I have a 2000 Honda Civic SI with 37,000 miles (just off warranty). I have intake, header, exhaust, FR, FPR, FF, FI, Crane Ignition, VAFC - that's about my performance mods.
I live in Wisconsin. Ever since the temperature has been getting cold out (like below 40 degrees), I have had problems starting my car when it is cold. If I leave the car off for a few hours to overnight, it has problems idling. The symptoms are that the car idles at under 500 rpms and it is running very rich. One indication is that smoke will come off the cat (burning gas). While it is idling like this, I cannot drive the car, I basically have to leave it until it warms up. It sounds like it is going to die. If I step on the gas pedal, rpms go down and car gets close to dying but doesn't. Once warm, the car will just turn over and idle perfectly normal. It will also drive normal. If I turn off the car and start it up without it getting too cold, it will startup and run fine. When the temperature is fairly warm out (like 50's, 60's 70's, etc....), it starts and idles fine. So it is a problem with it only in cold weather.
So far these are the things I have tried. I put my stock ignition on. I put my fuel system back to stock (FR, FPR, FF, FI). I replaced the coolant temperature sensor with a new one. I replaced the thermostat with a new one and flushed the cooling system. I took off my VAFC and running stock computer. I replaced the main fuel relay (I had a new one laying around). Checked all the fuses to see if anything blew. Checked and replaced all hoses. Checked for vacuum in all the lines. Cleaned the Idle Air Control Valve and replaced gasket. Cleaned the TB as well. Checked all sensors for proper voltage and ohm readings. Checked all gaskets for leaks. Replaced the valve cover gasket. Replaced the plugs and wires. Did a compression test on cylinders and compression is good. Valves were adjusted in range. Replaced the PCV Valve. Checked EGR Valve. Now the car has been like this for a month now. I would like to avoid the Honda Dealer if possible. Also, yesterday I threw the main O2 sensor (Code popped up). Not really sure if that is the problem since I have been running the car for a month now with no thrown code. Don't want to jump to conclusions that the O2 sensor is the problem because I don't want to replace it and have it blow out again. I am thinking it may have went out since the car was running rich and maybe burned it out (I know those things are touchy). Can the O2 sensor just go out and not throw a code right away or be sending the wrong signal? Any help would be useful. I looked around the boards at similar problems but so far nothing has helped. Thanks.

 

If you ask me.. I'll tell you it's your battery..

Because you see.. A battery has a CCA rating on it. CCA stands for Cold Cranking Amps. That's the amount of Amperage (Current) that the Battery can allow to be drawn out at 0 degrees.. At 80 degrees, the Starter will draw 100% of the Starter Draw. At 30 degrees, the Starter will draw about 150%. And at 0 degrees, the Starter will draw 200%..

So that means, if you've got a weak Battery, you're screwed for the Winter..

If you want to test your Battery but don't know how, just take it to a shop like Napa or AutoZone and have them do a load test on it.

Bettery yet, when you've got your car running, bring the whole car there. Have them do a Starter Draw test and a Load Test on the Battery. The Battery should be able to handle at least double the Starter Draw Amperage. If not, then that would explain why your car doesn't start in cold weather.

What could've caused your Battery to go bad?..

Short driving doesn't allow the Alternator enough time to charge the Battery. Parasitic Drains will drain the Battery and leave it discharged. Which will result in a Sulfating Battery. Thus reduces the CCA of the Battery..

But that's just me.. Good luck..

---Oh.. And here's a word of advice.. I never replace anything in a car unless I have tested it and made sure that it doesn't work properly..


[Modified by PnX-R, 7:46 PM 11/7/2002]

 

Well I took the battery to NAPA and had them do a load test on it I would say 2 weeks ago. It tested out fine. I could see where you are saying the battery could be the cause. If the battery is low on amps, it will not send the right amount of power to the components that need it.
I think I only went out and bought like 2 or 3 new parts to replace. The rest I did tests on following what was specified in the Helms manual. I had to put most of the car back to stock so I could see if that would rule out performance parts and also so the Honda dealer would actually look at my car.
But thanks for your advice. What I may do is get another check on the battery. They may have done a load test on it but maybe the tests were inaccurate or not done right.

 

[QUOTE]If you ask me.. I'll tell you it's your battery..
QUOTE]

 

I just installed a new battery in my sister's 98 Civic EX a little more than a month ago (should have thought of that before doing a battery check a few weeks back). I am sure that it will be sufficient. Tomorrow I will try swapping out my battery with her's and see what happens at startup.
Another suggestion from someone else is that I could have a tank of bad gas in my car. Maybe some water got into it. He said that when the car is cold, it would have a tough time idling, but when warm, the car would burn off the water. Any thoughts on this theory.
I will let you guys know if the battery fixed the problem. Thanks for your help.

 

I got up very early this morning and first tried out my sister's battery in her EX. I turned off all unnessary accessories before running the car. Still had a problem with the idle. I took the car to Sears Auto after that since it is a block from my house (after letting the car warm up for 10 minutes). The battery and alternator checked out fine normally and under load. Any other suggestions as to what I may try would be helpful. Thanks.

 

Do you have a heated O2 sensor(4 wire),if so I would test it to see if it is getting voltage. Kind of sounds like O2 sensor isn't warming up quite right or something. EGR possibly?

