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-   -   Oil Pressure Light On (https://www.civicforums.com/forums/237-mechanical-problems-vehicle-issues-fix-forum/370607-oil-pressure-light.html)

Wankenstein 07-05-2017 04:42 PM

Oil Pressure Light On
 
'95 EX coupe, B20B enine, M/T.

Had front of car up on jack stands for around 10 days due to delays modifying steering rack. Get it all back together, perform ECU relearn, engine idling rough and then a P0505 IACV code comes up. Unhook battery, clear code, let idle and after a minute engine stalls. Now oil light is on. Check oil and level is good (recently changed). Turn key to position to oil light on (not blinking) start car, oil light goes off and it idles for a few seconds and then engine stalls. Haven't started since and very concerned. Was running very well prior to steering rack job.

I will mention that this engine tends to near stall and/or completely stall when doing an ECU relearn. I just can recall if it's normal for the oil light to stay on after engine stalls? The oil light has not blinked at any time and does not come on during the brief time the engine is running. This may just be normal and I'm panicking. The P0505 IACV code has not returned and other than idling a bit rough, which I believe is due to incomplete ECU idle relearn, everything else seems okay.

Wankenstein 07-05-2017 06:53 PM

Re: Oil Pressure Light On
 
Looks like I panicked.. drove car home and no oil light. However, P0505 did return during driving. I pulled over and unplugged IACV and engine stalled. Plugged IACV in again, started engine and reset the CEL with the Hondash live data app (engine running). It ran better until I pulled into my home and it idled poorly for twenty seconds and then returned to normal. From past experience this engine seems to be sensitive to ECU relearn. It kept stalling earlier when I tried to perform one so I decided to just drive it a day two before attempting again.

On way to work tonight engine is running worse ..like it has a cylinder misfire (no CEL). Will do drop test on it tomorrow.
Engine running rough at idle and under load intermittently.

ezone 07-06-2017 12:37 AM

Re: Oil Pressure Light On
 
Red oil light (gravy boat light) on = no oil pressure.
Engine not running = no oil pressure.
Engine running longer than a few seconds, that SOB better have oil pressure.

Wankenstein 07-06-2017 02:59 AM

Re: Oil Pressure Light On
 

Originally Posted by ezone (Post 4726895)
Red oil light (gravy boat light) on = no oil pressure.
Engine not running = no oil pressure.
Engine running longer than a few seconds, that SOB better have oil pressure.

Oil light + battery light is on in position 2 before ignition.
Engine stalls during idle relearn due to hunting idle. When engine stalls, key in position 2.. red oil light and battery light on. No solid or blinking oil light when driving.

I have to do some diagnosing:
1) power balance drop test
2) spark test
4) fuel pressure

Also, spray contact cleaner in o2 connector and harness.

ezone 07-06-2017 12:15 PM

Re: Oil Pressure Light On
 

I just can recall if it's normal for the oil light to stay on after engine stalls?
Engine not running = no oil pressure.


Oil light + battery light is on in position 2 before ignition.
Before starting the engine, correct.
no oil pressure and alternator is not charging

When engine stalls, ===.. red oil light and battery light on
correct, no oil pressure and alternator is not charging while engine is not running


Yeah I'm kinda avoiding the stalling issue on purpose. Got video of the surging/stalling?

Wankenstein 07-06-2017 02:30 PM

Re: Oil Pressure Light On
 

Originally Posted by ezone (Post 4726923)
Yeah I'm kinda avoiding the stalling issue on purpose. Got video of the surging/stalling?

I can make one. This morning after work (night shift) on cold start it idled high as per normal for these engines and as it got near operating temp it and idled dropped (normal) it struggled to find a base idle. It would nearly stall aound 300 rpm then raise back up to 700-900 rpm and it did this hunting idle for a minute or so until it finally stalled.

On drive home it stalled once more at operating temp so I finessed the gas pedal to prevent it from stalling at stops. It has not stalled under load though I can feel some faint pulsing. Also, while keeping foot on gas pedal to prevent stalling at stops I tried to hold a steady idle around 1000 rpm and it would surge similar to symptoms of a dirty or failing/failed IACV but P0505 hasn't returned (so far).

