Hey y'all, it's been a while since I've been on here. Just got finished replacing the head gasket and now it idles high on startup and when I blip the gas it surges/hunts. I plugged the port inside the throttle bore just before the plate (about 10-11 o'clock) and the idle dropped and smoothed out. Could that be a bad/dirty IAC? '98 2.3L VTEC, 4AT.

 

Yes, IACV could be stuck open due to carbon buildup. Remove and clean.


good luck

 

Along with cleaning, it might be the base idle adjustment.

https://www.hondaaccordforum.com/for...e-speed-38734/

 

Thanks guys, I'll check it out and let you know what happens. I also forgot to mention that when I unplugged the IAC, the idle dropped but it still fluctuated, though not as dramatically. Also, there are no vacuum leaks that I can find anywhere, and the cooling system appears to be full, as I opened the bleeder valve and nothing but coolant came out.

 

With the car running and the air intake hose off, manually rev the engine and start spraying throtle body cleaner through the IACV. If the engine runs smoother but maybe not exactly smooth then you are on the right track. Unless the throtle cable or the linkages have ever been messed with then it less likely to be the idle is out of adjustment, but rule nothing out until the problem is resolved.

 

It was the IAC! I removed it, cleaned it up really good with brake cleaner, and unstuck the valve itself. Popped it back in, fired her up, and she runs great! Thanks again for the help, guys!

 

They will stick open. thanks for posting your fix.

good luck

 

Okay, so real quick, when I put the trans. in neutral to coast, the idle jumps up to around 1500rpm and then slowly falls to about 950 as the vehicle slows. Before, it would fall straight to the normal 700-750 and stay there. Also, it seems to kick down a lot easier than it should when I give it gas going uphill, compared to before. Is this base idle related? Any help is appreciated!

 

Head gasket replacement generally requires removal of throttle body and throttle cables. Depending on how it was done it may be necessary to adjust throttle cable slack.

On a cold engine idle remains elevated until engine warms.

good luck

 

Right, and I did indeed remove those items. I also cleaned the intake and throttle body while I had them out. I just went through the procedures for adjusting the idle and throttle cable, per the manufacturer's instructions in the manual. The idle screw was already all the way in and the idle won't come down lower than 950-1000. Also, how do you measure the deflection of the throttle cable when you've moved the throttle plate to the stop? Is it total up and down deflection, or just deflection from moving the plate?