The ghettocamaro did not manage to pass emissions. I got a cat welded of dubious quality. The car has a new PCV valve and a newer EGR valve that seems to work as advertised.

Anyway the testing results were way not cool... Could someone explain them to me?

The HC levels seem to have shot up when the guy accelerated. The CO levels were outrageous, however, and so were the CO2 ones... The car gets great mileage... (~25 mpg highway, ~18-20 city)

:hail: Vader, grumpy and anyone else knowledgeable, please please help, I need to get this fixed in 3 weeks (I am leaving the country and I won't be back before the notice expires) otherwise its bye bye to ghettoness... :hail:

:hail: :hail: :hail: :hail:

So, anyway, here is the chart, see for yourself...

 

I feel like I am talking to myself, and I feel like a dirty crossposter, but here is some more info that might be helpful...

The IM240 requirements for model years 1986-1993 are
CO: 15.0 HC: 0.80 NOx: 2.00

My results are
CO: 55.1 HC: 1.50 NOx: 1.70

So, NOx is below crazy levels, meaning that EGR stuff probably works
Now, the insanely high CO and quite steep HC is what's worrying me.

On http://www.colostate.edu/depts/NCVEC...erters/az.html
I found out some calculated normal enigne-out CO (before it hits the cat).

My weight is 3403 so I should be getting between 16.0 - 17.0 engine out CO readings and the cat should make those really really low afterwards.

However my CO is way out there, above what it should be for my engine, and my HC is high.
The answer is obvious: I am running rich.

But how is that possible??
What worries me the most is the irregular spikes in the HC chart. Something's really wrong...

Is it just the sparks? I am definitely changing those and changing the oil.. Maybe that brand new distributor cap that I got for free might be of some use now... checking the timing?

Anyone been here before? Am i talking ?

Any comments are really appreciated, I have about 2 weeks to work on this..

 

first things first... general condition of maintence components... plugs, wires, cap, rotor and O2 sensor...

I/M 240 is at varying speeds and loads and I have not been fortunate enough to work with it...

check for codes and inspect carefully the condition of the vacuum lines...

are there any divability issues??? lack of power, hard start (hot or cold) rough idle, or surging???

and what is the fuel pressure in varying conditions??? like idle, steady cruise, uphill load, and full throttle...

after that its time for a real time scanner to moniter O2 voltage BLM and INT...

start with the simple stuff and go from there...

zroc

 

Your on the right track with respect to CO and HC.
CO is created in the case where too little oxygen is
present during the combustion cycle.
HC is simply unspent fuel.

Sooo...
Zroc is correct first things first...
Look carefully at the plugs and make sure you know
which one came from where. I doubt that all eight
will be uniformly tan. If you find a couple ugly ones
(black and wet) you're in the right area. If all are ugly
we might be working on something else.

The most common reason for failure is a corrupt O2 sensor

The good news is that there are decent gains to be had
via tuning. Think of this as an enforced performance
upgrade :-)

 

OK, my enforced performance upgrade is in progress.
I checked the fuel injector spray --- A-OK.
I scanned for codes:

Code 32.. meaning EGR solenoid trouble. (the valve is fine, I changed it two months ago, while I was working on some other stuff and when I inadvertently set the whole throttle body on fire....ah..the memories)

Could that account for the high HCs spikes and massive CO? Personally, I don't think so..

Besides, isn't EGR just supposed to reduce NOx.. I'm still passing with NOx.. they are not as low as they should be, but they are still comfortably below the legal limit..

 

BTW, no drivability issues (slight lag @ ~2000 RPM, engine needs a little more throttle to accelerate, otherwise it just stays there..is this normal??)

What's a simple way to check for fuel pressure? The fuel filter has been changed recently (~2 months ago). Idle is fine.

What constitutes a hard start..? On cold I crank it for about 5 seconds, no throttle and it start.. On hot, it starts even faster, but if I let go to soon it messes it up for a couple of secs.. this is normal, right?

If O2 voltage was all over, I'd be getting code 13, right? After I am done with other things, I'm getting that tested at a friendly shop for free..

Thanks guys for any comments, I really DO appreciate...

 

From the top...
Marin says...
>>I checked the fuel injector spray --- A-OK.

