phoenixe1123

I've never posted here but this is the site that gave me the information and confidence to do my head gasket and timing belt 5 years ago. Fast forward to 2018 and I have a new to me 2002 civic ex with 140k so I decide to do the clutch and timing belt. It went ok, I had one bad motor mount and accidentally bent my exhaust ( I have a donor car and was able to scavenge the bent pipe from there). Well, right after everything seemed fine car ran well, clutch functioned, and I was happy.
Then it began with the check engine light, 3 codes. The electronic load detector and both o2 sensors high voltage. Then the light went off and came back I ended up replacing the ELD and it went away only to be replaced with an odd loss of power in the 2-3k range where it would just stop, this could be remedied at first by taking the car out of gear and putting it back in gear while rolling and occasionally stumbling at idle would accompany this condition but it would only happen for a few seconds and after the ELD change it had stopped.
So about 600 problem free miles I decided to take it on a 3hr trip, 2.5 hours in I'm pulling onto the highway and sudden loss of power, pull over to the side and it dies and won't start. So I got it towed to a mechanic 2 hours later and he's ruled out fuel and spark. Not being able to pay any more for his 80hr services I was able to limp to Walmart where I pulled the timing belt found it was about 2-3 teeth out of time. I set the timing put it back together and the car runs beautifully and I drive it 2.5hrs home and another hour to a friend's house with no issues.
I go out the next morning and almost immediately there are issues rough idle wants to die no power. so I pulled it apart again and replaced the new belt and tensioner with another new set and it ran fine till the next moring.
Now after being in there 4 times 2 belts and 2 tensioners I'm left with a car that starts in the morning and is fine until it tries to idle below 1k or I try to drive and hit the 2-3k range where it will lose power sometimes(in and out of limp mode) then it settles down and I am able to drive albeit with incredible anxiety. Also, the same 3 codes keep coming and going (ELD, and both o2 sensors high voltage) I am now home and do not plan on driving the car until I figure this out if I can.
I'm looking for any ideas I plan on pulling the timing again but having already been down that road I don't expect it to solve it but maybe I missed something any help would be greatly appreciated.

ezone

Here's some ides that popped into my head as I read your post.....


1)
Manual trans.......
Every time you've taken the timing belt apart, are you finding the timing belt has jumped a tooth or more?
It's jumped teeth again this most recent time too?

If you park the car on a hill and leave it in the wrong gear, the crankshaft can be forced to turn backwards as the car creeps downhill and THAT might be what's causing it to mysteriously jump time.
If you are facing downhill, leave it in first gear.
If you are facing uphill, leave the car in reverse.
The idea is to make sure the crankshaft will turn in the direction of normal rotation if the car creeps down the hill on its own.

And set the handbrake a lot harder so it absolutely cannot roll on its own.

That, and the installation of the tensioner pulley.....if it wasn't set up correctly the stop might be far enough out to allow excess travel of the pulley, which can allow enough movement for the belt go slack and jump time as the crank rotates backwards.

Are you using a Genuine Honda tensioner pulley and spring kit? Aftermarkets are a crapshoot, far too many extremely premature failures, some even poop the bed before the next oil change. Several people have posted about cata$trophic engine failure$ (bent valves) as a result.

2)
If it has been run and driven with the timing belt out of time, it's possible the catalytic converter became damaged due to the poor running condition of the engine.
The computer can't do a self test on the cat right now because it's got O2 sensor related codes, so if those are solved then the computer might then be able to do a cat self check as you drive (see OBD2 readiness monitors).
One could do a backpressure check to confirm this, or, you said it's an EX so the cat is behind the engine and you could disconnect the cat (run open pipe) and see if performance is restored. (just as a test, because it's gonna be obnoxious loud)

3)
ELD is a common failure but that code alone that shouldn't turn on the CEL, and there's a bulletin about it being available by itself from dealers.
Did you get one from a dealer, or what? Is it good?

