner's.....or not.

Thanx man.

[T0nyGTSt]

Surely opening up the oil system results in a sudden loss of pressure - the ECU should see this and the results is as you see it.

T.

[knore]

mine dont stall

just plays around with revs for awhile

[vspecv]

some cars suffer from this more than others, nothing to worry about. its normal, when your crankcase pressure reaches a certain point pcv valve lets the pressure out, but only small amounts at a time , so it doesnt affect the way it runs.when u take the cap off it releives all the pressure and thats why it runs rough.

when your engine runs it builds up blowby which builds up pressure in your engine and the pcv rids the system of this blow by, when u pop the cap off, you are robbing the engine of vacuum and thats why it runs rough

[Craved]

so what does the ecu actually do when it does this? lean off? drop timing? any ideas?

[vspecv]

nothing to do with ecu, as soon as u rob the engine of vacuum , it removes the vacuum from the engine ancilleries.

[Craved]

of course, just looking for ideas to solve a different idle issue!

[Zagan]

Want to be careful about taking the oil cap off, oil can spit out the engine and it's very hot and will burn skin on contact very quick, and will be hard to rub off also burning skin where you rub it over.

Same with the dip stick.

That's why cars have a warning saying don't open the oil cap when car is running.

[vspecv]

they usually have a sticker that says dont open radiator cap, engine oil gets hot, but not that hot!

[Zagan]

Yep, and it for that very reason why they have to other wise people would be sueing the car companies.

After all there's only so many times you'll get away with your stupidty.

[superspit]

So, I guess I won't worry about it then. (ta VSPEC)

But relying on the Dipstick and oil cap seal just to get a good, constant idle really 'erks'e me.

The safety issue is valid too Zagan.

Thanx Guys,

[[ant]]

mate i had a similar thing. i had an S13 silvia SR20 and it used to hunt abit and then sort itself out and idle a bit rougher with the oil cap off.

but now i got my R30 skyline with an FJ20 u take the cap off and it hunts then conks out. i thought it was ****ed too but nah its normal hehe

[superspit]

']mate i had a similar thing. i had an S13 silvia SR20 and it used to hunt abit and then sort itself out and idle a bit rougher with the oil cap off.  

but now i got my R30 skyline with an FJ20 u take the cap off and it hunts then conks out. i thought it was ****ed too but nah its normal hehe

Thanx ant,

I feel betterer now!!

Mark