Carbed in MA: Failed Emm(HC:2/1.2 CO:27.37/20) Need tips!

[crazypete]

Hi all. I'm trying to get this beastie past emissions in massachussetts. She passed everything else with flying colors. They didnt say anything about the grease either . They even looked past my fake pcv and charcoal cannister.

I attached the emissions sheet. It failed for hc 2.00/1.20 and CO 27.37/20

Nox was 2.12/2.50
CO2 was 489.42 (no limit).

Now I know I trying to pass a carbed motor on an EFI platform so I'm in for a pickle of a project. I got hold of 4 catco 2 1/2 catalysts. These things are so huge that the 2 cats back to back go almost from the longtubes to the catbacks so I only used a single pair for the moment on a cut up BBK midpipe. So

-the cats are fresh
-I am running the smogpump to the back of the heads
-no EGR (the spacer prevents this from being hooked up)
-no vacuum advance on the dizzy. I am running 24 degrees initial (I think my balancer has slipped since the car didnt run at all at 10 degrees and 24 seems a bit high). But nox was decent so I'm no worried about timing.

Holley street avenger 570 is set up pretty damn lean already 56/58 jets, 5.0 powervalve, idle set 1/4 turn above stumbling, .28 shooter with factory white pump cam, clear long secondary spring. I am running 6 oz of acetone on an 11 gallon fillup of 87 octane.

I did notice though that the car on the dyno is tipped forward.......this would affect the float levels, wouldnt it?.......lean it out since the gas is tipped away from the metering block

So what now? I heard about folks using denatured alcohol but I am already running acetone. Should I somehow wedge my second set of cats in there? The only way they will fit is if I cut the heatshields off the front pair and tuck them into the humps of the crossmember but Im worried about melting the poly bushings.

What do you all think?

Thanks for looking!

 

[jrichker]

Ford at their best couldn't make carb'd cars pass emissions consistently. That's why they went EFI. What makes you think that it can be done?

High HC - carbs cannot lean the cruse out enough to run the 14.7:1 air/fuel ratio and get the car to run without sputtering and backfiring under low load acceleration.

No EGR makes it very difficult to drop combustion temps down enough to reduce the NOX emissions. A working EGR also reduces cruse level HC

In order for the cats to work properly, the air has to be directed though them at the right time. Putting air in the heads was designed to be only for 30 seconds or soon a cold startup.

The computer that you dislike controlled all of this in a manner that made it invisible from the driver’s seat. No computer, then there is no way to orchestrate this complex symphony of moving parts.

Adding alcohol will only reduce the CO emissions: it won’t do anything for the HC & NOX emissions.

Politely, your enthusiasm for carbs has exceeded your ability to make them function in a real world environment. In the vulgar vernacular of the street, you have screwed yourself.

Here's a book that will get you started with how the Ford electronic engine control or "computer" works.

Ford Fuel Injection & Electronic Engine Control 1988-1993 by Charles Probst :ISBN 0-8376-0301-3.

It's about $20 from Borders.com see http://www.amazon.com/ . Select boo...very good, and I found it to be very helpful.

 

[crazypete]

Ford at their best couldn't make carb'd cars pass emissions consistently. That's why they went EFI. What makes you think that it can be done?

Quite simply.....because I need to.

This is the car that I have and I need to get it through the inspection so I can drive it.

The numbers are not THAT far off to make this situation hopeless. I have a perfectly sized carb for the engine, a very powerful ingition system, a street torque cam, catalytic converters, smog pump.

I still have a second set of cats I can install inline to burn off some of this HC.

High HC - carbs cannot lean the cruse out enough to run the 14.7:1 air/fuel ratio and get the car to run without sputtering and backfiring under low load acceleration.

I am seeing a little of this sputtering now. I fixed it by advancing the timing. I guess I can lean it out some more and give it even more timing.

No EGR makes it very difficult to drop combustion temps down enough to reduce the NOX emissions. A working EGR also reduces cruse level HC

I have no way of controlling the egr valve. The vacuum from the manifold will just peg it open nonstop. I tried just running an open egr valve (egr constantly running) but the car simply wouldnt run at all. I dont think I will be able to do an EGR setup.

In order for the cats to work properly, the air has to be directed though them at the right time. Putting air in the heads was designed to be only for 30 seconds or soon a cold startup.

Doesnt injecting at the exhaust ports eventually end up in the cats as well? I thought it was a more upstream injection. It seems like a good idea since the HC burning will commence all the way up in the hot exhaust ports before it even reaches the coverter. I have never seen any kind of backfire from doing this.