The ELD is powered by fuse #4 in the engine compartment fuse box.
The alternator also shares the same fuse.
So do the EVAP system solenoids....and cruise switches, and VSS, and.....


and guess what else, both O2 sensors share the same fuse.
4)
Did the O2 sensors get replaced? Did you use the OEM brand it originally came with (NTK or Denso)?
What exact codes does it set for the O2 sensors? If it's P0135/P0141 it could be related to that fuse mentioned, or if discount sensors were installed they might be incorrect for the application.

phoenixe1123

Thank you I appreciate the response.


1. yes it is a manual, but it is parked on fairly flat ground at most times. The belt and tensioner are aftermarket so that may be it but I'm kind of scared to drop any more money and wind up with the same problems. I'll probably order a oem set today, if worse comes to worse i can use it if i have to swap the engines. The tensioner at least to my knowledge was installed correctly twice the other two times (walmart parking lot and my buddys house) I did not have access to my torque wrench so i did my best guess. If the valves are bent i luckily still have the engine i did the first timing and head gasket on slightly higher miles but it ran when i pulled it. how would i know if they are would the engine noise be noticeable because when it is running it sounds right?

2. That was a thought I had when i got stuck, i pulled the spring bolts from the header to the down pipe with no change in the issues i was having at that time.

3. The ELD was another donation from the parts car (good at time of demise) ill get a new one when I order the oem timing belt. The exact codes as of today were P1298,P0138 and no cel. Could i have screwed up the computer? I haven't really given the o2s much thought because I've been so focused on the timing issues.

ezone

I was tossing out some likely scenarios that could cause a timing belt to jump, even though it's all new.
Possible tensioner spring too weak?

You have to figure out the real cause of the problem. You really NEED to figure out what's causing it before it becomes a huge engine shaped paperweight.


-----

If the timing belt only jumps one or two teeth it's not gonna bend valves...but it will run like crap while it's out of time.

If it jumps more than about 2 teeth the ECM can shut the engine down when it sees the cam-crank signals out of sync. It will shut down at 2 seconds time if it does this.

If it jumped more than about 3 or 4 teeth, that's getting dangerously close to bend territory. I don't ever want to find out first hand exactly how many teeth out of time it takes to cause real damage.

If you spin the cam or crank wrong with the belt off, of course you can bend any valves that were open. It will then run like crap and have low or no compression wherever the bent valves are.

If you put it back in time and it runs smooth again, you didn't bend valves.

-----

P0138 is REAR O2 sensor high voltage.
Is there a code for the front O2 sensor?

Does the code stay away as long as the engine doesn't jump time?

phoenixe1123

I've since stopped driving it until the new belt and tensioner arrive, but the spring was new OEM because the aftermarket kit didn't contain one(should have probably stopped there). I plan on doing a thorough (best of my ability) inspection when I take it back down and while I was reading I saw a few things to check. Like the spacer between the crank gear and the seal, I changed while I was in there.

I don't think its been more than 3 teeth out but who knows. To be honest I hadn't been watching the codes to closely and only pulled them when the CEL came on but when I was 3 teeth out there was no light but there had been one the day before. yes there was a code for the rear but it wasn't present when I checked today I believe it was the p0132

mikey1

going by all of this i would question your work and installation procedures, this sound like installation errors to me....no offense

there is a certain procedure you need to follow when mounting a new tensioner.....did you do so?

phoenixe1123

Hey Mikey to tell you the truth id have to agree with you if i hadn't already done it on another engine with no issues but Ive been blessed with a 5th chance to get it right so ill see what i find in there this weekend

GusBuz

If you havent already, download the shop manual. It shows the installation procedure for the tensioner, plus a whole lot of other useful info for when you might need it.

phoenixe1123

Well, I did the belt again yesterday. I had to move it to a better work area and was greeted with the same issues as described in the first post. I pulled it down expecting to find it at least a tooth out... it wasn't all timing marks were on point. I redid the timing with the OEM kit because I was there and I went through the full tensioner procedure. Put it back together started it up let it run 10 mins, shut it down, restarted it, and took it for a ride ran fantastic no problems. Then this morning I was greeted with the same issue the dying under 1000rpm and weird loss of power that went away after I took it for a ride it idled fine.

