hygienejesus

​Looking for some guidance here.
98 Civic LX. approximately 165k miles. I bought it about 6 months ago.

This issue has started fairly recently but seems to be getting more frequent.
At completely random and infrequent times, the car will stall at low RPM (slowing down to a stop/while idling). I can usually restart it easily after it stalls, but it will often stall/bog down a few more times before it stays running. There will also be times while driving at different speeds (usually 60mph+ as I mostly do highway driving to/from work everyday) I can feel the car "bog" or "chug" if you will. I'll be on the gas, car is pulling at about 3k RPM or so, and you can hear it cut out for a split second and then come back on. It may do this once in and not again for the reset of the ride - it may do it 3 times in a minute and continue every so often. Usually if I feel this and then come to a stop, thats when the car wants to stall.

SOMETIMES it wants to stay running at a stop if I keep giving it gas - I've had to put it in neutral at stops and give it gas to stay running to get it home. This doesn't always work, but seems to most of the time. Unfortunately, usually by the time I get it home, it ends up running fine. ???

This throws no engine light or codes (and yes the light does work) and it happens so randomly that I can't get anyone else to witness the issue and give me any other ideas.

What I have already done (some of this was just part of regular maintenance since I bought the car, some was to attempt to fix this issue):

New air filter
New spark plugs and wires
New gas tank (I don't think this is necessarily related at all - old one was leaking so it needed replaced. Just throwing it out there!).
New fuel pump
New fuel filter
I also ran some Seafoam through the tank (before installing the new pump/filter).

What I have not done yet but intend to do:

New distributor cap and rotor. I have the parts but have no changed them yet.

What I am pretty confident that it is not:

Ignition switch. I don't know for sure, but from videos I have watched, you can usually just jiggle the key/assembly and the car will stall? This does not happen.
Plus I don't know why giving it gas would sometimes keep it running if it was an ignition switch.


Anyone have any ideas?

Thanks in advance.

Forgot to mention in my original post - I also cleaned the throttle body and IACV when this problem first started happening.

Former User

Does the charging system warning light in the cluster turn on or flicker?

hygienejesus

No it does not.

Just happened pretty bad a little bit ago. Started chugging/cutting out but stayed running. Got it to stay running by putting it in neutral and giving it gas. I was waiting to make a left turn on to a road with a center/turning lane - bogged down and died as I was pulling out. Managed to get it to the center lane and get it started but it continued to die. Had to restart several times and keep giving it gas. Eventually got to to stay running with RPMS up, dumped it into Drive and was able to pull into the driving lane and get it back to my work, but of course it is running fine now and wouldn't stall in the parking lot while I left it idling.

hygienejesus

Does anyone have any tips here? Thanks.

Former User

^

chrysler kid

Check main relay above ecu

Also lubricate throttle body spring on throttle body unit. My lx was doing the same thing through a drive through almost like it was a bad idle air control valve but it was just apparently the throttle spring sticking. I'm guessing it was just closing too quickly for the idle air control valve to kick in. I used wd40

You should also clean out the idle air control valve to be sure it's not that as well

hygienejesus

Cap and rotor needed changed, but this did not help.

Former User

What brand ignition parts? Plugs properly gapped?

hygienejesus

Cap/rotor were Beck Arnley. I don't remember what brand of plug wires - not OEM tho.
Plugs were gapped properly when I installed them, which was the day after I bought it.. That would have been about 5-6k miles ago.

I was driving it yesterday and everything was good for about 45 minutes, then I felt it bog/cut out while doing about 35mph but it stayed running. I parked it for about 30mins, then drove again and it began to do the same thing after about 5 minutes, then it died on me when I came to a stop sign. It seemed to not want to start unless I pumped the gas. I turned the key and it was cranked but wouldn't start, so I started pumping the gas and it seemed to want to start after I did this but wouldn't stay on. After a few tries I was able to get it to stay on, keeping the RPMs up, but I was on a busy rode trying to get it out of the way when this happened so this may have been more of a panic move (car may have started eventually without giving it any gas but I didn't try it long enough to see). Once I was able to get it started, I was able to keep the RPMs up and made it home without it stalling again, and of course it idled just fine and stayed running as soon as I stopped in my driveway.

Former User

For testing purposes, if you unplug the primary O2 sensor, is the problem eliminated?

hygienejesus

I will give it a try in the next few days and report back. Thanks

fonkernuckle

iTrader: (5)

I would check fuel pressure at idle and at 3k rpm and if thats ok then do a injector leak down test(I think that s what its called- you hook up a timer type device device costs like one hundred something on amazon and it in conjunction with the fuel pressure gauge it shows how well the injectors are working individually ,info on intenet.. I would look at fuel trims with a code reader that reads live data, if unfamiliar with them there is plenty info on internet.Also familiarize yourself on the readings that a good o2 sensor should be on live data these info will five you a clue as to what could be going amiss test at idle and revved up to 3k.. You might have a map sensor issue or vacuum leak.Another thing I would consider would be the ingnitor or coil going.Just what I would do my 2 cents.

hygienejesus

Keeping in mind that this problem has been very intermittent so I can't say for sure, but early results seem to indicate that this has helped. I was able to unplug it and drive it for about an hour and 10 minutes yesterday with no problems.

Former User

If this^ holds up, replace the primary O2 sensor.

chrysler kid

Good call Ron

You should also remove the head shield on the exhaust manifold or header, to see the area around the 02 sensor bung to inspect for any cracks. There could be some hairline cracks that are letting exhaust gas when the manifold is hot that can confuse the 02 sensor readings

hygienejesus

Going to drive it some more this weekend to make sure. Will check that out as well. Thanks again!

hygienejesus

Well well, car continued to run fine without the sensor connected so I ordered a new one that came in Saturday.
Yesterday, went out to prep for taking the old one out. Stupidly I first decided to cut the wires on the old o2 sensor so I could try to get a deep well socket on it. My heat shield was kinda busted and missing from around the sensor so I didn't feel the need to remove it at first, but after trying to get a better angle at the sensor I decided to take it off, and look what I found...

Crack doesn't go all the way around so I am going to try to repair it with my TIG welder but not sure how it will work. If it fails, I'll be junkyard diving or maybe I'll just get a cheap stainless set online or something.

Thanks to everyone for pointing me in the right direction. I appreciate it.

chrysler kid

Yeah that is the typical spot for the crack. You can try to weld it or jb weld it but expect only to get another 20k miles before the fixed weld cracks again

Former User

No worries. The O2 sensor was clearly toast anyway and needed to be replaced.

Were you experiencing low gas mileage?

hygienejesus

Yeah thats what I figured. Looks like a new set may be in order.

Actually yeah, it seems like it has been getting worse lately now that I think about it. My gas gauge is a little screwy once it gets below half. I'm always worried about running out so I always fill it up when I get near half tank, but it seems like I've been filling up more and more frequently.

Former User

The cracked header likely caused the engine to run rich, causing the death of the O2 sensor. What's unexpected is that the crack did not trigger a running lean CEL code. Perhaps the exhaust leak was very small.