The computer that you dislike controlled all of this in a manner that made it invisible from the driver’s seat. No computer, then there is no way to orchestrate this complex symphony of moving parts.

It was a nice little college project to do something with a car that had suffered catastrophic electronics failures (dead eec, toasted maf, hot grounds, the works). Staying with my EFI was simply not an option I could afford.

Even now, I just moved into an apartment so doing an efi swap is likewise out of the question. The only thing I could do would be a holley commander tbi setup....in a few months when I can afford it.

More realistically though...I need to get this setup here working. Lamenting my choice of fuel induction wont get me any closer. It's not, after all, that far off.

 

[jrichker]

I still have a second set of cats I can install inline to burn off some of this HC. .

Cat coverters are sensitive to temperature - move them too far away from the heat and they lose efficency. Get them too hot and they melt.

I am seeing a little of this sputtering now. I fixed it by advancing the timing. I guess I can lean it out some more and give it even more timing.

Leaning out the mixture and advancing the timing increases NOX.

Doesn’t injecting at the exhaust ports eventually end up in the cats as well? I thought it was a more upstream injection. It seems like a good idea since the HC burning will commence all the way up in the hot exhaust ports before it even reaches the converter. I have never seen any kind of backfire from doing this.

The air injection works with the catalyst to convert the HC to H2O and CO2: it isn’t just burning up the excess HC.

The whole process of emission control needs to be understood before you can attack any of the specific problems. That’s why the reference to the Probst book was included in my post.

 

[vristang]

Crazypete- you are legendary, but I have to agree with Jrichker. This is not the way to pass emissions.
They should be failing you just for having a carb.

Yes you are close, but you are close on all emissions. You can't sacrifice NOx to improve HC.

Coolant temps can have an affect on HC emissions.
Since you are on rollers, what is your tire pressure?

Adding the second pair of cats probably won't make any difference as they will not get enough heat to operate properly.

That is about all I have, other than recommending swapping back to efi.

jason

 

[crazypete]

Crazypete- you are legendary, but I have to agree with Jrichker. This is not the way to pass emissions.
They should be failing you just for having a carb.

A carb is not the end of the world......mustangs came with them through 85. I think the reason they dont grill me on it is because I'm running the 85 4-eye facia and mouldings and they dont make the connection between the 1991 on the registration and the fact that I should have efi (a well thought out ploy!)

Yes you are close, but you are close on all emissions. You can't sacrifice NOx to improve HC.

Just how bad is 2.0/1.2 anyway? Thats a sliver of a difference right?

Coolant temps can have an affect on HC emissions.
Since you are on rollers, what is your tire pressure?

Tire pressure is high 20's/low 30's

I didnt know tire pressures made a difference....I'll go pump them things up to 40.

The temperature idiot guage shows just below half and I am running a fairly new 195 degree thermostat. There are no known overheating issues with the car.

Adding the second pair of cats probably won't make any difference as they will not get enough heat to operate properly.

Can they hurt anything? (other than performance, which is secondary right now)

I figure if 1 set gets me to the fairly decent numbers above, the second set will get me the rest of the way (crosses fingers).

That is about all I have, other than recommending swapping back to efi.

jason

Like I said before, an EFI swap is not even remotely feasible with my financial situation (I'm not peniless but I cant afford to throw $1500 at this right now) and quite honestly...it would feel more like "giving up" than anything.

Heck...someone else must have done a carb swap on a registered street car other than me. This thing runs so well, I mean so well. It doesnt even smell bad, it's quiet, idles smooth and solid, starts right up, a real tame creature.

I was kinda looking for neat tricks like pouring alcohol in the tank,etc....

For the moment, I'll try every half assed trick to get her past emissions:
1. second set of cats. Meow!
2. alcohol in the tank 1-4 ratio
3. Lean the hell out of the carb
4. Inject air to the cats direct and pull exhaust out of the thermactor ports and dump it to the fender or someplace.

Then if this fails, I will throw my hands in the air and go looking for an EFI swap.

 

[Dark Knight]

They make cats that dont need an air pump feed, get some of those. Do you have to just pass idle and cruise, or the full roller test? Might try running a heavy secondary spring and run some denatured alky..

 

[vristang]

Lower tire pressures can increase drag. This will make a minimal difference if any.

Higher coolant temps will allow higher combustion temps which will reduce unburned HCs. However, higher combustion temps will also increase NOx. This is where you will have a hard time making tradeoffs.