It is still pulling the ELD code and I will assume the o2 codes (hasn't made it through the checks yet) I'm waiting on the ELD to make it here, forgot to order it with the OEM timing set. I am hoping that taking care of the codes will solve the issues but if not all advice is appreciated.

ezone

Which issue was that, specifically? (first post was quite busy)

So timing belt had not jumped any teeth?

How long after startup did this happen? Less than a minute?
How long did this event last? 10 seconds?


Unplug the O2 sensors and drive it through the same scenarios as before....see if symptoms go away

phoenixe1123

the issues it seems to happen on cold(first start of the day or after several hours) starts. it will start out at about 1500rpm and slowly drop rpms after about a min or so till it dips below 1k and them it'll stumble almost die and catch itself this happens a few times till the computer catches on and keeps it above 1k I attempted to drive it and at first was met with the loss of power I was associating with limp mode.

Correct this Timing belt and tensioner had not jumped teeth but the one that was in it before definitely( the fiirst set) had

I could try that tomorrow morning and report back the car is running great right now and hasn't had an issue since the above happened on the first start up

also, i have since swapped the ELD

ezone

I've encountered some of these that would make the car "fall on its face" for a very short time, then several seconds later it goes back to normal like nothing unusual happened at all.

Ya, unplug both sensors and give it a drive from cold again, see if it still acts up. The CEL will come on because they are unplugged, ignore it for testing purposes.

Then tomorrow test it again with only the front (primary) sensor unplugged.....
I've seen the front sensor fail (sometimes without any codes) cause similar complaints and unplugging it is quick easy way to prevent the computer from being influenced by incorrect readings.



I think we all were expecting it to be found out of time again LOL

phoenixe1123

If it is the o2s and the timing was an isolated event (bad part?, over torqued tensioner?) It would fit because I had to swap the exhaust from the donor car which I did without changing the o2 sensors. They were good but that was before the exhaust sat around for a year or 2.

Is there a difference between 02 ex and 03 ex o2 sensors?

ezone

Same from 01-03.

phoenixe1123

Sorry it took so long to reply works been hectic

I drove it for a couple days till the computer cleared its checks and no codes or CEL but still the same issue on cold starts. I took Ezone's advice and unplugged the front o2 sensor this morning before start up and the problem appears to have disappeared. Guess that means its time to change them.

I wonder why it would cause the engine to stumble while cold, could the heating element have failed without throwing a code?
I am a little confused from reading around is the upsteam sensor on and ex and air/fuel sensor or a o2 sensor?

ezone

If you have a scanner that can display live operating data and its update rate is much quicker than 2 seconds you can watch the sensor and fuel trims in action......during the stumble you'd see the front (primary) sensor stuck at a value and the fuel trim goes to an extreme as a result. The stumble occurs when the skewed trims have made the mixture too rich or too lean.


For all 1.7 engines in any trim level:

Model years 01-03 used standard O2 sensor in both locations.

For model years 04-05 the primary sensor is an AF sensor.

phoenixe1123

Thank you for the explanation. I have ordered a set of NTK sensors (24291,24283) and I'm hoping everthing will go back to normal once their installed.

Thank you for all your help Ezone.

ezone

I should have recommended....pull out the original sensors (if necessary for cleaning on a wire wheel) and locate the brand name on each and replace with the exact same brand(s) the factory installed.

NTK and DENSO were the original suppliers, and usually there aren't problems with changing between those two brands, but if it doesn't work right keep that in mind. NTK (NGK) and Denso each have their own websites you can look up your sensors on.

The cars are fairly simple, but sometimes damn finicky.