Hey guys,

I've just recently acquired a '93 Accord LX that's been a southern car all it's life and shows the battle scars of it's 230K miles that it's covered this earth...Mostly just the dead clearcoat! Anyway, I bought the car which had only had minimal maintenance performed outside of normal oil changes/etc....So, the preventative maintenance game began.

Here's a list of items I've changed since owning the car...

-Timing Belts/Tensioners (ContiTech/OE Quality)
-Waterpump (Genuine)
-Valve Cover gasket (Genuine)
-Cam seal (Genuine)
-Powersteering fluid (Genuine)
-Coolant flush
-Front brake rotors/pads (Brembo/Brembo)
-New battery, and positive terminal
-Front motor mount
-Fuel filter (Genuine)
-Idle control valve (Genuine)
-Ignition plugs
...etc, etc.

Anyway! So, the car had idled fine when we purchased it, only when I had the battery and the positive terminal replaced have I had some issues with the car's idle. Basically, it'd idling too low, but whenever revs start falling, when you're coming to a halt, the engine sometimes dies/stalls. This is even more evident when the powersteering pump is in use, obviously.


So, here's how the stories gone thus far...

*Replaced the battery/terminal and was unplugged long enough for ECU to lose it's memory, simply has to re-learn...No big deal! I'm more than used to this w/ Motronic in BMWs! Well, after some time, it doesn't seem that it wants to re-learn.

We try a few different things to try to help this process, we went ahead and grounded the car out, twice actually...Never provided any results.

Following this, we removed the idle control valve to see if maybe (for some reason) it was just really stopped up, which it was! So, we're thinking...Maybe the ECU had simply started to adapt to having very little air flow? We clean and replace, nothing! Didn't even make a difference.

So, at this point we're wondering if for some reason there's a vacuum leak that wasn't showing up pre-battery replacement...We soak hoses/etc. in carb cleaner, and no stumbling or anything.

We're getting frusterated at this point...So, we're seeking instant gratification, so we start fooling with the idle screw and pulling the idle up to see if we can just manually do this. Well, we eventually get the idle pretty high, too high in fact...It starts the surging up and down, as the ECU is trying to pull the idle down. No problem! We'll just bring'er down a smidge and see if we can come to some middle ground. Well, this never helps anything, not surprisingly. So, we do something even goofier, and stretch the throttle cable to where it's not even hitting the idle screw, to eliminate any possibility of it dying! Well, this provides several issues, everything from it idling far too high, to the familiar surging we were experiencing earlier.


I'm wondering at this point, if simply cleaning the ICV wasn't enough, so I decide to replace...So, I spent the few hundred dollars on a brand spankin' new, OEM ICV. I'm thinking at this point, surely this'll take care of this issue! Well, long story short...It doesn't. Went ahead and cleaned the high-speed idle control valve out, with no results either.


....


Sooo, fellows I'm wondering what you guys might recommend I try next?


There's obviously something to the post-battery replacement that's provided some of these issues, just wondering what I might try next? ECU?

Any help is greatly appreciated!

 

Check that the pcv system isn't clogged.
If the IACV was indeed clogged, you may have to clean the throttle body as well. Sometimes residue from the PCV system can build up around the throttle plate to the point that the IACV can't compensate.

Was this car garaged or was it stored outside?

P