When I got home it stalled again during idle. I performed a power balance drop test and I can hear good spark when I lifted each spark plug wire tip one at at time, and each cylinder did drop in idle when spark plug wire lifted. I held the TB pulley by hand at steady idle round 1500 rpm and it again surged up and down similar to IACV issue.

I wouldn't be surprised if this turns out to be a TB or IACV issue but, I'm trying to rule out other possibilities. At operating temp when IACV is disconnected the engine stalls. Should I pull the air intake hose and try holding my finger over the hole at the bottom of the TB that leads to IACV?

I intend to pull and inspect spark plugs, check mechanical and ignition timing. Would live data help (Hondash OBD 1 scanner)?

Wankenstein 07-07-2017 01:48 PM

Re: Oil Pressure Light On
 
1)Spark plugs: no fouling, gap is correct, no cracks or damage seen.
2) Sprayed several sensors including o2 with Deoxit electronic cleaner and lube..no change
3) After engine started rotated key in ignition slightly to check for possible ignition issue..didn't stall.
4) Checked ignition timing with timing light.. was in spec and a mark previously chiseled in.
5) Can hear fuel injectors firing with screwdriver to ear.
6) Adjusted TB idle screw but it didn't change idle speed at any rotation of screw/air flow. It was tightened all the way down before I tried adjusting it.

It's idling rough, car vibrates more than normal and is still stalling after running for a few minutes. The valve train seems to have more chatter than prior to steering rack repair. I haven't checked mechanical timing yet..need to read up on timing marks and how-to with DOHC. Intend to do a compression test and search for vacuum leaks. Which method(s) do you use to find vacuum leaks?

Would having the front end on jack stands for a long time possibly cause air in coolant system?

ezone 07-07-2017 05:09 PM

Re: Oil Pressure Light On
 
Does the engine have an EGR valve?

Wankenstein 07-07-2017 05:29 PM

Re: Oil Pressure Light On
 

Originally Posted by ezone (Post 4726994)
Does the engine have an EGR valve?

Doesn't have one that I can see. Did a search online and others are saying no EGR on JDM B20b.

I never touched the engine. I did remove the exhaust from front of cat converter to bottom of manilfold (cat back design) to remove the steering rack. In the tens days I had the car up on jack stands there was a lot of rain and humidity..worked on car in roof covered open air carport. Maybe a possibilty of water in gas? Thinking of adding 85% isopryl alchohol to gas and removing and flushing the fuel filter with isopyrl alchohol. Also, we have 10% ethanol in our gas in Florida..I don't think it sat long enough for ethanol to be an issue but I have seen it effect outboard marine engines in a short period of time.

Not sure if you recall that my car doesn't have an evap cannister or related solenoids and fumes just release to atmosphere through cut tubing that runs along the firewall. So, I don't know if condensation can enter this way?

ezone 07-07-2017 10:07 PM

Re: Oil Pressure Light On
 
EGR was just a thought.

You wouldn't have water in the fuel unless it rained directly into the hoses or tank IMO, and the Ethanol already in the fuel can absorb a little bit of water as it is.
Take a fuel sample in a clear jar if you suspect, don't just dump more alky into it.


You got a scanner device, right?
After sitting overnight, before running the engine, do the ECT and IAT values match pretty close?
What's data look like while it's surging? What's the surging look like?
Video of data list while listening to the engine surge?
Front O2 value?


As you attempt to adjust the IAB screw with it idling, the computer should be changing the IAC valve to keep the RPM consistent.
IF the passage for the IAB is actually clear enough to flow air.
If it's clogged up, it won't make any significant air volume change, so you could check those passages for air flow if you want.
Did you already go through this? I CRS.

Vac leak check......depends. Bionic ear, stethoscope, carb spray and scanner, fuel trim values, water, alky, propane.....
A speed density system will add fuel to compensate for air leakage, so the RPM will rise with a vacuum leak (until it reaches fuel cut rpm).....but if there is leakage at an individual intake manifold runner (IM gasket leak) it can act very different, single cylinder miss and stumbles may be noticed.

Wankenstein 07-07-2017 10:36 PM

Re: Oil Pressure Light On
 

Originally Posted by ezone (Post 4727009)
Take a fuel sample in a clear jar if you suspect, don't just dump more alky into it.

Okay.


