EG Idle problems

[daver00]

Hi everyone, I have an EG Civic, 92 model, dual carbs, just got it some new registration after it has been sitting around in the yard for a few years. Everything goes fine for a car of this age and condition, except the thing refuses to idle at any sensible sort of idle speed. It will run at below 1500 rpm but at 1000 rpm it basically had it and will just give up. This is especially noticeable when you put it in gear (auto) it will just stall and die. I've got it idling up at 2000(!) rpm and when you put it into drive or reverse it will just stall out.

I've checked over all the vacuum lines, found one was split and replaced it but nothing changed, everything else seems fine. I replaced the spark plugs but again nothing changed.

It is really especially noticable when you put it into gear, the revs just drop too much, I mean 2000 rpm down to below 1000 rpm and then stall? Thats just silly.

Any help would be much appreciated as I'm just stumped right now and I'm not really very clued up on the honda stuff.

[Sir_vtec]

Sounds like the only other problems are; fuel pump, dizzy, or the fuel itself if its been in the car too long i'd probably drain it and fill up again.

[daver00]

Fuel was bad, but I've put new stuff through it, it runs fine under load, when its going it is great, very smooth not a missfire at all. Under load on the highway at 100 there is no breaking down, no loss of power and no missfire, so I've ruled out fuel pump and filter, I've replaced the filter but if the pump was bad, I'd get breakdown under high loads.

I just took the distributor cap off, and boy was that guy filthy! Not only was it corroded up really bad, but there is oil in it! I think the dizzy is leaking oil from inside the engine! I cleaned the cap out with WD40 and scraped as much of the white oxide off the posts as possible, it has improved things slightly but it still stalls unless I have the idle speed up around 1500. But with the stop screw set this high it runs on after turning it off...

Off to the wrecker for another distributor?

[Sir_vtec]

I was right! :)

If the fuel was foul, i d suggest you change the fuel filter as well

[daver00]

I've already changed the fuel filter, consequence of sitting in a yard for so many years, the fuel lines and filter were shot and leaking.

Still have not yet change the dizzy so I'm not sure just yet, although its looking likely. I'm thinking perhaps the idle circuit in the carbies is blocked but the dizzy is easier to deal with so I'll start there.

Cheers mate!

[daver00]

Ok, I've found exactly what the problem was... big suprises here it was the:

Idle Air Control Valve!

Like every other damn honda idle problem I've found on the internet. I basically, almost by fluke, pinched off its vacuum hose and suddenly all problems disappeared, so I've unplugged the little bugger and its all working correctly again.

So heres a question: What will it do to my little honda if I just leave this thing unplugged? Or should I really go and source another one from a wrecker?

[MikeyG]

clean it... theres a diy here.. it will go away

[daver00]

Not on this model, seems that the IACV on the carb models is not the same, can't be disassembled like the efi models. I'll see how much one is from the wrecker, but I want to know what the consequences for my car if I leave it off for a bit?

It seems like it is sticking, either 100% on of 100% off, rather than having a continuously smooth transition.

[ozR18]

might have the same problem..keep us posted.

[daver00]

ozR18; You can find out easily, (I'm assuming you have a dual carb model here) theres a vacuum line coming out of the top, middle of the air filter box, it goes into a little solenoid on the intake, then a line out of the solenoid into the intake manifold. You can just pinch one of these lines off to get a quick idea, or simply unplug the solenoid. Thats how I worked it out.

Other models have the same device in different places, but the idea is the same: it is just a solenoid which allows fresh air to bypass the fuel system. Find some fat vacuum lines which fit this description and you've got it.

[daver00]

Ok. Looks like its not a good idea to run around with the IACV unplugged... little honda was down on power and then overheated very quickly on a short run down the highway. Good idle, bad everything else. I've plugged it back in now and I'll look at cleaning it or replacing it,

But now the honda keeps overheating even after I've put the thing back on! Argh!

[daver00]

Bump.

Ok, I have got myself a workshop manual and performed some checks. My IACV checks out ok, my O2 sensor checks out ok. Now heres the thing, if I pull the backup fuse on the computer so that it resets, the car runs perfectly for about 15-20 minutes afterwards, no stalling, nothing wrong. However after that time it just starts to stall out again. Any ideas?

[hayashi_1986]

Are you getting any check lights on the dash?

[daver00]

Nope, no dash lights, no codes from the computer, nothing. I'm stuffed if I know what is going on. I guess I should just replace every single vacuum line and see if that helps?