Emission test fail Nuts.

[DaveT]

My 1993 Loyale w/3AT 4WD.  California version

Resealed engine installed, by me.  Custom stainless exhaust, by me.  Running a 180 degree Stant thermostat, the good ones.  .

 

It's been running normally.  Not burning oil at a crazy rate.  Heck, I had an engine that burned a quart per fill up, and it would pass.  More than once! 

 

Any ideas on what is a typical cause / first things to look at for high hydrocarbons emissions?

Has anyone heard of any method of testing for HC?   My biggest annoyance of the whole emissions thing is that I have to troubleshoot blind.
 

I'm going to attach my temp probes to check the catalytic converter tomorrow while driving. 

 

Test from 2 years ago - PASS:

Hydrocarbons = 20ppm  Limit 167 ppm

    CO              = .16%     Limit .89%

HP = 12.1

RPM  = 1985

Temp = 167 F

 

Test from today - FAIL:

 

Cruise

Hydrocarbons = 102ppm  Limit = 220ppm

           CO       = .78%      Limit  = 1.2%

   RPM = 2441

 

Idle

Hydrocarbons = 577ppm  Limit = 220ppm

           CO       = .54%      Limit  = 1.2%

   RPM = 923

 

Of course, just to "help", they changed the test form.  grrr.  But the main data seems similar.

[ihscout54]

Looks like a rich and high idle condition. Was the car completely warmed up for the test? Age of the O2S? Your a subavet so you know the ropes... Basics first, is there any missing at idle? Check for any vacuum leaks, including the pcv system. If its warmed up I wonder if its falling out of closed loop for the idle part of the test.

Start with the vac system and missfire diag. Since your readings are 2.5x the limit and the idle is out of spec, theres a good chance you could have a leak causing a miss.

Edited September 21, 2016 by ihscout54

[loyale1993]

Catalytic converter maybe o2 sensor? Is your egr working properly?

[DaveT]

Yes, but I don't remember running into this one before.

 

IT should have been up to temp.  30 minute drive, but then had to make a couple quick stops before going to the emission place. 

 

rich and high idle...  I should check the CTS....

 

Would a miss not be felt in rough running / idling? 

 

I know the O2 sensor can be off spec and not cause a code, so probably wouldn't hurt to replace the old one.  Haven't replaced one of those due to known failure in quite a while. 

Vacuum leak, ok, I know how to check for that.

[two85s]

Hey Dave, I've been through the CA emissions ringer with my 85 GL and both times, most recently, the Hydrocarbons were high.  There's a thread on here about it (cant find it).  Time before last ...so about 3yrs after failing, I checked EGR (was clean just slightly sooty) and learned how to test it with a finger.  Not the EGR.  Short story, ...the shop ended concluding I needed a new CAT, so we did that (my model has no O2 sensors) and then the wagon passed easily after $600 for testing, retesting, parts and labor. 

 

Last test ...last year, took to a test only shop (figuring the CAT was still pretty new since I don't put a lot of miles on the car) and it failed with high HC. 

So back to the same shop that tested and fixed it before (busy shop so had to leave it there about a week total).  They run it and get an idea of the readings (without doing an official registered test) and then know where to work.  EGR was functional, CAT had been replaced by them so they didn't think that was the problem. So, the mechanic said the problem was a simple valve ...that is what he called it.  I don't know the name or part number but it is located to the passenger side of the carburetor and sort of next to the carburetor where the vacuum hoses meet together.  After he tried sourcing it, he asked if I could source the part/valve?  I said not at all likely, so what he did is got it functioning again by soaking it in WD40 overnight an blowing it out with compressed air.  Then he "pre-tested" the wagon, saw good readings, tested it and got an easy pass after about $140 in labor and testing. 

 

My wagon burns a little oil, but idles nice and has no smoke, ...little 4 banger runs great (about 23mpg and 215K) and I know I'm not a "polluter", but CA keeps changing the testing to get the older non-exempt cars off the roads.  ...Ridiculous, for a good little car that is paid for and gets me places I need to go.  It's my property and the bi-annual smog stuff is a major pain.  Anyway, the mechanic said you don't always want to get a car real "hot" before a test because it depends on what the readings are and what your intentions are.  Hope this helps your situation.  Good luck with it. 

[DaveT]

Mine is SPFI. I think it has maybe one more time before no more testing. My 87 had its last time already.

[el_freddo]

I'd be looking at the O2 for sure.

 

Interesting how all that testing stuff works over there. We don't have it here but if you remove any/all of the anti pollution gear and are busted, the EPA comes down pretty hard on you and will throw the book at you!

 

All the best with it!

