Perplexing Situation

[stp71]

Hi,

I'm new to this forum and have a question with regards to my 1995 Honda Civic DX. At best, I'm only a youtube mechanic and I would be extremely grateful if someone could share some wisdom regarding how to correct an issue I'm having with the car. Here's the situation:

In short, while the car is idling in park, the engine will "choke" every 5-15 seconds in a random fashion. By 'choking' I mean that it seems like it is starving for fuel for a second or so and then recovers and runs "fine". Strangely, when I turn the air conditioning ON, the "choking" is essentially eliminated! I've heard about decreased power/efficiency from having the AC on, but never an improved condition from having the AC on. I should also note that I've just recently completed a long list of standard tune-up service items to the car (i.e new plugs and ignition wires, new distributor cap/rotor, cleaned the throttle body, new pcv valve and hose, added Lucas fuel injector cleaner, new fuel filter, changed oil and filter). In addition, I've also recently had the radiator, O2 sensor, and timing belt replaced.

None of the above items seemed to fix the issue (actually, the first time I noticed a choking issue was after the radiator was replaced.....that's why I replaced the o2 sensor because I suspected that the mechanic bumped it with the radiator installation).

Sorry for the long-winded post, but I had a lot of history to unload.......thanks in advance for any help you could offer!!!!

Scott

 

[xxBLOOD88SHOTxx]

Is this all the time or when it's cold or warmed up?

Is it only an audible noise or do you feel the car vibrating or anything like that?

Do you feel any sort of power loss when driving it? Like does it bog at a certain RPM?

How long since you put the Lucas fuel cleaner in it? Have you ran a full tank through it?

 

[lethal6]

Is this all the time or when it's cold or warmed up?

Is it only an audible noise or do you feel the car vibrating or anything like that?

Do you feel any sort of power loss when driving it? Like does it bog at a certain RPM?

How long since you put the Lucas fuel cleaner in it? Have you ran a full tank through it?

All very viable questions. We need more information.


Also in the future please put the problem you are having in the title of the thread, what you have now doesn't help anyone especially you. Most people will just move on by a lazy title instead of coming in to help mostly on the fact that they have no idea what you are asking for and don't put the time in to find out. If they know what they are getting into from the start, they are more likely to wander in and give their advice. This is a benefit for you and makes it easier for future searches as well once this thread dies out and becomes part of the archives.

 

[stp71]

Engine "choking" while idleing in park

Thanks for the questions and feedback...point well taken with regards to keeping the title more descriptive...will do.

I've replied below to the questions asked by xxBLOOD88SHOTxx :

Is this all the time or when it's cold or warmed up? - happens both cold and warmed up.

Is it only an audible noise or do you feel the car vibrating or anything like that? - I feel the car vibrating along with the audible noise

Do you feel any sort of power loss when driving it? Like does it bog at a certain RPM? - No, I don't feel a noticeable power loss while driving.

How long since you put the Lucas fuel cleaner in it? Have you ran a full tank through it? - the Lucas cleaner was put in at about a half a tank and I've since used that gas and filled up again....just a little ways into the new tank.

Thanks again.

 

[xxBLOOD88SHOTxx]

Did you gap those plugs when you put them in? Are you noticing any loss in MPG?
What kind of noise do you hear? Like a small popping noise? Where do you hear it coming from (like out the exhaust or in the engine bay)

I would reset the ECU and check the plugs first. Then ignition timing and fuel pressure and mechanical timing last.

Meanwhile, take note of your MPG after this tank is gone through, timing issues from either ignition or mechanical will always effect your MPG. Hell, you may even of just got a bad batch of gas or something. In any case, doing all the things I listed above is just good maintenance anyway.

 

[HeX]

Did you gap those plugs when you put them in? Are you noticing any loss in MPG?
What kind of noise do you hear? Like a small popping noise? Where do you hear it coming from (like out the exhaust or in the engine bay)

I would reset the ECU and check the plugs first. Then ignition timing and fuel pressure and mechanical timing last.

Meanwhile, take note of your MPG after this tank is gone through, timing issues from either ignition or mechanical will always effect your MPG. Hell, you may even of just got a bad batch of gas or something. In any case, doing all the things I listed above is just good maintenance anyway.

Please verify if you gapped the spark plugs to .44. Also, specify what gas you use. If you happened to fill up at a crappy gas station, that alone may be the issue. Drive it to nearly empty then refill with Chevron. They have the best additives on the market. If it still has that issue after a Chevron refill then it wasnt the gas and you can go from there.

The fact that it a constantly intermitent issue leads me to believe its a sensor. The better the details we receive the closer we'll get to helping you solve this.

By the way, thanks for attempting to share details in your first post. Not enough new members do so.

 

[stp71]

Thanks everyone for trying to help me out.

Regarding the plugs, I didn't check them personally, but the guy at autozone did check that they were pre-gapped to the correct specification before I bought them. Besides, the problem was more or less the same before and after replacing the plugs, so I'm inclined to think it is not that.

Regarding the noise, it is not so much a noise as it is just a rumbling sound associated with the engine seemingly starving for fuel every 5-15 seconds or so.

Regarding the gas, my mechanic told me that the station where I usually fill up is good stuff, but several tanks ago, I did fill up at a station he told me was not good gas.

Do you guys think it could have something to do with the fuel injectors? Would that produce this "random" choking or would that produce more of a general rough idle?

Also, somebody mentioned a sensor above. As I mentioned earlier, this whole problem started about a day after my mechanic replaced my radiator. I thought that that had to be more than a coincidence, but I have no idea how replacing a radiator could produce the symptoms I'm getting. The only thing I could think of was that perhaps he "bumped" the 02 sensor which is right by the radiator, but I replaced that and there is no apparent difference in performance.

I may need to just take the car into the mechanic or perhaps even the dealer for diagnosis, but I'm hoping not to have to do that!!.

Thanks again for all the help!
Scott