OK then, let me try and add some more value for the less confident (like me)…
Here’s the top of the TB before unplugging. As Tim says above, there’s 4 plugs (2 on top, shown here), the 3rd is round the back (you can just see the blue lead below the black plug at the top) pointing diagonally down, the 4th I didn’t even bother with until I’d taken the TB off, it was just too hard to get to. You also need to remove the throttle cable. Initially I pulled the throttle open which gave enough slack to unhooked the cable off the guide (as seen right at the bottom of the pic below) and remove the TB which then made it easier to get the end of the cable out of the TB, as well as remove the cable guide from (black) bracket on the TB…
You can (just about) see the 4 connectors here. Also note the ‘4 bolts’ are actually 2 bolts and 2 nuts and the potential to lose particularly those nuts down the engine bay is quite significant (wish me luck getting them back on without loss)…
Now, I whipped that little IACV blighter off the bottom of the TB; thankfully somebody had previously ‘Dremel-ed’ a straight cut across the two 5-point star screw heads (not even 6-point torx!) to make this easier…
There you go, pretty yucky in there. As you can see (thankfully!) the seal held together, which is good because the local Honda parts dept were useless and I hadn’t found the part number on the Web.
To be able to spin the shaft in the IACV take the black sensor off the end and note the little metal tab at the end of the shaft (that you see when removing the sensor) sits at the top (the open side) for when you put it back on.
Right then, time for a clean up!
I’ve read that petrol, WD40 and (from the ether) various other chemicals are suggestions so feel free to suggest the rights/wrongs and I’ll let you know how it turns out.
It wasn’t quite as smooth as I’d have liked. If you held it vertically by the shaft and spun the body it’d spin about 360o, which is probably about 3x before but still not uber loose. I decided to reinstall it anyway.
It worked.
Well, reasonably well. Sits at about 1300rpm once warm and bounces down to 900 briefly every minute or so. Are others like that?
Gasket was a good idea but I reused the one on there as it held together when coming off.
Now, my problem. I struggled to get the front bottom nut on. I ended up dropping it down the back and heard it land on the undertray. I’m not worried about it causing any issues down there and expect it to fly out in the not to distant future, however, a few queries about the missing nut (for me and the others that follow)…
Would you drive it with a nut missing?
What type/size/material is that nut?
Where to get one?
How do you fit it?!
More than happy to receive material and assistance at Anglesey if it’s safe to get that far.
No Ian, don’t run it without a nut on. There are four fixings for a reason. I know you Honda boys love chopping mounts off your gearboxes and crazy stuff like that, but these things are there for a reason.
Get yourself another nut, I would use a nyloc one. Put the nut in your socket, you can stick it there by doubling over a bit of sticky tape and putting that in the socket first. Then put a small extension bar in the socket and use it like a screwdriver to get your nut started. That’s what i do when access is tricky.
But what do you mean by “cap head” in reference to helping to reattach it in its tricky location? I was thinking of something along the lines of lining a socket with a bit of blutac to help keep it from falling out whilst I got it seated on the thread.
I shall limit my use to carefully running it 200 yards down the road to the garage where we’re going swap the exhaust on the lift in the hope that the nut is still on the undertray.
Do silenced CRPs fall apart? I believe mine is just a bulged pipe to a perforated pipe through the middle. I’d hate to swap the exhaust to find that was part/all of the issue.
A leaky exhaust can sometimes cause issues. Leaky intake tract is the more likely culprit though.
A leak on the intake side does the same job as your idle speed control valve, as it lets air into the engine that has bypassed the throttle body. Obviously the more air, the more the revs will rise. Your idle speed control valve can obviously mask it to a certain extent, but can only go to the point where it is closed completely, if the leak is still letting air in the revs will still rise.
You can also put your finger in the throttle body and cover up the intake side of the IACV hole… if that ‘cures’ your idle problem, then it’s definitely a sticking IACV valve - looking at the condition of the throttle body I’d put money on it being the IACV.
Mine did it a couple of years ago after it had been sat in the garage over winter… if they haven’t been used for a while, it’s not uncommon.
I agree with Sean, I wouldn’t run it without the nut… shouldn’t be too difficult to get an extendable magnet onto the under tray to fish the nut you dropped out.