It won't hurt to install the second set of cats, but it will shorten their life and make only a small difference.

I would like to hear what changes you make and what your results are on the next test.
We don't get enough before and after emissions test data here.

jason

 

[snoboardcore]

when i lived in az i had to do emissions on my car and i failed miserably 37 and it was only allowed 12. I went to home depot bought 3 gallons of denatured alcohol and stuff that in the tank with two gallons of gas and it brought my HC level down to 11.99. So try some denatured alcohol in there and see what happens. Mind you that car had absolutly no cats in it what so ever.

 

[jrichker]

Just how bad is 2.0/1.2 anyway? Thats a sliver of a difference right?

Close only counts in horseshoes and hand grenades...


Like I said before, understand what makes the engine pollute and then you can take the correct steps to fix it. That's a much better plan than shooting in the dark and hoping you do the right thing.

 

[crazypete]

Holy conflagration batman!! (sorry long post...epic story)

Short version: leaned out the carb, car ran like crap and smoked, restored original settings, car still smoked, exhaust stream at taipipes so hot it burned my hand, all the paint on exhaust pipes behind the cat outlet caught fire. Cats still have paint, engine was normal temp.

I almost lost the car last night to a massive blaze! If the car had not been down in the backyard (near a hose) this would have been curtains for the stang. I also found out that every fire extinguisher in my house is dead.

So here's what happened.

I installed the cats sunday and drove around for 3 days on them now. A little bit of smoking (an occasional wisp really) but nothing that could not be atributed to some burning paint or a little burning grease. Timing was set to 24 according to the balancer.

So I get home last night to see if I can lean it out a bit. Turns out the jets were 54's not 56's. Ok, I say, lets drop to 50's and see if it runs at all. Well, it "ran" but real poorly. I figured it would run a bit different if it warmed up a bit so I took it around the block. Horrible smell of rotten eggs, no power. By the time I got back, the underside of the car was smoking furiously. No problem I think....got a little hot under there and burnt some grease. Too lean. Lets try 52's. I mean....54 to a 52 shouldnt be more than a 6% difference in fuel flow from its perfectly running self. Same thing to a lesser degree. Ran like ass, smoked furiously after going around the block. The mufflers were making that ting ting ting hot metal sound. There was black smoke puffing from the exhaust as it ran. (black smoke?? I thought it was lean??)

WTF. I put the 54's back in, wait 10 minutes and it didnt want to start at all. WTFx2!! I go up front and loosen the dizzy and have an assistant crank it while I pull the timing back to 10. Still no start. Checked and cap/rotor look fine, pulled a plug, nothing exciting, checkeed a few wires with the timing light and they were all sparking. I finally set the timing to 16 and crank it while holding the throttle at WOT....it reeaaaaally torturously starts and barely idles with the choke pulled out. I reset the mixture till it's 1/2 turn above stumbling and open the idle a little, close choke. Thick smoke begins again.

I go back to feel the exhaust and I had to jerk my hand away cause the exhaust stream is so effin hot. I throw the gate open and aim to take it down to the backyard, reach the bottom, turn around and hop out to put the ramps in.

As I turn around, I see an orange glow under the car, I duck down to look and there's FIRE under the car!!!! Oh ****!!! I kill the engine and run inside and grab both my fire extinguishers. By the time I get out, there is now fire plainly visible.

extinguisher 1......pull pin....fire!!!!!........nothing. Dead
extinguisher 2....pull lever, fire!!!!!...nothing.....Dead.

There is now fire licking up over the bottom of the car. I noticed a garden hose nearby, open the valve and blast. If that hadnt been right there....no more stang.

Luckily.....no interior/structural/mechanical damage at all other than the worst burnt smell imaginable and the shifter selector is a little cloudy (smoke entered through the shifter gap)

I went to go look later that night after restarting and getting her up on the ramps and letting everything cool off.

_AMAZINGLY_

1. Nothing was damaged. Even the rubber hose in the vicinity survived. The fire was paint on the exhaust as far as I can tell and some grease right around it.
2. The cats still have paint on them. The fire and the burnt off paint begins at the exits from the converters to the muffler inlets.

So what just happened???? Why were the muffler inlets on fire but the cats cool enough to keep the paint?? The engine was not overheated and even the headers were @ normal temp. Why was it black smoking from the exhaust when it was obviously lean?

ARG!

Dammit. This car ran like a top 3 days ago then massachussetts had to come along and make me jump through hoops and I almost just lost my car in a fire. Now I'm not even sure what I'm doing wrong anymore.