Originally Posted by ezone (Post 4727009)
You got a scanner device, right?

Yes


Originally Posted by ezone (Post 4727009)
After sitting overnight, before running the engine, do the ECT and IAT values match pretty close?

Will check tomorrow morning


Originally Posted by ezone (Post 4727009)
What's data look like while it's surging? What's the surging look like? Video of data list while listening to the engine surge?
Front O2 value?

Will video tomorrow


Originally Posted by ezone (Post 4727009)
As you attempt to adjust the IAB screw with it idling, the computer should be changing the IAC valve to keep the RPM consistent. IF the passage for the IAB is actually clear enough to flow air.
If it's clogged up, it won't make any significant air volume change, so you could check those passages for air flow if you want. Did you already go through this? I CRS.

I haven't checked IAB for clogging..does it require removing TB or just removed screw and use a pick to clean?


Originally Posted by ezone (Post 4727009)
Vac leak check......depends. Bionic ear, stethoscope, carb spray and scanner, fuel trim values, water, alky, propane.....A speed density system will add fuel to compensate for air leakage, so the RPM will rise with a vacuum leak (until it reaches fuel cut rpm).....but if there is leakage at an individual intake manifold runner (IM gasket leak) it can act very different, single cylinder miss and stumbles may be noticed.

I'll try carb spray and smoke test with a cigar. It sure acts like it has a vacuum leak but, if so it has to be proven.

Do you know if there are timing marks on TB cover of a B20?
If I remove the valve cover, set first piston to TDC and both cams are at 12 o'clock position and cam marks face each other is that considered to be properly timed and can assume crank is timed correctly as well?
P.S. shown in video below at 21:00 minute mark:

ezone 07-07-2017 11:04 PM

Re: Oil Pressure Light On
 

does it require removing TB or just removed screw and use a pick to clean?
I dunno. I just mentioned it.

Do you know if there are timing marks on TB cover of a B20?
Crank pulley is normal TDC mark, to view cams marks you may need to remove the upper cover after you get the valve cover off. It's like 2 more bolts or something easy.

Look up how to time a 97-01 CRV engine

Marks should be like this
http://repairguide.autozone.com/znet...528026a61b.gif




P.S. shown in video
20:30 holy hell that alternator belt is trashed.

Wankenstein 07-08-2017 07:16 PM

Re: Oil Pressure Light On
 
2 Attachment(s)
Thanks for the diagram Ezone.

Mechanical timing seems to be good (pics attached). The exhaust cam may be very slightly off from 12 o'clock position and cam mark is maybe around one to three millimeters up from the top of cylinder head. Intake cam is dead on.
Did a valve lash check and all are in spec. all intakes at .005 All exhausts at .008

Did not yet:
Try to clean IAB passage yet
Do compression test yet
Check gas for water
Check for vacuum leak

Videos of live data and engine stalling. Apologize in advance for crappy narration and if doesn't include all the info you may need. I can record again if needed.

https://www.youtube.com/watch?v=oMFA...ature=youtu.be


ezone 07-08-2017 09:26 PM

Re: Oil Pressure Light On
 

cam mark is maybe around one to three millimeters
You can't adjust millimeters. As long as it's not a tooth out of whack, it's good.



Videos of live data and engine stalling
Oooh. I'm concerned with the primary O2 staying near zero.
It starts out at .99v, then 30 seconds later when you show the scanner again it's steadily dropping then you revved the engine up so I couldn't see what would happen with the O2 value.

I'd like to see it run from a cold start--and let it idle until it acts up and surges or stalls, with the scanner in view (clearly) showing tach, O2, and if it has it, short term fuel trim and long term fuel trim, and loop or fuel system status.

I'm thinking the stumble and stall might be associated with lack of fuel or overfueling, either one a response to the inactivity of the O2 sensor.
Gotta figure out---- is the O2 sensor telling the truth, or lying?

Watch for puffs of black smoke out of the tailpipe as it runs bad/stumbles/stalls.

More questions:
Is the exhaust manifold and first pipe (or collector) all stock 1st gen CRV?
If not, where is the primary O2 sensor located?

ezone 07-08-2017 09:43 PM

Re: Oil Pressure Light On
 
Also, didn't you say the O2 sensor is new? What brand?

