Ok so I just did the head gasket in my turbo d16z6
The head was resurfaced so I had to remove the IM I installed a new IM gasket aswell

So when my IACV is UNPLUGGED the car idles fine.
However there is a a fluctuation ONLY at 1500 Rpms...
When I plug the IACV back in it does the same fluctuation at idle..

Originally I accidently forgot to plug it in.. And got code 14
Then I noticed it was unplugged.
When I went to plug it in. I noticed one of the wires were broke.. So I used a butt connector to fix the broken wire.. Thinking this would solve my problem I plugged it back in.
After resetting the code..
I'm still getting the same code and a fluctuating idle now.. If I unplug it the idle is fine.. But I get the hesitation/fluctuating idle at exactly 1500 Rpms..
I seen other people have had similar problems..
But my car never did this before the head gasket install..
So I'm curious if it could be the wiring to the plug?
Maybe I didn't get enough of the wire in the connector.

I can also tell the plug has been cut and fixed before with heat shrink

I'm running s200 if that matters

I'll try and upload a video if it will help

 

Oh and I also had to change the rocker assembly..
So I adjusted all the valves.. But I feel this isn't related.

 

Make sure your cooling system is bled thoroughly. If you are getting air bubbles in your iacv it will cause idle fluctuation. When you engine is completely cooled removed radiator cap and make sure the radiator is completely full with coolant. Next start engine with rad. cap still removed. Allow car to get up to operating temp until thermostat opens up when the thermostat opens up and coolant is in full circulation the coolant lvl should lower to were you can add a little more showing that there was air in the system. hope this is the problem. Easy fix if it is.

 

Hey thanks for the input.. That is basically what I did..
First startup after the head gasket I filled radiator.. Had the cap on though.. Turned car over a few times to get coolant in the motor.. Started the car...
Opened the cap.. And added more coolant.. And let it idle..
If I let it idle with the sensor plugged in it immediately fluctuates..
I'll try again tomorrow.
I will start it with the cap open this time..

Does it make a difference if I have my temp switch bypassed with my fan on constantly?

 

i wouldnt think so but then again it might. The only thing having the fan running constantly should do is keep more of a load on the engine which should make it idle just a hair higher to keep up with it. But I wouldnt think it would be anything significant.

 

Check that you haven't mixed up the IACV and evap purge plugs (evap purge wont throw a code)

IACV wire colors: yellow/black and blue IIRC (the main colors are defintely yellow and blue, I'm a little hazy on what color the stripes are)

Evap purge: yellow/black and red.

 

Try a different ecu

 

******* A batman
If you are correct then that is the problem,.
I'm running a d16A vtec.. So I don't have an evap
The wire plugged into my IACV right now is yellow/black and red..
So that just might be it unless you got them backwards in your head.
However I can't find another plug for the life of me!!

 

Trying to get your posts up?

This is NOT ecu related.. My ecu was fine 2 months ago.. And everything is running as it should..

 

94eg8 you were absolutely correct found the other plug!! And bingo!!!
Thanks for remembering the wire colors off the top of your head!!

And thanks everyone else for your responses it is all greatly appreciated!!!

 

Glad you got it sorted out

 

Me to! So no wonder the other plug wire was broken. Because I didn't need it!! Haha
Been awhile since I pulled **** apart..forgot all about evap since I don't have one.
When you mentioned it I was determined to find a plug not plugged in!
It was folded over and fell behind the charcoal canister.

 

Any thoughts on a code 22?? Vtec pressure switch..
I took off the vtec solenoid when I had the head re surfaced. I did NOT replace the gasket..
There is plenty of oil.
What else could it be if it isn't the gasket?..
I'll pull it off tomorrow. And see if it needs to be cleaned..

 

Usually if you take them apart the plunger is stuck (you need to take the two halves of the solenoid apart to get at it, spray with brake clean or carb cleaner and get the spool valve to move) or the screen is plugged. I'd recommend you replace both gaskets as they tend to get old and hard and leak pretty bad.

Check the wiring as well.

 

Thanks man I'll check it out tomorrow.
I doubt it's the wiring unless maybe one of the plugs isn't snapped in all the way..

The light doesn't come in right away or every time
I mean I'm not driving the car at the moment but I have been changing small things and starting it everyday testing my battery

 

So this is the reason the I got a cel 22.. This wiring is old and falling apart on me!!!

 

Anyone have a thread on how to re pin this thing? I can't for the life of me find it

 

Stick a pick or jeweler's screwdriver in that black center piece in the back and carefully pry it out. Remove the white insert in the front the same way. Then you should be able to see the tabs you need to depress to unlock the two pins.

 

I destroyed the black rubber plug...
Oh well, I'll heat shrink really well..