 

Cheers

 

Bennie

[Rust]

  In CT if they are 25 yrs or older they are emission testing exempt, looks like they caught  you right before the 25 yr deadline .    The last time I brought my loyale through I put some black tape over the check engine dash lights.  Ran the tank dry, then poured in a gallon of de-natured alcohol.  passed with flying colors.  I bet you could use coleman fuel also

Edited September 21, 2016 by Rust

[DaveT]

Would a wideband O2 sensor give me a reading I could use even if only in a relative way to tell when I've got things working right? I could install one along side the stock one. Not actually use it for engin control for the testing. also use my 2nd car as a reference to get good numbers.

[iceageg]

The denatured alcohol trick works pretty well.  I've had a couple friends that used it with great results.

[ihscout54]

Dave, I think the car has a problem that needs fixed. Its not a matter of tweeking to sneak it past or tricking to get through. The wide band could possibly be of some help, but expensive and likely not needed. Those limits they set are surprisingly forgiving and the car is way over. I bet u have a little miss thats spitting unburnt fuel at idle. There may be no noticeable roughness (especially at 1000 rpm) and it might take some real time at the tailpipe listening to hear it. We already know a 1000 rpm idle is outa spec.

I sorta doubt its the cat, at least at this point.

The only way it would be the EGR is if its not closing completely or leaking in some way creating a vacuum leak.

CTS - maybe

[DaveT]

I am not inclined to cheat it, I'd rather fix it. I'll have exhaust temps when I get home tonight, and I'll start checking for leaks etc. I have 60 days to get the free retest, so not a panic situation. The idle didn't seem odd on the drive to work today, but Ill have to put my real tach on it also, as I know the dash one may not be accurate at the bottom of it's scale.

[iceageg]

Dave, I think the car has a problem that needs fixed. Its not a matter of tweeking to sneak it past or tricking to get through. . .

 

Definitely find and fix the issue.  Getting it passed so you can stay registered is just a stopgap.

[ihscout54]

Emissions testing varies so much from place to place and by year of the vehicle. Its been years since ive had to pass one but I know they can be a PITA. In this situation tho (especially since the car is all stock and fuel injected) the test did exactly what it was meant to do and uncovered a problem which is causing waisted fuel and unneeded pollution.

Fingers crossed; u have a dirty air filter, cracked vacuum line or a loose hose clamp.

[DaveT]

Exhaust gas temperature near o2 sensor, 500 to 600 degrees F. After the catalytic, around 300. Not a good sign for the cat. It's dead. It should be a hundred or two higher.

 

Why it's dead? That's the other stuff to check, as mentioned above. I had a bad o2 sensor kill one many years ago.

 

The good thing about my custom exhaust is the cat is an $80 part from a tuner car shop, it replaces the 2 very expensive oem ones that are part of the pipes.

[ihscout54]

Can you try the test with the rpms elevated, say 2k and fully warmed up? If your cat is not part of the Y then you should test at the inlet in front and outlet in back. Not sure how accurate you can get with such a test. Tho the outlet is suppoed to be hotter when its working. if its the same in/out its not working and if its cooler at the outlet its plugged up. Better google that to confirm.

Any emissions issue such as a rich/lean condition or excessive consumption of any fluid will kill the cat. If its plugged up then you have other tests to do.

Since the only thing on the test that was a fail is high hydrocarbons at idle I still think your problem lies elsewhere. Could this problem have killed the cat?

[DaveT]

Oh, the temperatures were read while driving with moderate load.  Thermocouple probes clamped to the pipes.   I've used this setup before, so I have an idea of what to expect.  This system has passed more than one test since I built them in 2010.  I made 2, one on each of my wagons.

Oooh, no fluid consumption with the current engine, but this system was on another car for a good while with the engine that burned a quart of oil every tank of gas.  It passed emissions twice!  Then one of the heads began cracking, leaking coolant into the exhaust port on one side.  I continued running it while rebuilding an engine, and it got to the point where water would drip through at a rate that I had to add a regular size bottle of bottled water before every drive.  It was summer, so I didn't bother with antifreeze.   I also ran it with a zero pressure cap to keep the leaking down.  But wait.... it passed when I put it on this car 2 years ago...  or did I run it through emissions with it's original exhaust?  Damn, can't remember.  I probably put it on this car when I had to swap the transmission.  hmmm.  I guess all that doesn't matter, as it's dead for sure now.

 

http://www.dynahoedave.co.nf/exhaust.html

[ihscout54]

The good thing about my custom exhaust is the cat is an $80 part from a tuner car shop, it replaces the 2 very expensive oem ones that are part of the pipes.