Ever use silicone near the engine?

Wankenstein 07-08-2017 10:36 PM

Re: Oil Pressure Light On
 

Originally Posted by ezone (Post 4727063)
You can't adjust millimeters. As long as it's not a tooth out of whack, it's good.

Okay. I didn't think it was an issue but thought I should mesntion it.




Originally Posted by ezone (Post 4727063)
Oooh. I'm concerned with the primary O2 staying near zero. It starts out at .99v, then 30 seconds later when you show the scanner again it's steadily dropping then you revved the engine up so I couldn't see what would happen with the O2 value. I'd like to see it run from a cold start--and let it idle until it acts up and surges or stalls, with the scanner in view (clearly) showing tach, O2, and if it has it, short term fuel trim and long term fuel trim, and loop or fuel system status.

I'll make another clearer video tomorrow showing o2 in those conditions.


Originally Posted by ezone (Post 4727063)
I'm thinking the stumble and stall might be associated with lack of fuel or overfueling, either one a response to the inactivity of the O2 sensor. Gotta figure out---- is the O2 sensor telling the truth, or lying?

This engine has had a hunting idle since I purchased it. I'll ask the previous owner what brand he installed. He did say it was a relatively new sensor when I purchased it in February. My guess is that based on some parts he chose to use on this car that he may have cheaped out on the proper NGK or Denso sensor.


Originally Posted by ezone (Post 4727063)
Watch for puffs of black smoke out of the tailpipe as it runs bad/stumbles/stalls.

okay


Originally Posted by ezone (Post 4727063)
Is the exhaust manifold and first pipe (or collector) all stock 1st gen CRV? If not, where is the primary O2 sensor located?

Not sure...will ask seller. It is a cat back (EX) exhaust. Primary o2 sensor is located in front of cat or possibly resonator...may be straight piped? I haven't had the need to disconnect the secondary so, not sure if it has one.

Wankenstein 07-08-2017 10:45 PM

Re: Oil Pressure Light On
 

Originally Posted by ezone (Post 4727064)
Ever use silicone near the engine?

Unfortunately, yes...on the IACV gasket. When I removed the IACV a four months ago to clean it I noticed the gasket was very flat and stiff. I was concerned it may be a source of a vacuum leak. I called the local Honda dealer but they didn't have one in stock so, I used RTV black on the gasket. Even at that time I was hesitant because I'm aware silicone can effect sensors but, it seem like such a small amount needed that it wouldn't hurt.

ezone 07-08-2017 10:46 PM

Re: Oil Pressure Light On
 
Get under it and look? Snap a pic of the pipe and sensor?
I just want to make sure it's not a header with the sensor located in one single primary pipe (sensing exhaust from only one cylinder) instead of the collector where it is in the flow of all 4 cylinders.



Check brand stamped on the sensor?

ezone 07-08-2017 10:47 PM

Re: Oil Pressure Light On
 
Most RTV is "sensor safe" these days, but silicone spray lubricant is not.

Wankenstein 07-08-2017 11:35 PM

Re: Oil Pressure Light On
 

Originally Posted by ezone (Post 4727073)
Most RTV is "sensor safe" these days, but silicone spray lubricant is not.

Related pdf for Permatex Ultra Black: http://www.devcon.com/prodfiles/pdfs/fam_tds_371.pdf states it is sensor safe.

Well, three weeks ago I did spray a bit of WD-40 into the inside of TB flap mount hole .. pulley gear side not TPS side. WD-40 doesn't have silicone as far as I know. I forgot to mention I used Permatex RTV black on the TB side of the throttle boddy gasket two months ago. Again, got lazy and didn't feel like waiting for a gasket to be ordered. The existing gasket had a small tear so I put a very thin coat of RTV on the gasket. I'll order both the IACV and TB gasket.

Here's a thread I found concerning RTV and o2 damage: https://community.cartalk.com/t/how-...nsors/70388/26

"When silicone burns in the combustion chamber, it causes a silicon dioxide glaze to form on the oxygen sensor. This glaze causes the sensor to become sluggish when switching from rich to lean, and in some cases, increases the sensor minimum voltage on the lean switch. This causes the fuel system to spend excessive time delivering a lean mixture."

