My AZ emission test..............

[BearTrap]

I’m trying to pass emissions here in AZ, and here’s my setup:1990 240KA24E – rebuilt 20k miles ago (passed MO emissions at the time) - running 92 octane on about 9.75-10:1 compression- bored cylinders with 90mm pistons- shaved deck- .402/270 degree performance cam- Port/polished head- 550cc(?) injectors- Walbro fuel pump- MSD ignition/coil/wires- Injen intake- Etc….

Preliminary check of systems: Good spark to decent plugs (a little burnt; but not bad), original cat (I know). Cause of the cam it’s rollin hard at idle, little accelerator hesitation at low rpms, kinda fumey when running still; but not smoking. Other than that, it’s running like a bat outta hell.

My emissions report here in AZ in grams/mile:

My car vs AllowedHydrocarbons 2.56 1.00Carbon Mono 70.11 12.00Nitrogen Oxides 1.38 2.50

Since the test,Plugs – Old ones were a bit burnt; but nothing too bad. ReplacedO2 Sensor – I’ve never seen one before; but it looked alright? It was light brown; but not black/carboned or damaged. ReplacedWater Temp Sensor – ReplacedCatalytic Converter – I don’t want to replace it yet. I’ve read that the cat can help if I’m close; but if I’m waaaaayyyyy over, it might actually make it worse.

What do you guys think? I’ve been thinking the cam/fuel setup could just be shoving in too much gas; but, if I have good spark/timing/compression what’s the problem? I know with a cam has low vacuum/high fuel volume at low rpm; but would I not be burning all of it? If I’m not burning all the gas, wouldn’t my plugs and o2 sensor look crazy black, burnt, or sludgy? All four plugs were uniformly light brown and were sending a good* spark when tested.

Thanks for any advice. I love my car and would hate to have to put it in storage till I get a house….No plate = No drive and no park

[r3v_v3ng3]

is your car tuned for your setup? or is it just a base map tune? do you have a adjustable fuel pressure regulator?i suggest getting it street or dyno tune cause its running rich. that way you know the real a/f ratio of your vehicle also your fuel system is actually overkill for your setup unless your planning to use force induction later. sr20 370cc injectors is probably your best bet

[BearTrap]

Are you talkin ECU tuned? I haven't done anything at all to the ECU which brings up the issue that I don't know what my A/F ratio is. What kind of shop would do this? Is it pretty much a plug in and tune, reflash, chip, new ECU?

I took the adjustable sr20 regulator off a while ago, so it just has the stock one on now.

[Oo_Skyline_oO]

new masterflo cat -100 bux, install it and a new air filter and it will more than likely pass

[BearTrap]

Air filter has just been washed since it's an Injen cone. I wouldn't think the cat would help that much would it? Also, do high flow cats limit their filtering/converting capabilities?

[r3v_v3ng3]

new masterflo cat -100 bux, install it and a new air filter and it will more than likely pass

it may pass but barely and then will kill your converter right away.you can look around the internet for ecu chipping with base tuning for your setup. then go to your local tuning shop and tell them to fine tune it.

high flow cat will sorta limit it but it shouldn't to where it won't pass smog. i used it before on a honda and it passed.

[r3v_v3ng3]

wait, you passed emissions before with the same setup? oh thats a different state. maybe they're different smog testing

[BearTrap]

Yeah, I passed in MO about 6 years ago. Then college in good ol no emissions arkansas. Now i'm in AZ.

r3v_v3ng3So i'll need to get a chip for them to tune it for my setup? They can't tune my stock ECU?

[Cone Junky]

You're running way rich.

The CO is unburnt fuel and the HC is partially burnt fuel.Just by the fact that your CO% is 6X the limit, I would find a way to lean it out. Even a controlled vacuum leak could help. Just be careful of being too lean, then your NOx will hit the roof.

[BearTrap]

What do you think about just putting in the stock injectors? or the 370s? Aren't the stock ones for ka24e 270? I know I replaced the injectors a while ago, and I would say I'm 50/50 on if they are the 550s or not....? I'll check the part #s when I get home. If I have working 370s, I would hate to replace them thinking they were 550s.

I'm trying to think through this..correct me if i'm wrong cause I'm a little rusty...My performance cam allows more air/fuel to get in the combustion chambers. However, additional fuel is dependant on additional air (which I'm not getting copious amounts of since it's N/A). Therefore, there isn't a need for larger injectors because there isn't alot of air coming in? So why the heck did I even get a cam or larger injectors if I'm not going turbo?

[Cone Junky]

Larger injectors are pretty much useless on an n/a motor, but a larger cam is almost always beneficial. It's more than just how much the valve opens, but more when the valves open.

Is the AZ test an idle test? If it is, you'll need to put the stock cam back in to pass. I had a wild cam in one of my VWs, the idle emmisions were attrocious, but it cleaned up just fine and passed under load (15mph and 25 mph tests).

[BearTrap]

Gotcha. I'm still a bit rusty on this stuff, since my car has been in storage for so long.

I was trying to snoop around as much as possible during my emissions test, and they had the car on the dyno idling for a while, then shifted through the gears, and then ran it out in 5th I think. The guy was shifting at like 3k rpm, who the hell does that?!?! My vacuum is so low under 3k, no wonder I failed miserably.

So, I'm thinking the cam has got to be swapped for the stock one, stock injectors, and a new cat......Agree?

By the way, will the timing have to be adjusted when I put the stock cam back in? I'm racking my brain trying to figure out if it will have to be or not.

Thanks again, I appreciate all the help I can get.

[Cone Junky]

Personally I would try the injectors and cam first. But then again, I only pay $20 per test, so I don't mind trying the minimum first.

Your ignition timing should not be effected by the cam change, but I always like to double check anyway.

[BearTrap]

Sounds like a plan, I'll give it a shot. AZ is $25/per test, so we'll see.

Thanks again, and I'll let you know how it goes......