xlee08

I have a 1998 civic dx.

I have googled and learned i needed to clean my iacv unit. So i did with no success. It was stuck when i took it out. I spray carb cleaner on it and got it pretty nice and clean. Got everything back together and it still idle's up and down. When the car is idling like this the lights pulse and so does all my interior lights. I verified there was no air in the cooling system, filters are clean too.

What else am I missing?

thx guys!

hOnda_hiEn

I'm pretty sure it's your fuse under the dash.
check you're alternator fuse. let me know.

xlee08

Someone helped me adjusted the distributor and now the lights don't pulse anymore. Engine is still going up and down. We turned the idle screw by the throttle body and was not able to find a place where it would idle correctly. I'll check all my fuses in the morning. It's too dark and cold to do anything now.

thx!

hOnda_hiEn

okay. cause last time I wrecked my car and fixed it. after everything was fixed I fired it up and idle was up and down. lights flickering. rpm needle bouncing. and it was the alternator fuse. weird how the distributor was the culprit of the lights. but as long as its okay now.

xlee08

Here's what i've done so far... i think i found the issue... but just for those out there that are having the same issue.

1. cleaned out IACV (found out 1998 dx does not have fast idle control valve)
2. cleaned out throttle body and intake manifold + adjusted idle control screw back and forth to find sweet spot
3. checked all fuses - OK
4. changed out for a working Distributor and plugs + wires
5. No air in coolant system

Still the same bouncing idle. When you hit the gas into higher RPMs.. its ok and runs fine. When you just lightly touch the idle and hold it, it starts to bounce. It runs good with a cold start for about a minute. The pulsing lights somehow went away when i moved the distributor around. Bro-in law pulled out his Timing light and Wala!!! Timing was way off the blocks timing indicators. The Timing belt is either way over due or someone totally messed this one up.

I'll report back when timing is done.

thx guys!

xlee08

Alright, its been a while.

I finally got the timing done. Timing is now correct and engine runs smooth. in this whole process, i also got the chance to adjust my valves. Purrs like a kitten.

No more bouncing idle's. Idle is still very high from cold. I did find a vacuum leak coming from the brake booster. Got that fixed, however the high idle is still there on a cold start. 1500-1800RPMS. It slowly goes down to about 1200rpms.

Weird thing is: after driving around like this at 1200 rpm and the car is warmed up, if i turn off the engine and turn it back on right away the high idle seems to be gone. (when i restart like this, i'm not cranking the starter.)

Another funny thing is before the quick restart, the car's idle stays up until i come to a complete stop. This does not fix the issue when i'm changing gears though. Between gears when press the clutch in, the idle doesn't drop. Even in neutral, the idle stays up when the car is moving.Nothing has happened to the throttle body or cable. The cable has some free slack, its not stuck or anything. The throttle body is still clean. Is there something telling the computer to keep the idle up when in motion?

All fuses are still ok, alternator and battery voltages are within range of car's spec.
tried a different identical ECU. same issue.

Anything else? thx,

slo_hatch

Idle should be around 750rpms at idle. If it is idling at 1200 rpm, you may need to adjust that screw some more or possibly adjust the throttle cable. When the car reaches normal operating temp and you turn it off, it will not idle high. It only idles high to help the engine reach operating temp quicker. If you disconnected the battery during any of this, you should need to do an idle learn procedure. Start the car and let it idle with no loads (HVAC, radio, lights, etc) for roughly 15 min. Normally from cold start (or lower temperatures) to when the fans kick on. It is normal for the rpms to stay a couple hundred rpms higher when moving than when sitting still, but not 500 higher.

xlee08

I'll try that and report back. I did this before the timing belt and the brake booster replacement, I didn't think about doing this again.

thank you

JoeSatov

When you cleaned the iacv, did you lube it? I find that a shot of silicone makes the difference

xlee08

Alrighty, I finally found time to get back under the hood.

I took the iacv off and lubed it as you mentioned. It works much better now.
I also found a link to calibrate my TPS, which I was not able to find before.
http://www.pakwheels.com/forums/perf...honda-lovers-4

Everything seems to be working well now. My check engine light went away right after the TPS adjustment.

The sluggish MPG went away when I replaced the brake booster. My MPG's got even better when I got the TPS voltage in the right spot. I'm sitting at 40MPG's combined street and highway. I think that's normal for a 98 DX.

Thanks guys!

grumblemarc

iTrader: (4)

Good job! And it only took you 14 months!