Wankenstein 07-08-2017 11:37 PM

Re: Oil Pressure Light On
 

Originally Posted by ezone (Post 4727072)
Get under it and look? Snap a pic of the pipe and sensor? I just want to make sure it's not a header with the sensor located in one single primary pipe (sensing exhaust from only one cylinder) instead of the collector where it is in the flow of all 4 cylinders. Check brand stamped on the sensor?

Okay. Will post in evening tomorrow.

Contacted seller and he said: NGK o2 sensor..doesn't know model number.
o2 sensor installed seven months ago.
No secondary sensor.
Exhaust manifold is from B20 CRV and the rest of the exhaust is an OEM '95 EX that incudes (cat-back) cat converter.

I'll inspect for o2 model number.

ezone 07-09-2017 11:43 AM

Re: Oil Pressure Light On
 
Nice thread link. Makes me wonder what my demeanor appears like on the forum sometimes. I keep running across threads from my year of nicotine withdrawals and want to delete them

Ok stock exhaust mani and front pipe, NTK sensor of some sort, that's enough.

I wonder if unplugging the O2 sensor will eliminate the symptom.

Wankenstein 07-09-2017 12:18 PM

Re: Oil Pressure Light On
 

Originally Posted by ezone (Post 4727101)
I wonder if unplugging the O2 sensor will eliminate the symptom.

I was thinking that as well..I'll try it. If it runs better disconnected can I run it that way for a few days until new sensor arrives?
Also, if the o2 is failing/failed is it due to RTV on TB and IACV gasket?

I've read that CRV's from years '97-98 use a different primary o2 sensor then years '99-'02 (4-wire A/F I think?). Seller told me the engine is a '99 JDM but I will try to find engine stamp to verify. He said he paid $125 for new OEM sensor and when I did a search online for '99 sensor prices were $200-$250.

If the o2 sensor isn't the issue does it point to a vacuum leak, failing TB or IACV as the most likely source?

Just checkd o2 sensors on amazon and looks to be the same upstream sensor for '97-'01 Part# 234-4011 unless there's a difference between USDM and JDM sensor types. Link:

ezone 07-09-2017 01:27 PM

Re: Oil Pressure Light On
 

If it runs better disconnected can I run it that way for a few days
Yes

is it due to RTV on TB and IACV gasket?
Not if you used the sensor safe stuff

read that CRV's from years
We only care about the sensor YOUR ECM needs. (and it's gotta fit the harness connector....what harness does it have?)
Are you using a CRV ECM?
I guess you probably should see what sensor is in it though.

If the o2 sensor isn't the issue
That's why I ask, is the O2 sensor telling the truth, or lying?
Have someone watching the tailpipe to check for puffs of black smoke while it's stumbling, and I need to know what's going on with the sensor voltage and fuel trim data at the same moments.

Wankenstein 07-09-2017 07:23 PM

Re: Oil Pressure Light On
 
Label on ECM (ECU): 37820-P75-A51 researching shows '95-'95 1.8 Acura Integra LS automatic transmission OBD1
My car has Integra LS manual transmission. Some clarification in this link: http://www.team-integra.net/forum/19...ification.html

I've read prior info that with these '92-'95 Civics with B20 engine frankenfu*k combination an OBD1 ECM is preferred.
Not sure of the harness used but it has a connector for the IACV and another (not connected) one for an FITV. This engine doesn't have an FITV.

Did a smoke test and no leaks seen. On cold start/idle sprayed TB cleaner on as many vacuum connections as I could reach (excluding bottom of intake gasket) and idle did not raise or lower,

Will post data video after it is available on Youtube.
No smoke from exhaust during stumbling idle.
When o2 sensor is disconnected idle stays around 600 rpm and doesn't hunt, stumble or stall. However, still excessive engine vibration. Switched on a/c compressor and rpm didn't rise.

I used my phone cam to locate part number on the o2 sensor. At the base is stamped: 4A29. I researched but nothing came up.