This means that you looked at all eight injectors with an appropriate strobe (timing light) and the spray pattern
was identical to the best your eye could tell

Plugs, you pulled all eight plugs and looked for differences
in the coloration, noting which one came from where and
they look ....

Sooo...
On to other things ...
>>Code 32.. meaning EGR solenoid trouble.
Could be a cause... If it is staying open too long it will
allow too much inert gass into the combustion chamber
reducing the burn rate of the fuel air mixture and leaving
unburned fuel air mixture. Remember that CO from
a chemistry standpoint wants to be CO2 it just could
not find enough partners... (free O's)

Fuel pressure...
Need a gauge... and a T fitting

 

>>I checked the fuel injector spray --- A-OK.

This means that you looked at all eight injectors with an appropriate strobe (timing light) and the spray pattern was identical to the best your eye could tell

Hm, actually I have a TBI setup.. (look at my sig in the posts above ) in my case, it just means I took the air cleaner off and started the car up. The injectors clicked very uniformly and the spray looked identical at idle and at various higher RPMs (including ~4500 RPM).

Should I push the matter further with the injectors or focus my efforts elsewhere?

Could be a cause... If it is staying open too long it will allow too much inert gass into the combustion chamber reducing the burn rate of the fuel air mixture and leaving
Wow, haven't thought of this... I'll check the hoses and try to replace the solenoid...

Fuel pressure...
Need a gauge... and a T fitting

Hopefully from my post count you can see I am still a total beginner with cars... could you elaborate a little on measuring fuel pressure (where would I put the gauge, where would I get the gauge, etc.)?

And, yeah, I didn't check the sparks yet...probably going to do it today...

 

oops sorry ...
But with TBI its even easier, hook up your timing light
point it at the injectors, nice stop action view of the spray
pattern...

I use some home made junk, easiest place for me
is at the fuel filter underneath the car...

 

Okay, today I replaced sparks #1, #3, #5, #7 with brand new ones and I torqued them to appx. 22ft#s. I have SIR, all the emissions stuff and A/C...so it's fun fun fun! And those manifolds sure get in the way...

But #5 is a b!tch, b!tch, b!tch, b!tch.. no wonder it was overtorqued, the torque wrench is pretty much impossible to get in there... For all but #1 I had to go under the car.. and yea, I used my share of universal joints, extensions and swivel sockets.. I swore at the car so much, this was the first time I swore at my camaro..

Anyway, frustration reigns.. when I get the passenger side sparks out (even more fun), I'll post the pictures up... I started the car and it runs allright (subjectively, runs better), so hopefully I torqued those things right and I didn't mess the plug wires up...

 

I PASSED!!!!

List of things I did (for future reference) :

1) Changed the sparks (each had at least 80K)
My idle dropped by ~100 RPM in idle and drive...

2) Changed the aircleaner element
Put the K&N lifetime warranty one in... The car became a little more responsive..

3) Changed the oil, changed the oil filter (Valvoline Maxlife)

4) Put Dynomax Walker Direct Fit cat in ($110)
Noticed my car couldn't peel the tires anymore... either my Kumhos (245/50/ZR16) broke in or (b) the cat is restrictive. I think (b)... that cat is going to be replaced by my 'flow enhanced' version

5) Begged the welding guy to completely seal my AIR pipe so it doesn't leak anywhere... (priceless)

How well did I do?

I passed in 31 seconds... I passed so fast I thought there was something wrong during the test

My HC levels were 6 times under the level required for composite fast pass and my CO levels were 2 times under the required level for fast pass.

No NOx, CO2 level (measures cat efficiency) was 1.00

In Illinois they run IM240 test under the newest, strictest standards for cars past 1988... mine is 1992, BTW...

Thanks everyone for the suggestions, I am free until 2004!!!




BTW, putting isopropyl achohol and various enhancers usually doesn't work on EFI.. TRAXION tried it and it still didn't help enough to pass.

 

Congrats.. !

Just one more thing ...
replace the 02 sensor...
Disconnect battery to reset computer...
You are nearly sea level the computer will relearn
spark advance and injector pulse width based on
your new hard ware...

Congrats again...