Bought an 89 Civic Hatch today knowing that it had some problems but not sure what was wrong with. I'll give u a list of the symptoms.

1. At idle rpms Jump up and down
2. Moments after car has been started white smoke comes out the exhaust not a terrible amount but more that what condensation would cause
3. Car did not overheat after a 30 minute trip home and after sitting idleing in my drive way for 10 minutes after getting home
4. After getting home there was no more smoke coming out the exhaust at all. Idle was still bouncing though

My first thought because of the smoke was a headgasket, also i heard that sensors could cause the idle problems. I'm not sure at all whats goin on with the car hopefully someone can help me. The only has 120,000 miles on it, it is the 1.5 DPFI 4spd

 

was the car idling low or was it just around the 1, if it was idleing high i would probley say the coil pack

 

theres no tach but it sounds like to me it bounces from about 5 or 600 to about 1500 r's and this just happens continuously when stopped

 

change your battery. seriously, just try it once. Do you have a battery you can get from another car? Try it once, and tell me what happens. I'm kind of curious.
White smoke is a separate problem,though.

 

Well i could swap out that battery from my 93 del Sol and try that, but prolly not till tomorrow. Could the battery cause the idle to do that. The guy today tho gave me the receipt for the battery cause he said he just put a new one it. I think the receipt said he bought that battery in August should i still try it?

 

My hatch would go from about 700-1200 rpms, then back down, then back up etc. I changed the battery and it stopped. Does that sound like what your car is doing? I swapped out the battery and for some reason it stopped. I was just curious to see if yours would do the same.

 

smell the smoke (not too much, you'll go deadbrain) coming out of your exhaust. Coolant has a distinct scent from oil, which are really the only 2 likely things to be coming out of your tailpipe.

 

the unstable rpm can be caused by a faulty O2 sensor. Also you will want to have your eacv cleaned out. Its located on the right side of the intake manifold if i am not mistaken. It has 2 hoses that run coolant towards it. It also has a green electrical connection clip that is connected to it. It is held in by 2 bolts. Try taking that out and cleaning it, sometimes that helps. Also check if your ecu is flashing any codes.

 

Well i checked my ecu (thanks jigga JJ) and i found out that it showed flashing codes for fuel injector and for Electronic air control valve. I ran a bottle of fuel injector cleaner through the tank today to try to help that out. I went to autozone and they priced an EACV at 210 bux!! Theres no way i'm gonna pay that so the guy at the desk told me to clean it with carb cleaner so i think i might try that tomorrow. Does anyone have any advice on how to clean out the EACV. If you do any idea would help thanks alot

 

Also check your PCV Valve and hose...mine had similar symptoms and when I changed that it settled down...just a thought.

Sometimes too when I disconnect my battery for an extended period the engine will seems like it is slightly "revving" between 500 and 1500 rpm...after awhile it settles down to normal though...

White smoke typically means antifreeze...(blue=oil, black=fuel)

Hope I've helped and not confused you further...

Jason