i was driving my 93 hatch (B16A), i have been getting a chattering noise lately.
i also noticed that when i try to hit vtec in 1st gear i doesn't switch over, but it will switch on the otyher gears.

i should mention this is not my DD, but i don't think that has anything to do with it.

 

You got 5k post and still didnt put up any info on your problem. Cells?, did it just start doing this, any other symptoms?

 

That chattering could be from your transmission. Can you notice the vtec engaging? or do you just not hear it engaging?

 

Hmm that's weird, try replacing the VTec solenoid with one from a junkyard or borrow from a friend really quick? Chatting might be from clutch or trans.

EDIT: Maybe MAP sensor?

 

sorry for repling late, i noticed a couple of hours after posting that the vtec engaged. prior to this it was not engaging.

there are no CEL's. i did noticed it started after i replace the oil pan gasket.
now, i have no leaks, but the pan i have came off of a spare block that i have and it has a nice size dent on it. not sure if that plays a part.

 

yeah, that can cause your oil pressure to drop, or rise?? and that effects your vtec. iunno why its only happening in first, but switch it out with a dent free one and it should be working normal again.