Russell117

I just replaced the head gasket on my 96 d16y7. And my idle is fluctuating from 1.5k to 3k rpm. I've replaced the iac valve, MAP sensor, and throttle position sensor and set to .50 . Still can't get the idle normal. Throttle cable is fine no vaccume leaks

Wankenstein

Check vacuum line from cruise control to middle of intake manifold.

Russell117

Car doesn't have cruise control. Should there be a bypass for the vacuum?

Wankenstein

Not sure. I'm used to EX (D16Y8) models. There may or may not be a port on the intake (firewall side) for DX, LX models? You didn't state the model. If it's an EX it should have cruise control and if it doesn't someone removed it.

The port I'm referring to is labeled in this diagram as: To Cruise Control Diaphram

Wankenstein

Have you tried bleeding air from the coolant system?
Did you smoke test for vacuum leaks? Smoke testing is the safest method.
Make sure PCV valve is fully inserted to crankcase grommet.
Did you clean the throttle body?
Idle air screw adjusted correctly?

Try spraying TB cleaner spray on TB gasket and intake gasket area while idling. A leaking TB or intake gasket can cause idle fluctuation. If there is a leak idle should raise when sprayed with TB cleaner. Do this while engine is cold and have a fire extinguisher nearby.

Russell117

It's an ej6 sedan I don't think it came with p/s cruise control or anything. Just the base model.

Russell117

Did all of that. New throttlebody/intake manifold gasket, idle screw set no vacuum leaks. Pcv valve is correct. No air pockets in coolant lines. Gone over it all seems like 100 times no fix

Wankenstein

New IACV oem or aftermarket?
When you unplug IACV from harness does it hold steady idle?
Did you do an ECU reset/idle relearn?

When the head was off did you use a razorblade and brake cleaner to get the cylinder head and intake mating surfaces as clean as possible? Those old, dried paper gaskets can be hard to get completely removed. A lot of threads with similar idle issue as your's end up being resolved with a new intake gasket after everything else tried didn't solve the issue.