rough idle 4k topend oil on plenum
 

OK so I am diving in head first bought a 96 lx accord automatic 4cyl vtech single caM. The car idles fine then starts to fluxuate up and down normally doesn't stall but gets really close then upon excelleration the car bogs at 4k will not go past 4k (did go past 4k on first start up but only once) also noticed today that There wwas what seems like oil on top of the Plenum I cleaned it and wwill inspect again tomorrow after driving. ABS light is oon no check engine light car runs smooth under normal load. All I know is the head was rebuild and timing belt replaced all this looks true due to fresh gaskets and machined head.
Here are two YouTube links one at idle and acceleration the other tthe engine bay rough idle and oil on Plenum. Also in the engine bay video there is a weird hum or squelch sound it comes and goes anythoughs on all this thanks!

Engine bay idle
https://www.youtube.com/watch?v=zdDz...e_gdata_player

Inside idle and acceleration
https://www.youtube.com/watch?v=H1YS...e_gdata_player

For the oil on the plenum, you might want to check for a clogged PCV valve and possibly replace the attached hose.

Some guy at the parts store said my Plenum gasket is leaking causing a vacume leak and the oil on the Plenum is that possible. Is the pcv located on the valve cover?

Clean up whatever is on top of the intake manifold. Let us know if you think it is oil, coolant, or fuel (you should be able to smell gas).

There is no oil going to the intake manifold, so the intake manifold gasket is not the source an oil leak. The oil leak has to be coming from above the intake manifold, so that doesn't leave many options. Try to find the source of the leak. The valve cover would be my first spot to look at.

One thing that I noticed is that you do not have an upper timing belt cover installed. Check that the lower cover is installed. You don't want anything falling in there, or you will be installing a new engine.

Since the upper cover is off, see if the timing marks line up. If you rotate the crankshaft using a 19mm socket on the crank pulley to where the mark on the crankshaft pulley lines up with the pointer on the lower timing belt cover (if present).

Do you have a compression tester?

I would worry about timing and compression before I start to look into why the idle is fluctuating.

Also, get a 94 shop manual from the online shop manuals link in the common diy threads on top of this forum. That will show you where the timing marks are located.

Edit: After watching your video I don't think this is the problem. IAC idle oscillations are about +/-200 RPMS.

Also, remove your Idle Air Control (IAC) and clean it out as best as you can.

1.) Remove Idle Air Control Valve
2.) Remove rubber seal, set it down somewhere clean
3.) spray intake manifold cleaner in both the inlet and outlet.
4.) drain and repeat as necessary.

My IAC clogged and the exact same thing happened, minus the oil. Oil leaks can occur as a result of pressure problems caused by operating under bad pressure conditions. If your car has idled with a bad IAC for a long time, it can kill the MAP sensor and maybe cause minor oil leaks, but I doubt it.

It is definitely oil, however I see no leaks anywhere and also don't Snell burning oil and my oil level has not changed if it does not come back maybe it was from the head install. We will hope it does not return. Will check the pvc clean the iac. There is no lower cover either i ddid see ththe uupper in the trunk will check again for the lower. Plan on going to the junk yard tomorrow so if I do not have one I will pick one up and check it out. I no longer have a compression tester will see if the parts store loans them out what readings would I be looking for? Thanks

I had a significant leak from the VTEC switching solenoid on the pax end of the cylinder head. It might be possible for oil from there to reach the intake manifold area shown. An oring gasket was the cause in my case. This might have something to do w/ rpm limits. If vtec is disabled, the ECU may limit rpms.

good luck

Yeah vtec only works for the first 4 min or so of any drive u have a location of this part or picture?
Did find a vac leak looks like its coming from a box front driverside would assume abs box (abs light is on) any one know where it is supposed to connect there is no hose connected there are two right next to each other in the middle of the upper fire wall close to the throttle body

Attachment 19032

Have a new vid will post when I get home now the idle goes between 1k and 1500 back and forth does this help solve my issue lol

That looks like #24 vac line....since you have a hot air intake I bet that was removed when it was installed.

Didn't read everything...are you sure there are no codes? You say no engine light, but they could be stored.....does this only happen when the engine is warm?