Rep Power: 0

Hey guys just have a quick question. My car hasnt been the greatest on gas recently and think something is up. (only 450km on my last tank usually get 600 or more during summer) When I start my motor when it is cold it will start to bog down and almost gets to the point where it stalls. It usually will only happen once and then once I start driving and doesnt happen again till its cold again. There is no check engine light on so nothing for me to scan. Im guessing its an air intake sensor or fuel sensor but not sure... Just changed the 02 sensors last winter so dont think its them. Anyways let me know.

Thanks

 
Rep Power: 0

Trust me im having the same issues also but as u can see this site blows cause no one can answer it. unless you found the answer if u did let me know i would loooooove to find out

 
Rep Power: 0

figured it out on my own ..thanks....website..not! if you have the same issue as i do replace your ect sensor (engine coolant temperature sensor) thankshttps://www.civicforums.com/forums/images/smilies/rockwoot.gif

 
Rep Power: 0

Thanks man, hey how much was the sensor and how did you find out that was the probelm? Easy to replace the sensor?

 
Rep Power: 0

Hey guys, I need some help to located this sensor and know which part exactly I am replacing. I called the auto parts guys and they told me I could be talking about 3 different things when I told them Coolant temperature sensor. I think I know where it is but would like to know for sure that I am looking at the right part and know how to change it.

Thanks

 
Rep Power: 227

You don't want to replace parts at random. It gets expensive and frustrating. Any CEL codes?

If there are no codes, try this:

 
Rep Power: 811

coolant temp sensor is also called ECT (engine coolant temp) sensor or water temp sensor. this one is important for ecu function. the other one is a fan temp sensor that just tells the cooling fan when to come on if the coolant gets too hot. ect is under $50 and easy to replace without draining the coolant! all you do is unscrew the old one, unplug, and put the new one in. its the sensor near the thermostat housing facing up. the fan sensor is actually inside the round part of the thermo housing. ect sensor problems should trigger the check engine light and can cause issues because the car doesnt know when its warmed up. so it may be running rich all the time in warmup mode like it does when you first start the car and cause terrible mpg and possibly destroy the cat converter. i just posted a really detailed reply in someones thread about troubleshooting the sensor. you can test it before replacing, but sounds like that may be the issue.

 
Rep Power: 811

check this thread too

https://www.civicforums.com/forums/3...rk-lights.html

 
Rep Power: 0

Hey thanks for the info Gearbox. So I dont have a CEL on.. Is it safe to assume its the sensors and just go ahead and replace it?

 
Rep Power: 811

it may not always come on so idk. but i would test the sensor first before assuming its bad.

 
Rep Power: 0

How would I go about testing it? I still get a accurate (atleast I think its accurate) coolant temperature on my cluster.. I mean I know if I test it in cold and hot water it will tell me the temperatures. Could it be slow respons?

 
Rep Power: 811

its a very basic temperature sensitive resistor. ive never heard of slow response, usually it either works or it doesnt. you can try getting a few different bowls of water (ice, room temp, and hot) and see if the resistance changes at the terminals when you switch water temps.

 
Rep Power: 0

Okay, so I changed the sensor over a week ago and everything since has been pretty good. Although I dont do a lot of driving.. So I had no problems much untill yesterday when it did it again. Although it is better then it has been... So anybody lead me to what else could be causing a problem?

 
Rep Power: 811

i know old cars with bad main relays had this problem too. also if you have a small vacuum leak it might happen.

 
Rep Power: 0

Is there a way to check the main relay, and how do I check for a small vacum leak? I never hear any when im under the hood with it running.

 
Rep Power: 0

Also I wanted to describe the problem a bit better. The problem never happens when the engine is very cold like first thing in the moring. It always happens when I drive the car untill it is warmed up and then I park it for about 1-2 hours and the temperature gets just below the cold mark. Thats when it has a rough idle once I restart it. Also when it has the rough idle if I try to give more gas to cause it to stop nothing happens when I give it gas.

 
Rep Power: 227

Does your CEL work?

Have you inspected the spark plugs?

 
Rep Power: 811

does it still run rough when the engine is warmed up? if not, you could have a small headgasket leak that is causing coolant to seek into the combustion chambers and get the plugs wet. but once the engine warms up and burns the coolant away, and prolly seals the small leak, everythings fine.

 
Rep Power: 0

hey guys thanks for the response. To answer your questions, yes the CEL works. Atleast it did 8 months ago when I had to change 02 sensors. I guess i can check though. I have changed the plugs about a year ago, I think I am just going to take them out and put some NGK Irridium ones in. And I doubt its a small HGL I have only ever had to top up my coolant once over a year ago, about only 0.5L when I first bought the car. Over 30,000km put on since then.

So if it was to be any of those I would lean towards spark plugs... but dont know yet. Ill have to wait for a semi warm day and change them out.

 
Rep Power: 0

Hey guys so I went and scanned for any codes. There was no CEL on but I did get 1 code. The code was P0500: Veh speed sensor A malfucntion.
So something to do with a speed sensor malfunctioning? What do you guys think?

 
Rep Power: 0

I just found this thread this week and am experiencing the exact same problem with my 1993 Civic DX. Does anyone have instructions/pix on how to replace the ECT sensor? I am assuming that I have to drain at least some of the coolant before I remove it, correct?

Any help/advice would be greatly appreciated. These Civics are good cars but quirky when it comes to these starting/stalling issues.

Thanks.

Bill