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failed emissions in Houston, TX

T

TheEmissary

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Houston, Texas
I took my 81 Blazer 4 x 4 to the local smog station, and here's what I ended up with:

Low Speed Emissions 15 mph

HC 540 (standard 286)
CO 2.07 (standard 1.64)
NOx 1264 (standard 2125)

High Speed Emissions 25 mph

HC 501 (standard 281)
CO 2.21 (standard 2.26)
NOX 1179 (standard 1980)

I am running a bone-stock Quadrajet with 4.5 turns, modified HEI distributor with an MSD module and coil, Bosch Platinum +4 plugs, and a Speed-Pro CS1013 camshaft, with Keith Black 120 pistons.

I gassed the vehicle with Chevron 93 - the motor ran smoother, and right after the test failure, I went ot Midas to have the catalytic converter replaced after consulting with 2 smog inspectors after having another vehicle which passed.

Just this evening, I have noticed that my CC was plugged because I had swapped the original 305 with a 350 in December 2001 - the 305 was an oil burner. There was evidence of a damaged catalyst brick, and from what I have done since this past Thursday, I have examined my old set of plugs, and all of them were tan/yellow in color - indicating a properly tuned motor.

I have set the static timing to 8* BTDC, and currently running a 160* thermostat. I have 2 choices - either to park the vehicle for 2 years until April 2006, or drive it with an expired inspection sticker.
 
[ QUOTE ]
HC 540 (standard 286)
CO 2.07 (standard 1.64)
NOx 1264 (standard 2125)

High Speed Emissions 25 mph

HC 501 (standard 281)
CO 2.21 (standard 2.26)
NOX 1179 (standard 1980)



[/ QUOTE ]

I have to get my 1970 tested annually but since it doesnt have any smog equipment they just dyno it.

Here's my results in Feb with a 350 (flat tops, Q Jet) no smog pump, no cat, no vac canister...nothing except a PCV valve.


HC idle 177
CO idle 2.37
HC loaded 129
CO loaded .09

Maybe your plugged cat was causing the high readings, even without a cat you should be in this general range.

/forums/images/graemlins/dunno.gif
 
You mentioned the aftermarket camshaft, but what are the grind specs? Anything too aggressive, and it will definately fail emissions, really can't go much more than the "R.V." cam.
 
I had an rv cam in a previous vehicle, i had to run the timing alittle more advanced than stock, i believe around 10-12 degrees and had to have a vacuum leak to lean out the air fuel mixture quite abit. I had a cat inline, but found out it was hollowed out, wasn't working, but there. My HC's were always high, which i was told was highly due to the cat in it's condition and the cam grind.

Just needs tinkering with, you SHOULD be able to get it adjusted right.
 
Here's the cam grind from the cam card which I have archived:

valve lift: .420/.443
cam lift: .280/.295
.050 dur: 204/214
SAE dur: 278/288
C/L: 107/117
 
what part of houston you from? i had a little trouble gettin my '91 passed in harris county...... it depends on where you go..... the guy that passed mine didn't feel like putting it on the dyno since it's 4wd... he said... "we'll just assume it's full time all wheel drive" mine has all the air injection crap removed, no pre-heater hose, headers, changed cat configuration (true duals), and has dumps (which is illegal on SUV's). but, my motor is new and mostly stock, and has 2 new cats. he doesn't know what to look for in terms of emission equipment..... he just sticks the sniffer in the tailpipe, and let's the machine say if it's legal or not.

did you try that stuff in a bottle that says it's guarenteed to pass you?? it definately helps to add that to a full tank of gas..... and, it helps to bring it in when the motor is nice and hot.
 
Chris:

I am located in Southwest Houston off Beltway 8 and Hillcroft in Fort Bend County. I can detail a lot more via my current e-mail address.

I could have taken my M.P. into Colorado County for a bootleg sticker this morning; or have the registration renewed without the inspection sticker instead.
 
You should try setting the ignition timing with a vacuum gauge and not a timing light. With an aftermarket camshaft, a timing light means nothing anymore because aftermarket camshafts, when machined, are not indexed to the crankshaft like GM OEM camshafts are. If you where to bring the number 1 cylinder, on your engine, to top dead center compression stroke, and used a degree wheel to find your camshafts true index to the crankshaft. I bet you would find the camshaft to be as much as 4 to 12 degrees off of true top dead center.

First, when you use a vacuum gauge, make sure it is connected to manifold vacuum. Second, advance the distributor until it reaches maximum vacuum (with an aftermarket camshaft this might be as high as 8 inches of vacuum or as little as 6 inches of vacuum). Third, back it off a half-inch of vacuum. Since you are trying to pass smog inspection you could try backing it off from 1 to 1 1/2 inches of vacuum, but after you pass smog readjust it to only 1/2 inch off of maximum vacuum for performance.
 
oh so your not in harris county? sucks they are implementing the exhaust nazi rules in the surrounding counties b/c people commute. they even have those white vans sitting on the side of freeway onramps sniffing tailpipes, and sending tickets in the mail. in harris county, they dont even care about the sticker.... they want to see the printed documentation that says it passes the harris county emission restrictions.

im up on the north end btw. by humble.

my advise would be to make sure your cat(s) are operating properely, run some of that "G2P" stuff in a full tank of gas. burn that through. refill. go cruze at 70 on the highway for a half hour, then immediately take it in, and try again while it's still hot. they should allow you to test again like 2 or 3 times without having to pay again.

one other thing..... i know there is a loophole that says if you spend more than X number of dollars in between your first failed test, and your 2nd or 3rd failed test, trying to make it pass, it automatically passes if you can prove you spent the money for emissions equipment. i believe it's only like $200 or $300.
 
