Duralast vs Hitachi (OEM) IAC (finally solved high startup flare) + comparison pics

[Fix4Dirt]

Good luck, I have a feeling it will work out with the new part.

One of the nice things is that I no longer grab the attention of everyone in the viciinity when starting my car in the supermarket parking lot...

I do wonder if my engine, or at least the timing components, would be in better shape if I had installed the OEM IAC 2 years ago, and started using the poor-man's preoil back then as well. Must have done thousands of high revving cold starts with those 2 seconds or so of dry rattling at startup...

luckily its only been a few months but this ones got 329k on it so its not exactly new either... and yep it definitely catches people attention when you start it

 

[usapadyra]

So something annoying has started happening with the new Hitachi IAC.

The valve has been getting stuck in a slightly-too-open position, giving me a high idle around 2k / car pulls itself if in gear.

Three times I have stopped, taken the valve out and used my pinky to nudge the cap back. This sorts the issue straight away.

When I nudge it back, it has a slight resistance and makes a tiny creaking sound. It's not smooth.

I sprayed a tiny bit of penetrating fluid in there, let it sit for a while then blasted the inside clean with carb cleaner.

After that, on a 3 hour drive today it only happened once. But that's still one time too many for me.

Is there a reliable way to stop this sticking? Or do I have to return the part and find an alternative?

 

[J_C]

When I clean mine out, I shake out the excess solvent, then stand it on end with the solenoid facing down and put a drop of light oil on the shaft at the bushing/bearing and let it seep in for a few hours. YMMV whether that helps enough.

 

[Fix4Dirt]

this one does that too where if i let go of the brake it hits 15 or so and just idles at 1.3k in drive and 3k in park i dont know why it comes and goes in this one what helped was certainly changing the pigtail. but yours doesnt seem that

 

[usapadyra]

When I clean mine out, I shake out the excess solvent, then stand it on end with the solenoid facing down and put a drop of light oil on the shaft at the bushing/bearing and let it seep in for a few hours. YMMV whether that helps enough.

Thanks, I'll try that. So the electrical connector down and the valve holes up?

As for oil, could I use a drop of 5W-30? I have a quart sitting open already...

 

[J_C]

Yes valve up. 5W-30 is worth a try and I have been using 5W-20 but this is with mine having wear, ideally on a new bushing you'd use something less viscous. You might move the valve up and down a few times once the oil has ran down to the bushing to work it in better.

 

[donalds]

When I installed my oil catch can on the PCV system I noticed my idol air control valve will stick once a year
Now there's no oil vapors from the PCV system to lubricate the IAC lol

You may want to check your PCV valve

 

[usapadyra]

When I installed my oil catch can on the PCV system I noticed my idol air control valve will stick once a year
Now there's no oil vapors from the PCV system to lubricate the IAC lol

You may want to check your PCV valve

Hmmm on my engine the IAC gets it's air supply from a hose that connects to the main intake tube just after the MAF sensor. I'm not sure that any air from PCV venting can get into the IAC? Or can oil vapour rise up and get inside the IAC via the 'output' hole (the hole that air flows out of into the manifold during regular operation)? I could see this happening when a warm engine that's been running for some time is shut down.

So last night I took out the valve and placed a couple of drops of 5W-30 on the shaft of the solonoid piston while setting it solonoid down. It flowed down and slowly dissapeared so figure it must of made it's way between the piston shaft and the bushing. There was still a slight sheen of oil on the piston shaft this morning when I checked it before re-installing it.

Drove a couple of hours today. Mixture of steady driving, stop start and idling. No issues. Throttle feels really responsive.

Another thing I noticed - normally on the first start of the day when I touch the throttle for the first time, the engine bogs down a bit. Doesn't matter if in gear or park / neutral. This morning it didn't do that. Maybe the lubrication is helping the valve close quickly as soon as the pedal is depressed. Who knows. But I feel like oiling it slightly helped a lot.