Welcome to the all new Geo Metro Forum. We hope you enjoy your visit.You're currently viewing our forum as a guest. This means you are limited to certain areas of the board and there are features you can't use and images you can't see. Registration is simple, fast, and completely free. If you're already a member please log in to your account to access all of our features: Join our community! |
| Need to shave 20 ppm more from hydrocarbon emissions; Failed Virginia emissions test | |
|---|---|
| Tweet Topic Started: Sep 25 2013, 07:41 PM (6,502 Views) | |
| ascensions | Sep 30 2013, 01:54 PM Post #46 |
|
Je conduis une petite voiture.
![]()
|
This may be your entire problem? What is factory? Mine is 5 degrees. Here in NC they check to make sure you're within 2 degrees of the hood sticker. I always set mine to 5 before going in, and pass so well I could breath the exhaust. Then I turn it back to 10, afterwards. Set it to 5, use some Techron Chevron- and I bet you'll pass. |
![]() |
|
| metromizer | Sep 30 2013, 03:17 PM Post #47 |
![]()
|
I went through the same stuff with a well-worn, oil consuming Toyota 1ZZ engine a couple years ago. I just needed to get past one more semi-annual California emissions test, then I'd rebuild it at some point. I had been burning premium as a band-aide, to keep it from pinging, from the oil burning issue. After failing the emissions test burning premium, I filled it up with regular gasoline which improved things, but it still failed. Regular burns faster than premium, often more completely resulting in fewer hydrocarbons out the tailpipe. But my NoX was also high, likely from the oil burning. I then installed a CARB certified high-flow PCV valve, and in-line oil mist separator. It passed after that. I reduced that car's duty to 'around town' trips, but had to bring it in for emissions testing in June. Fearing the it would fail, I took some advice from a friend and removed the catalytic converter's heat shields, wrapping the cat with fiberglass thermo wrap header tape, in an attempt to get the cat up to a higher temperature and to retain it during the test, to burn off more of the hydrocarbons. With little margin, it passed the California rolling dynomometer, sniffer, and visual test. That car is getting a rebuilt engine next month. |
![]() |
|
| BillHoo | Oct 1 2013, 11:11 AM Post #48 |
![]()
|
The car runs just fine now and I can accept 48 mpg. Just the the state of Virginia wants it to lose 20 ppm of hydrocarbons. Otherwise, I can't drive it until it turns Age 25 - in three months. Edited by BillHoo, Oct 1 2013, 12:18 PM.
|
![]() |
|
| BillHoo | Oct 1 2013, 11:14 AM Post #49 |
![]()
|
Went and retested this morning. No adjustments on timing. 7 gallons regular gas and two bottles of HEET. Drove the car for about an hour at 60 mph. Got to the testing station and left the car idling for 10 minutes or so before they could get to it. Still fail and HC got worse! Everything else got better. ![]() I made some graphs to compare the First TEST vs. the Re-TEST ![]() ![]() Edited by BillHoo, Oct 1 2013, 12:15 PM.
|
![]() |
|
| Deleted User | Oct 1 2013, 12:00 PM Post #50 |
|
Deleted User
|
|
|
|
| BillHoo | Oct 1 2013, 12:10 PM Post #51 |
![]()
|
Next attempt. - Go back to Premium gas - No idling while waiting - No fuel additives - Retard to factory specs 5 degrees If I have to do it again after that, I'll advance to 15. |
![]() |
|
| ascensions | Oct 1 2013, 03:45 PM Post #52 |
|
Je conduis une petite voiture.