 

[Dark Knight]

You've got it running WAY to lean... running lean will cause it to smoke too. Is that 24* initial or total timing? And how can you check the timing just cranking it? I'd spend the $$ on a new balancer, if the timing ring slipped it's only a matter of time before it comes apart..

 

[Zero_chance]

Im in MA too and I fail emissions. Why dont you just take the black R and ride with it. No cops ever notice the black Rs, only the red for safety.

 

[crazypete]

Im in MA too and I fail emissions. Why dont you just take the black R and ride with it. No cops ever notice the black Rs, only the red for safety.

The black R !

Mustang TYPE R!



I've thought about it. Get the windshield nice and dirty....not too hard, just need to park on pleasant street for a day or 2 and let these damn trees drop a couple tons of pollen on the car.

That or hit my laser printer and "generate" a sticker...

Doesnt it end up at the RMV though and they reject your plates after a while?

 

[crazypete]

So I took the cats off and inspected them. They look ok. Nothing blackened, nothing melted, the lattice looks fine from front and back.

I put the prochamber back on and it still runs like complete crap.......feels like it's running on 6 cylinders at best and takes a full minute of cranking to start it with starting fluid.

It just occured to me...well 2 things:
1. The exhaust didnt smoke the first day because the welds behind the cats had sheared apart partially so I was leaking a lot of exhaust gas right behind the cats.....I bet a lot of this heat was escaping rather than cooking pipes.I rewelded monday the day before the test.

2. When I changed from 54 jets to 50's....I also changed the power valve from a 5.0 to a 3.5 and maybe this is whats leaking. All that extra raw gas I bet could cook a pair of cats pretty well.

I'm gonna inspect and swap the power valve back tonight as well as build a positive stop and check the timing the old fasion way.

 

[Zero_chance]

Im almost positive they dont do anything with your plates cuz of the black R. Ive had one since two years ago (so either way the stickers definitely invalid just by time alone. Im still wearing the green sticker and I think theyre red now) Anyway, got pulled over not too long ago and my plates were fine. Didnt say anything about the sticker either. My friend that was driving almost told em it was expired too, dumba$$.

 

[crazypete]

The verdict. I was right. Ripped power valve gasket.

I knew something was amiss when I pulled the primary bowl screw and nothing came out. Further evidence was the pitch black plugs and almost oily goo on the threads of every plug. Man...I'm gonna have to seafoam this engine now before my retest.

I tried downjetting and I get the go-bog-go behaviour with some backfiring so the 52's are too lean. I think the 54's are too lean as well and I had ben using the idle screws to cover it up a bit. Downjetting is a no-go.

Looks like it's either alky or double cats.

 

[crazypete]

Ok 2 things:

1. My car is possessed. So I set the timing to 10 degrees and put the jetting to 54/56 3.5 PV, black sec spring. I get this white puffy smoke from the tailpipes....ok I have just seafoamed the engine to get rid of the thick black soot on everything. It was either that burning off or lean white smoke.

I decide after a little driving to set the timing back to the 24 it likes. WOW. White smoke....gone. Hesitation...gone. Backfires.....gone. So I set it to 30 initial. Even better. I'd set it to 40 but my balancer only has marks out to 32. I checked TDC earlier this week and it is accurate. Can an aftermarket cam change timing requirements??

2. Added 2 gallons of alky to 2.6 gallonsd of gas to make a good high mix of alky. Failed my retest. Check this out

HC a whooping 22.24/1.20 (I dont think the alky works, guys)

CO 4.52/20 ( 1/7 of previous reading )
NOX .89/2.50 ( almost 1/3 of previous reading )
O2 449 (no real change)

You could choke in there from the fumes!! This didnt happen before the alky! Whats the octane of alcohol?!? I dont think it's burning at all. I have to drive with the choke pulled all the way just to get the car running normal. That HC reading cannot be right but my nose says it is. It was running like a champ, barely a whiff from the tailpipes and then I added alky and it went to hell.

 

[jrichker]

Alcohol uses a very different air/fuel ratio from gasoline. Ethanol is like 6:1 A/F and methanol is like 8:1. Mix a large amount of it with gasoline and your A/F can be way off. In my original post, I said that alcohol would lower the CO but wouldn't help the HC. You got lucky with the NOX, alcohol isn't supposed to do anything for that.

 

[mackey]

I'm also in MA. There are some stations around here that will help you out. I'd give the girl $20 at the station that you are going to to only put one tailpipe hose on.. Either that or dump one exhaust and say it is single. Will pass that way. Mine did.