Another Idle Problem

[Amanda]

I have a 2000 Civic Cxi. Motor is stock except for a cold air intake.

Car starts and idles fine untill it starts to get a bit warmer, thats when it jumps up and down continuously. Dont have a tach so cant see what revs are.

Note: Car has been in a frontal impact but it was repaired, and it seemed the engine was OK, apart from a few little things that were fixed.

I have read a few things about fixing this problem such as:

Checking Vacuum lines for leaks
Bleading Coolant System
Cleaning IACV

I NEED to get this sorted out before the car gos over for a pitt inspection to get rego'd. I am looking for a few Step by Step tutorials, that myself and my Dad can follow to diagnose and fix this anoying problem.

Cheers
Amanda

[rayb3na_]

thermostat is busted lol

[Limbo]

Idle is funny? try searching the DIY there are a few thread on how to clean the ICV & throttle body. They should be your first options.

Then, service the car, oil, oil filter, air filter, spark plugs.

Hopefully that should fix most of your little problems

Don't even both with the Thermostat as it only affects your car temp not your idling.

[dc2dc2dc2]

why not bother?
Thats why happend to my car
i cleaned the IAC & TB
didn't do shit
then i bled my coolant properly
didn't do shit
then i finally changed my thermastat
and booyah
it went away :)
so don't say don't bother :)

[Limbo]

never seen that before even when i had a busted thermostat.
I've even run a car without one before.

It did idle abit higher when the temp dropped to less than 1/4, but it didn't idle funny

[Amanda]

I cleaned out the IACV on the weekend, bled coolant and checked vacuum lines and none of that worked. Bugger. Another thing i noticed with the idle is that once it starts fluctuating, I can put my foot on the brake, and it will stableize itself until i take my foot of, then it will go back to its evil antics again. I think I will just take it to a shop, cause i want it on the road. I hope they dont charge too much.

[CRXer]

The ECU does read the brake pedal switch to adjust idle,but i cant see it causing fluctuations in the idle as u describe.

When it happens again,try switching on other high electrical loads such as your headlights or rear demister to see if that has the same effect as the brake pedal in smoothing out the idle.

If it does smooth it out then u most likely have a problem with the signal from the alternator to the ecu.Check the wire between the ECU & the alternator for shorts to ground or open circuit & if it checks out ok,then u need to get the alternator reco'ed.

Another possibility is the ECU has a problem,is there any chance u know someone with a car like yours to do a quick ECU swap to see if that cures the problem? Maybe even visit your local Honda workshop & see if they have a spare ECU to throw in quickly to see if it fixes it.

[Amanda]

Thanks buddy ill check tonight if that has the same effect as the brake pedal.

[Limbo]

check if there is a leak in the hose to the master brake cylinder (the big black thing that is stuck to the firewall) That sometimes cause fluctions.

[SuiJin]

hope you've serviced your car, cause mines doing the same thing, but i've guessed its the coolant. mines black as lol.