If you've read up on my other post in the Exhaust section you'll have a good point of reference. If not, here you go:

https://www.thirdgen.org/forums/exha...ction-2-a.html

This post is in regards to emissions. In any case, I'll be needing additional help. I eluded to the fact that there was more to the story, so here it is:

The car in question is a 1985 Pontiac Trans Am, VIN H, T-5 manual. My dad bought this back in the 80's, and we've been swapping the vehicle back and forth ever since. We've driven it across the country in multiple directions many times, but the most fun we've had in it was in the middle of the desert when I was stationed at TwentyNine Palms, CA. Everytime I'd get it back from my dad, there were new upgrades--mostly suspension. The car has seen a lot of road--it'll be turning over the odometer for the 4th time soon if I can ever get it registered here. Since the time that the warranty came out it never had emissions equipment, save for the cat. It being registered in FL, this was never a problem.

When I came back from Iraq in 2005 I bought my dad a crate engine as a gift. We wrenched on it together and continued to drive the cr@p out of it until he passed this year. Now that he's gone, the car is mine again. But I live in Colorado now, which has rather strict Kalivornia-like emissions laws. In order to get it registered it will need to pass emissions. This was not an easy task, as I had to procure the AIR system, an EGR manifold, a Quadrajet that the car originally came with, and many other miscellaneous parts. What's worse is that it has headers (more on that later). In any case, it needed to look stock just to pass the visual inspection. Battle won, war ongoing.

So, here's what's in it:
SBC 350 4 bolt main
73cc heads with 1.94 intake/1.5 exhaust valves
1.5:1 rocker arms
8.5:1 compression
Camshaft is hydraulic flat tappet with .450/.460 lift, duration at .050 is 222 Intake/222 exhaust, lobe centerline is 114* ATDC Intake, 114* BTDC exhaust
Standard set of Hooker headers.
10" of vacuum at idle (~700 RPM)

This is what I have to work with unless I throw another JY engine in it, which I 'really' don't want to have to do.

The AIR system was the most difficult. In order to be emissions compliant it needed all those little air tubes in the exhaust headers that get in the way any time you want to check/replace your spark plugs. I welded bungs to the tops of the headers and modified some stock air tubes I came across at the JY on order to fit. PITA! I replaced my nice Edelbrock intake manifold with a stock cast-iron manifold with EGR provision, and replaced a nice modern Holley carburetor with a QuadraJet I sourced at the JY as well. Of course, there was all the emissions tubing, air piping and the like to add, as well. Got all of this done only to find out that the emissions station wants to see 2 catalytic converters, regardless of what the book says. So I added an additional one as well. I've finally passed the visual. This is important because if anyone were to look too closely they'd notice that there are parts of the emission system that are non functional: namely the EGR. The reason I made this non-functional is because of the lobe separation on the camshaft. This lobe separation creates a natural EGR effect, and adding additional EGR as commanded made the car run extremely lean at lean-cruise, and made the car buck going down the road. Adding fuel made things worse in other driving conditions.

I had to re-jet the Quadrajet. Did it several times, and the most satisfactory combination so far has been with "70" jets and 41K rods, and the secondary air plate spring torqued down quite a bit. Using a wideband, but it's useless and the AEM tech says I need to send it back for RMA. Until I get a working one, all adjustments will continue to be 'seat of the pants'.

I was able to pass the visual inspection today. Happy about that, but I'm not passing the sniff test on the dyno, and the car is getting HORRIBLE gas mileage. I could get 19mpg before, I'd be surprised if I get 10 with all this junk all over the engine.

Here are my current liabilities that I still need to mask, if I can:
--Increased displacement.
--Slightly "lopey" cam that likes a rich mixture at idle to run smooth.
--Timing control: The stock engine timing was controlled by the computer. The computer does not appear to be able to adapt to the new engine, so as of now, the timing is controlled by springs only. I removed the vacuum can so it would look more stock in order to pass the visual.
--A tech that likes to run the dyno test at 50 Mph in 2nd gear: Here are the test results

HC GPM: 5.4190, Limit is 2.5 FAIL
CO GPM: 111.2625, Limit is 20.0 FAIL
CO2: 502.9758, no limit specified
NOx GPM: 0.1374, Limit is 4.5 PASS
Check Engine Light: PASS (I'll tell you how I did this after I pass the rest of the test, if I can)
Catalytic Converter: PASS
AIR Injection System: PASS
O2 sensor presence: PASS
DTC: PASS

The very strange thing is that the car fails the initial test within the margin to qualify for a "second chance" test, yet with the second test, it fails miserably.

So, here's where I need to be steered in the right direction. Let me know if you see issues with my strategy.

--First, I need to get a working Wideband. The AEM sucks, and I'm sure my calibrations on the carb and timing are incorrect due to a faulty setup. Don't buy AEM, folks.

--Second, I need to get the timing under control. I believe that the timing cannot be advanced enough during lean cruse due to the absence of a vacuum canister. I'll need to add it and hope the inspectors don't catch it (this car did not come with one). Also, as I only ever get about 10" of vacuum at idle, I'll need and adjustable one. I'll have to buy one and find a way to make it look like it's been on there for years, or maybe find and adjustable one at the JY. This 'should' improve things, and should also drive up my gas mileage.