Not sure if it matters but when I connected the exhaust piece (bottom of manifold to front of cat) the round gasket that mounts between the front of cat and the distal end portion of that exhaust piece..I couldn't get those mated flat against each other. However, I don't think they are designed to with the gasket that's used. I tensioned the two bolt/springs similar to show in video at 0:48 second mark.

https://www.youtube.com/watch?v=Zl2C...ature=youtu.be

If that gasket leaked would it cause an idle/running issues?
When I had the steering rack out I left the above mention exhaust piece (o2 sensor bung in that piece) under car for 10 days..would moisture or possibly rust effect the o2 sensor?

ezone 07-09-2017 08:41 PM

Re: Oil Pressure Light On
 

Not sure of the harness used but it has a connector for the IACV and another (not connected) one for an FITV. This engine doesn't have an FITV.
Sounds like it's got the original Civic harness?


I couldn't get those mated flat against each other. However, I don't think they are designed to with the gasket that's used.
The cone shaped donut gasket is designed for flexible joints, thus the use of long bolts with springs for tension. If you have it too tight the flanges can snap off as the drivetrain moves about.
No, all this would do is be loud.
https://www.kseriesparts.com/graphic...1/IMG_6743.jpg




No smoke from exhaust during stumbling idle.
When o2 sensor is disconnected idle stays around 600 rpm and doesn't hunt, stumble or stall.
Sounds like the sensor may be telling the truth about it being lean, or it's dead.
With the sensor disconnected, does it run normally with normal expected power while driving? Or is it kinda anemic and down on power?

Got fuel pressure?


However, still excessive engine vibration.
Spritz a little carb cleaner spray into the throttle body and see if it likes the extra fuel.



Switched on a/c compressor and rpm didn't rise.
Is it supposed to rise? I expect it to at least stay the same. As long as it doesn't drop I'm not concerned yet.


.would moisture or possibly rust effect the o2 sensor?
If it's in the connector, hell yes.
If it got chemicals dripped on it, again yes
Brake cleaner sprayed on the outside of O2 sensor can ruin it, so can gasoline dripped on it, so it may have been affected by being exposed to more than just humidity.

Wankenstein 07-09-2017 09:41 PM

Re: Oil Pressure Light On
 

Originally Posted by ezone (Post 4727148)
Sounds like it's got the original Civic harness?

Agree


Originally Posted by ezone (Post 4727148)
The cone shaped donut gasket is designed for flexible joints, thus the use of long bolts with springs for tension. If you have it too tight the flanges can snap off as the drivetrain moves about.
No, all this would do is be loud.

Okay. Will back out bolts a bit to loosen tension.


Originally Posted by ezone (Post 4727148)
Sounds like the sensor may be telling the truth about it being lean, or it's dead. With the sensor disconnected, does it run normally with normal expected power while driving? Or is it kinda anemic and down on power?

I haven't taken it for a drive but will tomorrow


Originally Posted by ezone (Post 4727148)
Got fuel pressure?

says 38-40 psi on app and gauge on top of fuel filter


Originally Posted by ezone (Post 4727148)
Spritz a little carb cleaner spray into the throttle body and see if it likes the extra fuel.

Okay.


Originally Posted by ezone (Post 4727148)
Is it supposed to rise? I expect it to at least stay the same. As long as it doesn't drop I'm not concerned yet.

rpm's usually rise a bit on this engine when compressor is engaged and properly functioning o2 sensor. Doesn't drop.


Originally Posted by ezone (Post 4727148)
If it's in the connector, hell yes.
If it got chemicals dripped on it, again yes
Brake cleaner sprayed on the outside of O2 sensor can ruin it, so can gasoline dripped on it, so it may have been affected by being exposed to more than just humidity.

My money is on the brake cleaner that I sprayed on the steering rack to clean it while the o2 sensor/exhaust was already removed and underneath the rack. I should have used more caution and moved the pipe/o2 into the garage. I should have made it my 51st time I got up and down from under the car that day(s)...lol. That won't happen again. I did spray De-Oxit electronic cleaner and lube in the o2 connections a couple of days ago but, didn't help.

As I stated before and wrote other post about in the past..the engine idle has never been smooth on this car. Though it never stalled previously it did have an intermittent hunting idle. Has issues starting on inclines and declines. So, I'm wondering if the correct o2 was installed or is there a correct o2 sensor for this engine, ECU, harness, transmission combination?
Any way to find proper o2 sensor based on ECM model or will just have to pull it and hope numbers show?