The link you posted shows how simple cat replacement is with your system. Aftermarket converters arent known for their life span anyways. Your previous test numbers were lower all around, so maybe it was on there and working. Of corse that test does not show results for idle. Could that alone be the problem? Well since you are going to replace it I hope so.

[DaveT]

Hmmm.... I wonder. The temps vary pretty quickly with engine rpm and load.

 

I'll have to check the temps with the new one. Also put the probes on my othe car in the meantime, see what it's doing.

 

Yeah, that idle test is new.

[DaveT]

So far-

Going by tests in the FSM:

CTS looks ok.

Airflow meter test ok

TPS looks ok

 

Checked the spark plug wires, all look / measure normal.

Checked the plugs.  Light brown coating on all 4. 

Gap on the passenger side 2 about .039"

Gap on the driver side about ..060"  corrected to match the other 2.

 

Tested the cat on the identical custom system  my other car.  it isn't firing either.
I have the OEM exhaust &O2 sensor that passed on the car when I got it, so that will go on for the re test.

 

Idle speed seems normal for what I see every day, not sure why it would have been high for the test.

Since the new test that failed was the idle test, I wonder - the cat is dead, but it passes the cruising test anyway.  Would idle inherently make more hydrocarbons, and thus fail since the cat is not removing them?

[ihscout54]

I really cannot tell you for sure If the cat is 100% responsible for the excessive numbers at idle. You are pretty sure that aftermarket cat is DOA, it needs addressed. I will say there are many who brag of getting through such tests cat free, but Ive never tried it. The plugs were an interesting find. Is it possible the a/c was on during the test? Any added load during idle, maybe the inspectors toe on the gas or hand keeping pressure on the steering wheel?

For fun maybe a code scan. Does the silver Loyale ECM have the O2 monitor lamp? If so you could watch its function while sitting at idle. If its falling in and out of closed loop that might do some odd things.

I personally would want to know why the idle is/was high and Im pretty sure you have access to a decent tach. Confirm the idle situation and work from there. Any small issue would be most prevalent at idle; crappy plug wire, corroded cap n rotor, leaky injector, out of spec fuel pressure, evap/purge system issue, intake boot tear or cracks, any leak for that matter... On and on.

[DaveT]

The AC compressor is disabled, as I have not had time to work on it.   <--- strike that, that's the other car.   But it was not used by me, wasn't on when I got back into the car after the test.   It wasn't a hot day.  I'd hope that the testing guys would know not to try to run the AC during a test.  This place has been good in the past.

 

Can't say about the other possible test operator errors, while there is a video feed, you really can't tell what is happening exactly.

 

I just found some oil in the vacuum line at the 3AT vacuum modulator, so I will be testing that to see if it's leaking.

I

I'll look at / check the other ideas also.  Plus the PCV valve.

Edited October 9, 2016 by DaveT

[DaveT]

PCV valve was a bit dirty, but the moving part wasn't stuck.  Found another one, cleaned & checked it and put it in.

 

The contacts inside the disty cap had grey crusty stuff built up on them, scraped that off.  Center button normal.  End of the rotor had black crud.  Found a rotor in better shape, cleaned & installed it.

 

Drew vacuum on the Modulator, with clear line, so I could watch for oil.  Got some residual that was sitting in it, but not able to draw a continuous supply, or detect leakage.  It was odd looking, not the same red as the ATF, not the same darkness of the engine oil.

 

Going to put the known good exhaust system on it now. 

 

Only other sort of known unknown is that I'm running a 180 degree thermostat, instead of the normal 190 degree.  Would that make enough difference for the ECU to not go into closed loop mode?  How do I tell? 

[ihscout54]

Ive ran both thermostats and prefer the 19x but I noticed no difference in performance with either. The blinking led O2 lamp on the ecm is your indicator on closed loop status. If its blinking or on off erratically its in closed loop if its off its in open loop. Or so thats how i remember it. I cant say if the silver box on ur car works this way as my only experiance is with my SPFI swaps which were all the older black box types. I do know that my cars would fall out of open loop at long stop lights, and I liked the idle quality better in open loop. I eventually installed a heated O2 and that stopped.

You may have found your issue already. Did you ever get a tach on there?

[DaveT]

Didn't put the tach on it yet.  Wanted to get all the work / checks done before getting it all hot.  Just going by my long history with these, the idle hasn't been abnormally high consistently.  I was specifically paying attention to it after the test, and it would sometimes be pretty low, to normal.  Although, the difference between the limit & fail reading might be hard to tell "By ear" without an A/B reference.

 

Tuesday / Wednesday, I'll be taking it out for a drive, and stop to check Idle RPM when it's hot.  If it reads good, and no other noticeable weirdness,  ill take it back for the retest, right then.