Since the NOx levels are so low already I should have plenty of room to advance the base timing without adversely affecting it. It's set at 12* BTDC currently. The springs advance it to about 31* at 2800 RPM.

So, this is where I stand, but I believe that there is something that I'm missing, or something that I can do in addition to help these numbers come down.

What are your thoughts?

Edit:
It just occurred to me why the CO readings are high. The Catalytic converter will break up the NOx molecules, which in turn frees up an Oxygen molecule. This Oxygen molecule will combine with the CO inside the cat, forming CO2. Since my NOx readings are so low, I don't think that there is enough oxygen being freed up in order to combine with the CO. I need to think about this....

 

Funny how they measure CO2 when it's NOT a pollutant. In fact plants and trees love it...

 

I'm all for clean air (as I'm sure most of us are). But I don't need some kind of scam to get me motivated. The desire to live in a clean place is enough for me so I really hate all the hype that is put on about global warming, greenhouse gas, and the like because they never seem to have a common sense approach for solving the problem. And even when they DO come up with a solution, if it's not the 'politically correct' solution, it does not see the light of day. Furthermore, in the fight to clean up the planet, we're a leader, and when you want to get a group of people moving in one direction, you pick up the stragglers, not the ones who are in front.

Case in point: I just had to remove equipment that made my engine run efficiently and well (to pass a visual inspection) and had to re-mount old equipment that is outdated and less efficient. Now I have an large emissions problem where a large emissions problem didn't exist before. But alas, I didn't add this comment to be a spokesman for the EPA, or against it. And I certainly don't want this thread to turn into an enviro-debate thread. Just want some guidance on how to get these numbers down with what I've got.

 

Grab yourself a jug of Methyl Hydrate from Home Depot, and mix it in with your gas, and you should pass the sniffer test. Take a look at this thread to see how fellow TGO members have used this (as well as other clean burning fuels) to get past the sniffer tests. https://www.thirdgen.org/forums/thir...e-mix-gas.html

 

It may come to that. There's enough alcohol in the fuel already here, don't want to put more in. Pump say's there could be as much as 10%, but I'd bet it's at or above 10%.

Here at altitude (I live at about 6700 feet) I have a problem keeping the fuel from boiling. The lack of air pressure, and the fact that my fuel lines pass next to the exhaust header collector on the passenger side, make it hard to keep fuel pressure where it's supposed to be.

When I get home I'm sending AEM the info required for RMA of the Wideband gauge/sensor. So pissed that I spent over 200 bucks on that thing, only not to be able to rely on the data. AFR gauge shows lean, but the sniff test shows everything in the "very rich" range. F'kng POS.

 

May need to beef up the heat shield where the fuel line passes the header, to keep the heat off the lines there. There is enough alcohol in fuel already, but this does work, as I've personally done with my GTA, before my LS swap. You'd dilute a small amount of fuel (1/8 of a tank) with the methyl hydrate right before you drive to the test, then try to run the car almost dry on the drive home, and fill er up with some ethanol free if you can find it, or Premium, and drive the car around a bit more to get the rest of the methyl hydrate out. As long as it's not in there a prolonged period of time, it shouldn't hurt anything.

Innovative Motorsports make a good wideband kit to look into if you're not happy with the AEM unit.

Good luck getting the car on the road, it'll be worth the trouble once you get past their emissions BS.

 

Is it as simple as the engine just getting an incomplete burn? That's anemic compression ratio. Maybe spark plugs are too cold. Spark timing is very important.

 

It's actually a whole slew of things. 1, the timing isn't controlled by anything other than the springs. I need a vacuum advance so I can lean the mixture out at lean cruise. 2, I think I still need to either go down in primary jet size, or up in metering rod size. I have a couple of 68 jets that might do the trick with my 41K rods. If not, I have a set of fatter rods. 3, I REALLY need to look at my fuel supply problem. My headers run too close to the fuel line on the passenger side, so readings are inconsistent when the fuel starts to boil. I get everything adjusted, but as soon as the car cools down everything is out of whack again.

I've got a little bit of work ahead of me, but I'm holing off until I get a FUNCTIONAL wideband.

 

I have my fuel line near the header wrapped in a Velcro heat wrap by DEI. It also wraps the clutch hydraulic line. It's loose, dries out easy, and very simple to replace if needed.

 

Update:

AEM sent me another wideband gauge. It was also dead on arrival. I took some video of it and they sent me yet another gauge and sensor. Installed it yesterday and this one appears to work correctly (for now).

With the help of a WORKING wideband I've now re-rejetted the carb with #70 primary jets and 50V primary metering rods. The 41K primary metering rods are just to thin for the altitude. I now have better mixture control over the idle and the carb runs a tad bit lean at higher RPM--about 15.2:1. The following is only speculation at this point, but that should drive up the NOx emissions a little bit, but as I have plenty of room to play with there, I 'should' be good. Also, it 'should' allow the cats to do their job and create a spare O2 atom from the extra NOx, which will combine with the CO, lowering my CO emissions. Since it won't be running as rich, my HC emissions should drop as well.

I'll find out next week when I take it back for another test. Let's hope the tech doesn't test in 2nd gear again this time.