As of this writing - I have a repair bill for the catalytic converter; I am in the process of switcing the thermostat to a 195 in place of a 160, along with a carb rebuild.

The following link has a current pic:

http://houston.indymedia.org/news/2004/04/28142.php

Since the vehicle is currently used as an art car, there are a few which have been on the streets without an inspection sticker.
 
Try ditching the Bosch Platinum plugs for some good 'ol AC Delco's. Those tiny tips on the Bosch plugs didn't last long in my 4.3L S-Jimmy and caused it to fail the sniffer here in Colorado. Swapped the plugs to AC Delco's and it passed WAY under the limits. /forums/images/graemlins/eek.gif

BTW, I'm a former Fort Bend County resident. /forums/images/graemlins/thumb.gif I used to live in Missouri City, just off Hiway 6. /forums/images/graemlins/cool.gif
 
I was just gonna mention swapping in a 195* thermostat.

Good luck. I am suffering my own emission woes. It's only a visual but all the emissions stuff was removed from this 86 when I got it and I've already dropped $500 on parts /forums/images/graemlins/yikes.gif
 
[ QUOTE ]
I am suffering my own emission woes. It's only a visual but all the emissions stuff was removed from this 86 when I got it and I've already dropped $500 on parts

[/ QUOTE ]
I hope that all those guys that are ripping off air pumps, EGR valves, etc. are listening... Just because the gov't doesn't test for emissions in your area today, it doesn't mean that they won't in the future! /forums/images/graemlins/yikes.gif And yes, they almost always make the law retroactive and they don't care why the stuff is missing, they just make you replace it all anyway. /forums/images/graemlins/eek.gif
 
When mine failed in Collin Co, I was given a list of Certified Emissions Repair places....I was told that if I kept receipts for $200 in repairs, I could get a tag...

As it turned out, my new Bosch O2 was crap from the box, and I needed a 195* thermostat....I would suggest paying the Certified place the $75 diagnostic, and replacing what They reccommend rather than guessing at stuff and throwing money in all directions...

I run Headers, true duals and dual cats on my 89....137K and smokes on startup due to bad seals....I pass on reg gas and no additives.....Best of Luck to Ya... /forums/images/graemlins/waytogo.gif
 
I have done a carb rebuild this evening, right after the second and third re-test, since my HC and CO levels stayed constant.

Here's the details of the Q-jet which I have stripped - whcih was a remanufactured unit from Holley:

primary jets: 72
primary rods: 51M
secondary hanger: H
secondary rods: DR

Here's the shocker: the APT adjustment was off since I have installed the carb back in 1999. I turned the APT screw all the way in, and backed it out 2 turns. After the rebuild, I took the M.P. on the highway, and the acceleration was more quicker than usual.

Why the APT adjustment - the mechanic who did a flush of the intake, intake valves et.al. was a vet who worked on Quadrajets since the early 1980s. He recommended to turn the APT screw all the way in, and back it out 2 turns. The mechanic was correct of what he stated.

The end result was a crisper acceleration rate; if this results in lowered HC and CO ratings, it's a 50-50 chance.
 
I dunno about there, but here the $200 exemption only applies if you are REPLACING parts you already have. If your vehicle doesn't have a cat on it the cost to purchase one doesn't count. Also don't think that when emissions comes to your area you'll easily be able to hit the salvage yard for the parts you need. Emissions inspection went into effect in my county in feb and 2 months later every boneyard for 100 miles in any direction was picked clean. From 8 yards I found 2 air pumps and valves for cores (one was for a friend).
 
I have opened the 73-87.com archive - the mechanic who recommended the APT adjustment with 2 turns out when I had my vehicle topped off with fuel injector cleaner was correct about the 2 turns.

http://www.73-87.com/7387garage/drivetrain/myqjet.htm

The rebuilt carb that I have on my 350 was not adjusted properly when it came out of the box. My recommendation for those who have been rebuilding Quadrajets manufactured after 1975 (75 - 86 vintage) - re-adjust the APT screw with 2 turns, and keep a note about the jets and rods which comes with remanufactured Quadrajets (and Dualjets bult before 1981) when rebuilding the carb.

I was about to bid on a brand-new Edelbrock Quadrajet; this should solve the high HC and CO levels.
 
you did all the things that I would suggest you not do, 1 change the oil 2bump the timing, till it pings under load 3make sure pvc valve is functioning,4 readjust the air/fuel mixture screws to 2 1/2 turns out,5 change your air filter,6
make sure the cats are working, 7 if all that doesn't do it then you think about re-jetting /forums/images/graemlins/waytogo.gif /forums/images/graemlins/waytogo.gif /forums/images/graemlins/hack.gif /forums/images/graemlins/weld.gif /forums/images/graemlins/grind.gif
 
Re: higher NOx

I have returned home form the testing faciliyt this afternoon, and noticed that my NOx levels have risen, right after the carb was rebuilt. Here's the test results:

HC: 281 (111 25 mph)
CO: 2.26 (0.02 25 mph)
NOx: 1980 (2318 25 mph)
 
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