 

So when Napa performed a Load Test.. What amperage did they test it at..?.. Because if the performed it at twice the STarter Draw.. I would have to say that you've got high resistance in your first Starting Circuit..

I would do this.. When it's cold outside and the car isn't warm, test the Starting Voltage at the Battery and the B Terminal and the S Terminal of the STarter Solenoid.. If I could get those readings, I can further help you..

 

Well this morning the temperature was about 40 degrees. The voltage of the battery was around 12.5 volts. Since it is still pretty cold in my garage and the car has been sitting for 3 hours, I checked the voltage of the starter. The voltage was about 8 - 8.5 volts (don't have a digital reader to get very accurate). I tried it with 2 different volt meters just incase one is off or not working. My friend helped me do a crank test. We cranked the engine to see if the starters voltage went up. it went up to around 12 volts as well. Since I am now at work, I don't recall the highest amperage rating of the battery. I think under load the battery's amperage was around 200 amps. I will double check this when I get home.
And then to SP (didn't see your post right away), I checked the O2 sensor a while back. I checked it from a cold start all the way to warm. It seemed to be working properly. I have thrown 2 O2 sensor CELs in the past month. I think my car throws them when the car is running very rich. If I reset the computer and start up the car when it is warm outside or when the car is warm, the CEL will not come back. The Honda dealer said it is probably throwing this because the car is runing so rich that the O2 sensor is throwing a code. Also, they said this is probably not the problem because when you first start your car, you are in open-loop mode until the o2 sensor is warming up. Thanks for the help.


[Modified by undertaker, 12:53 PM 11/8/2002]

 

The voltage at the Starter was 8 to 8.5V?.. That's while cranking?.. Which terminal did you check the voltage on?.. If it is the terminal with a cable coming from the Battery, then that means your Battery isn't strong enough supply the Starter with the Amperage it needs to turn..

You said that you cranked the engine to see if the Starter's voltage went up?.. And you said that it was sitting at 12V also?.. Which Terminal were you on?.. If you were on the B Terminal, that would mean that there's an Open in your first Starting Circuit.. I bet it probably didn't click either huh?..

Because if it didn't Click and you're getting 12V at the B Terminal of the Starter Solenoid, it would mean that the Pull In Coil isn't getting either Power or Ground. Because you can't have 12V at the Starter or its Solenoid..

My guess would be, if you didn't hear a Click, is that the Pull In Coil isn't finding a Ground in the Starter because there's an Open in the Starter..

But I could be wrong..

Oh, and the part where the Battery's Amperage was 200 under load.. How much load was it??..

 

I am not absolutely sure if it was that exact voltage on the starter. I was in the car turning the key while my friend was reading off the numbers. My voltmeter may be bad as well. The 2 we have are like 20 years old and are needle driven, not digital. I highly doubt it has anything to do with the starter, alternator, or battery. The lights don't go dim, CD Player and everything else electrical works fine, with the car running or without. Car will start and turn over perfectly normal. There is no hesitation with the starter turning over, turn the key and the car is running, warm or cold. I replaced the battery with a known good one (out of a '98 EX, no change). My problem I believe really doesn't have to do with starting the car at all. I have no issues with the car to lead me to believe that it is something electrical. It has to do with a problem with the car not idling properly when it is cold, after the car has been started. It's either the idle control valve, a sensor on the car not getting the correct info, or maybe my ECU is just all messed up because when the car is cold (under 45 degrees), way too much fuel is being sent to the car. So it is some sensor that is telling the car to send more fuel than it should. Once warm, it seems like the car starts to lean out on fuel consumption and the car runs normal. Maybe it is just as simple as a new O2 sensor like the other guy said. I have all the numbers sitting at home on the battery load test. The battery tested out good because Sears said I didn't need a new one, so did NAPA. I will pick up a digital voltmeter and recheck all the voltage readings so I get true accurate readings. I am not trying to get upset with you about your conclusions, but this is getting frustrating because I work on my car everyday trying new things to see what the problems are for at least a month. I do appreciate your help because it does give me other ideas of what could be wrong with my car and it doesn't hurt to check.


[Modified by Undertake4, 9:12 PM 11/8/2002]

 

I had kind of a similar problem with my civic. When I would let it sit for about 4-7 days it would act like it didn't want to start. I check the battery with a voltmeter and it read 2.5 volts, so I know my battery was shot so I replaced with a new one. The only problem is the battery that came out of my hatch was only 2 months old! And I didn't leave anything on so I don't no where my battery was getting sucked power from. My car runs like **** whens it cold also I let it warm up for 10 minutes, this damn IAC value on b16a.

 

I drive my car mostly everyday. The only time I let it sit was for about 4 days this past week waiting for a few parts to come in. The last few weeks before that I drove the car with this wierd idle problem because I was working on my winter car, so I didn't have much of a choice. I would probably think it would be the battery if I let the car sit for a few days and then try to start it and have this problem. Yesterday it was 40 degrees outside, I had problems. Today it's in the mid 50's and the problems are gone. That is why I am thinking, it's an IAC Valve problem. But the IAC pulls air into the engine great at startup, even when the car runs bad at idle. That would be the only reason why I would rule out the IAC. Maybe it's time just to buy a new car.