Wankenstein 07-09-2017 10:56 PM

Poor Idle and Stalling
 
Live data vid. Aplogize for out of focus filming.

Upper Left: Revs
Upper Middle: o2 voltage
Upper Right: Primary o2 heater
Lower Left: ST o2 correction
Lower Middle: LT o2 correction
Lower Right : fuel flow (gal.hr)


ezone 07-09-2017 11:47 PM

Re: Oil Pressure Light On
 
I'm seeing O2 stuck near zero volts, and Long Term fuel correction at (damn thats fuzzy) 18.6% ?

Short Term fuel trim (lower left corner) suddenly becomes active at 1:53....shoots to over 40% by 2:12, 45% @2:20, still no change in O2 voltage, still stuck low.
All the positive fuel trim numbers mean the computer is adding extra fuel to its base injection calculations as it tries to elicit an electrical response from the (dead) O2 sensor.
This is the point I'd expect some kind of black smoke from the exhaust, but if you have a working cat it might eat the extra fuel and smoke.

Watch your fuel trim numbers when it stumbles.

@2:25 the STFT suddenly clicks to 3% and the engine stumbles badly. That's why it's stumbling so bad, it's the computers strategy.
(if you had displayed "loop status" it probably would have clicked briefly to open loop.)
That sudden fuel trim drop was the computer deciding it has maxed out it's adaptive fuel limit, then it is suddenly taking away all of the extra fuel it had added as it clicks to open loop, engine is suddenly starved lean and running becomes unstable.
Still no O2 response.
Add fuel again, ST shoots up again right away. Then suddenly drop fuel and stumble.
Repeat at regular intervals....


Something strange is that the sensor begins to respond when you rev up the engine. Makes me wonder if the sensors internal heater isn't working....but you'd probably have a code 41 or 48 if that were the case.

======================
Based on what I saw during idling, I'd say to replace the O2 sensor,
pull battery cable or pull fuses to dump learned trim and adaptive values, hopefully that will get LT value to reset to zero.

==================

It's just a normal O2 sensor, get the one for the old civic that will match your harness and ECM needs. Take your old one to the parts store and make sure the connector and wire length match. (our biggest issue with aftermarket is incorrect heater element resistance for a given application)

Don't put anything in the connectors either. Hopefully whatever you used won't hurt it. All but the simplest single wire sensors literally "breathe" air through the wire, (O2 sensor operates on a comparison principle) wicking their fresh air sample through the wiring harnesses and contaminants (silicone for one) can enter through the wiring.

Wankenstein 07-10-2017 12:26 AM

Re: Oil Pressure Light On
 

Originally Posted by ezone (Post 4727159)
Based on what I saw during idling, I'd say to replace the O2 sensor,pull battery cable or pull fuses to dump learned trim and adaptive values, hopefully that will get LT value to reset to zero.

It's just a normal O2 sensor, get the one for the old civic that will match your harness and ECM needs. Take your old one to the parts store and make sure the connector and wire length match. (our biggest issue with aftermarket is incorrect heater element resistance for a given application)

Don't put anything in the connectors either. Hopefully whatever you used won't hurt it. All but the simplest single wire sensors literally "breathe" air through the wire, (O2 sensor operates on a comparison principle) wicking their fresh air sample through the wiring harnesses and contaminants (silicone for one) can enter through the wiring.

Thanks Ezone. Sorry for the fuzzy vid.
I wont use the DeOxit anymore..though I have used it on my old '98 EX on the speed sensor harness and it brought it back to life without issues. I've used it on tube amps and TV circuit boards too.

I'll purchase a Denso or NGK OEM primary o2 with correct length. Denso part# 234-4099..$30 at Wal-mart (lol)
This Hondash unit seems to be paying for itself already. Come to think of it I have a newer o2 sensor on hand that someone (not me) wrongfully installed on my mom's 7th gen before she purchased it that kept throwing a CEL. I changed it out with the correct one a couple years ago and no CEL since. I'll research the part numbers and see if it will work.

A few good things came out of this.. I now know: Valve adjustment is good, mechanical and ignition timing is good, TB looks/feels to be tensioned well, seems to have no vacuum leaks, learned what not to do with o2 sensors. Thanks again and I will keep you posted. I might go ahead and do what I mentioned to you in the PM.


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