![]()
|
As I've stated previously, run a bottle of Techron Chevron through an entire tank, set your timing to 5, and bring it in warm. I have a feeling it WILL pass. That said, I've never tried it, but there's this too... and people swear by it: http://www.amazon.com/CRC-05063-Guaranteed-Emissions-Formula/dp/B000CIPUR8 |
![]() |
|
| BillHoo | Oct 1 2013, 05:50 PM Post #53 |
![]()
|
Thanks! A lot of this is to satisfy my scientific curiosity. ![]() |
![]() |
|
| Woodie | Oct 2 2013, 05:32 AM Post #54 |
![]()
|
Okay, fourth time now: Premium gas and retarded timing are two ways to GUARANTEE an increase in unburned HC and a decrease in NOx. It's possible that you're burning so much oil that nothing is going to do it, but both of these are going the wrong way. just the Jay the science works. |
![]() |
|
| idmetro | Oct 2 2013, 07:08 AM Post #55 |
![]()
|
As others have mentioned the oil being burned is likely a big player in your numbers. As a reasonably cheap thing to try I suggest pulling the spark plugs, pour some seafoam (1/2 cup or so) in each cylinder and let it sit overnight. In the morning stuff some paper towels in the sparkplug holes, spin the engine over a couple of times, remove the paper towels and clean up any mess, re-install the plugs fire it up and then take it for a spin. She'll likely start hard and smoke a bit (ok perhaps a lot at first), but if you get lucky, allowing the seafoam to sit overnight will have given it time to work on the deposits on the oil control rings and just perhaps clean them up a bit allowing them to seal a bit better thus reducing the amount of oil that is getting by them and perhaps let your engine function well enough to get by the emissions testing. Disclaimer: I have never tried this in relation to an emission test but have had reasonable luck reducing the oil consumption of engines that ran well but consumed more oil than I thought they should. |
![]() |
|
| ascensions | Oct 2 2013, 07:43 AM Post #56 |
|
Je conduis une petite voiture.
![]()
|
If oil burning is a problem, why not go to a thicker oil for inspection? SAE40? |
![]() |
|
| High MX | Oct 2 2013, 07:45 AM Post #57 |
![]()
|
I don't see how oil consumption be the issue since the problem is only at low speed/idle. If oil consumption was an issue it would be evident throught the testing. I believe that sitting there idling for 10 minutes let it load up. When the rpm/speed was increased the gains in his improvements are clearly evident with improved emissions numbers. Our three cylinder engine has a lot of dwell time between ignition events which lends to it loping like a V-8 with a big cam at idle. Ever notice how your engine shakes when the idle is low? The speed at which the crank is turning is changing due to dwell time between compression and ignition cycles which causes the engine to shake. That is why you see race cars rev their engines prior to the green flag or staging so they can clear out any unburnt fuel that collected (i.e. "loading up") while it is idling. If it were me, If I had to wait that long to retest I would shut the car off. Then, right before I pulled it in, I would rev the motor at about 2,000 rpm for a few seconds to blow out any unburnt fuel that collected from it idling. I think your car is capable of passing the test as it is. |
![]() |
|
| truckjohn | Oct 2 2013, 10:28 AM Post #58 |
![]()
|
Any way you can make an adjustment to lean out the mixture a hair at idle... especially when the engine is hot? O2 sensor tricker, ECT tricker, MAP tricker, etc? Notice your NOx is lower - which points towards your engine running a cooler combustion temperature.... The other thing I gotta wonder about is the residual oil in the exhaust system causing you issues at idle.... Your HC is high - but the CO isn't high... which could mean stuff is vaporizing in the exhaust system..... Notice how your HC for idle and 25 mph are nearly identical..... A 1/2 hour drive on the freeway at 55 or 60 isn't going to burn out the oily junk in your tail pipe - likely, it will make it WORSE.. .as it gets that sludge good and hot so it starts gassing off.... This sort of thing would lead me to try getting the car out on the highway at 85 mph for about 2 tanks of gas.... Burn out all that trash..... Even better... Give the keys to your 16 year old son and tell him to go drive it on the highway for you.... Emphasize how you puttering along won't do anything.. you need it RUN good.... Thanks Edited by truckjohn, Oct 2 2013, 10:35 AM.
|
![]() |
|
| High MX | Oct 8 2013, 06:53 AM Post #59 |
![]()
|
Did you pass yet? |
![]() |
|
| BillHoo | Oct 9 2013, 02:22 PM Post #60 |
![]()
|
Doh! I just got back from Test #3 50/50 mix premium and regular gas with two bottles of HEET. Set the timing to 8 degrees Drove it for an hour to get hot and drove into test station with one car ahead. 10-15 minutes later it was tested and failed. Again, just the HC, this time high numbers on both 15 mph and 25 mph idle. Went home and popped the hood to put the timing up again and found DOH! I had forgotten to put the vaccuum hoses back on the distributor! Think those would affect emissions? |
![]() |
|
| 1 user reading this topic (1 Guest and 0 Anonymous) | |
| Go to Next Page | |
| « Previous Topic · Intake and Exhaust Systems · Next Topic » |


Welcome to the all new Geo Metro Forum. We hope you enjoy your visit.











7:57 PM Jul 10