I had some time this morning to mess with the car. So, I tested the FITV per the manual and it's acting as it should. Lots of suction when cold and none when hot. The car will now idle when cold but kinda low but it needs some throttle to start. When hot it will not idle at all. I pulled a couple vacuum hoses off the intake to allow more air in and with the 2 on the far end of the plenum off it idles perfectly and drives well. Turn the A/C on and the idle picks up a bit as does putting it in drive (auto), makes me think the IAC is working. So here's what I'm thinking as I cannot see anything else that allows air flow.
1) IAC is not opening enough but it seems to move properly and I don't want to pay $250 on a possibility and according to the manual you set idle with it unplugged.
2) Some sensor that controls the idle isn't working properly, I plan on testing the coolant sensors next.
3) The idle is not set properly but why would it have idled properly before replacing the head? Did it have a vacuum leak before the swap? I do see that the butterfly is shut tightly when idling, maybe it should be open a crack?

So I'm going to try to compare the Accord to my son's Civic which appears to have similar idle electronics.

 

Throttle plate should close completely. Not open a crack. The little mechanical stop=screw is used ONLY to prevent it from wedging stuck closed.

Find the little idle-air needle valve in a hole above the throttle bore (#1 in the picture).


Set the BASE idle like this...
Get the engine all warmed up.
Turn off ALL loads (electrical & AC).
Unplug the IACV (it'll want to stall so nurse it with the throttle).
Adjust the idle-air needle valve for 550 rpm.
Turn it off, plug the IACV back in, let it cool down.

Then force it to re-learn the idle behavoir...
Reset ECU (pull battery cable).
Start it cold without touching the gas pedal.
Let it warm up completely without touching the gas pedal.

It might have had a vacuum leak before & several things were mis-adjusted to compensate?
Maybe the new head breathes different than the old one?
Different headgasket thickness - slightly different compression ratio?
The idle system is probably sensitive to small changes like that.

 

Thanks for the info. I tried adjusting the idle, all the way out doesn't allow it to idle without the IAC. My son's Civic seems to pull lots more air through the IAC/idle screw hole. The Civic will idle without the IAC (low though) and if you pull the map it drops then picks up again using a predeterminded setting. Obviously it sets a code. Pull the map or IAC on the Accord and it dies but also sets a code. So, I think I'm going to try driving it to work for a week and see what happens. I may spray carb cleaner through the idle screw hole to see if that helps. I'm wondering if the IAC should allow some air through when it's closed.

 

Not sure, but when the IACV is unplugged it probably closes.

 

Hey folks, I'm still messing with this car. I've been driving it to work but it's still hard to start when cold. It starts easier if you hold the gas down a bit but you can hear it stumble before it catches. Kinda sounds like a cylinder isn't firing until the others fire enough to get the rpm's up. After that it runs decent although the idle is still a bit low when warmed up but not stalling. Something in the ignition week maybe? I've read about one of the temp sensors possibly doing this, would unplugging it make it show itself? Once it's warmed up it starts easily until it cools back down.

One other thing I've noticed although it may not be related and could be normal seeing it's not my car, when driving along at a bit over 40 and the engine around 1500, the car seems like it lurches a bit. You can feel it load the trans then unload enough to feel the mechanical looseness of the drive train.

Things I've done since my last post:
-replaced cap, rotor, a 2nd set of new plugs
-cleaned the egr and passages
-verified the timing is correct since head was replaced

I'm thinking about getting a used distributor & coil on Ebay....thoughts?

thanks!

 

I'm still messing with this car. It seems like it floods itself when sitting. If you wait over night it starts right up. If you try to start it 15 mins after it has already run then it is hard to start. Hold the pedal halfway and it starts easier but stumbles at first. I thought maybe a fuel injector leaking so I pulled the rail and laid it on a bucket then turned the key to see if one leaked under pressure. No leak, I pulled the injectors and cleaned then anyway using FI cleaning spray and a battery to open the injector. No difference though, ugh. Any thoughts? I think I'm going to have to put a gauge on the rail and see how much pressure there is and if it drops of quickly.

 

Well, I've been chasing my tale on this one but I think I finally have a handle on the issue which isn't ignition or FI related. As I've stated, after the car is up to temperature and it sits for 15 mins it is hard to start like it is flooded. I spent a couple hours chasing this part down this weekend. Steps I took:
- warmed up, then shut off for 15 mins. Turned it over for a few seconds then pulled the plugs. Found 2 of them wet but not with fuel. Also see steam coming from 2 of the plug holes..ugh.
- dried the plugs, warmed it back up again, shut off and pulled the plugs. I taped some q-tips to skewers, put them in the plug holes and checked them every few mins. The cylinder on the distributor end had a wet q-tip after 10 mins. One other also got a bit wet but not as much.
- lastly, cleaned the plugs again and released all the pressure from the radiator. started and warmed up with the cap loose enough to let the pressure out. Started fine the 2 times I let it sit with the cap loose.

To conclude...it looks like I didn't get a good seal on the head gasket so I need to dig back in. I'm assuming the non Honda gasket (yeah, I know ) is crappy or probably more the case is that I scratched it putting the head on which is allowing coolant into the cylinder when hot/under pressure. I actually had a tough time lining up the cylinder so took it off a couple times and may have put a crease in it.

So, any advice on making sure I get a good seal aside from putting it on straight and even? The head was ground straight and wasn't replaced because of a coolant issue but because of a broken cam. I also don't lose much coolant but the overflow bottle did empty.

 

Update, someone got me curious about the head bolt tightness and I've never liked my click style torque wrench so bought a new pointer style one. So here's what I found. When I put my new torque wrench on the first bolt it showed under the 1st of the 3 tightness steps. All of them ended up being under the beginning ft/lb so I stepped through per the manual until I was up to the torque they are supposed to be at. Looks like my click style wrench is off by about 40 foot pounds. I can't believe the car ran as well as it did, the problem now seems to be gone but I will monitor it and the coolant level for a bit.

 

Click-style wrenches have to be dialed down to zero for storage. The spring relaxes it's stress over time, reducing the torque. But I'm surprised it was SO FAR OFF...

 

Also, using long extensions will lower the torque you actually get on the bolt.