i've searched!!!

i have an 87 Turbo II.....here's the story:

so i take the car in for smog on Saturday it PASSES the visual test and the emissions test however theres anothe new machine that is they began using recently, its suppose to test fuel pressure or something like that....anyways the damn machine breaksdown so the tech tells me that he cannt pass me however i should not worry since the car already passed the emission test and they would have the other machine working by monday.

i come back on monday and the machine works now, but this time out of all the test i FAIL the emission test which i had already passed WHAT THE F%$@. so i dont know what the hell is going on?????

the tech tells me that he thinks that im running rich and that he thinks that i have a vacumm leak and that i should get the car checked, i honestly think the car is running fine.

my question is; what could have caused my car not to pass the test the second time around???

heres the list of mods for refrence:

3 inch turbo back exhaust
high flow car (note: noticed that i have no air injection to the cat from the air pump)
cone air filter
Fuel cut defender

the car is running bone stock, and i just did a complete tune up and replaced the oxygen sensor, i seriously dont know why it failed.

results:

HC (PPM)
MAX AVE MEAS
M1: 15 MPH 121 31 170
M2: 25 MPH 96 20 178
ANY HELP OR ADVISE IS GLADLY APPRECIATED!!!!!!!!!!!!!!!!!!!

 

So you have no air pump connected, correct?
If so that would be an auto visual fail....

As far as I know, that air injection system from the air pump injects air into the cat for a very important reason. The cat converter needs oxygen to be able to complete the chemical reactions, if it does not have enough oxygen it cant fully convert all of the gases.


Anyways, your running rich.
HC's are unburnt fuel.

Could be a number of things going on, but are the HC's the only thing that you failed on?

Your cat could be no good too..... But im sure that would make you fail for the other gases though too.

Do you have new spark plugs, fuel and oil + oil filter, and an air filter?


Do you take a long hard drive before going to the smog station?
You have to get your high flow cat HOT before you take it there, otherwise it wont lite off and wont help much with cleaning your exhaust gases.


What are the other numbers for the rest of the gases?

 

ok here we go......

-yes i have no air injection however the cat does nothave an inlet, yes its a sealed cat.

-yes the HC's is the only thing i failed, everything else was suprisingly good

-the spark plugs are less than 4,000 miles old, im 1,700 since i last changed the oil, fuel filter replaced 4,000 miles ago, the air filter looks pretty good to me but i'll clean it again.

CO (%)
MAX-----------AVE--------------MEAS
0.76----------0.10---------------0.07
0.65-----------0.09--------------0.19

NO (PPM)
807------------237---------------97
746-------------199---------------45

what do think/??? thanks for the help

 

we have the split air pipe for a reason. our cat is split into two parts the first part breaks down NOX into nitrogen and oxygen. the second part uses the oxygen from the first catalyst to break down our hydrocarbons. since our cars produce a very low amount of NOX(hence the reason s5 don't have EGR valves.) it needs the air from the air pump to get more oxygen to the second catalyst. so you need a split air pipe on there to pass. and as for failing visual its strange that you past the first time then failed.

 

yeah you have a point, however, i PASSED the EMISSION test the first time around and failed it the second time what do you make of that????


i think im just running rich,,, does anybody know how to lean it out a tad bit

 

well how new is your cat and had you been driving your car for a while prior to the first test?

 

if you went first thing on monday like drove the car straight from your house to the test station. and it was less then a ten minute drive that could cause you to fail to.

 

What were your CO2 and O2 readings?

Oxygen should be about 1% and CO2 should be between 12%-14%
The CO2 and O2 being high or low wont make you fail, but they help determine the problem with the car.




Is the cat you put on a 3 way cat, or a 2 way cat?

If 3 way then you need to get it really hot and go straight there trying to keep it hot then have them test it. Take a really hard 20 min drive.

If 2 way then you need a source of oxygen for the cat to complete the chemical reactions.

It seems like your running a 3 way though from the looks of things.


My porsche had a highflow 3 way cat on it, I failed the first time but that was because the cat was not hot enough.
The second time I drove the **** out of it and went straight to the smog shop, it passed perfectly fine.

 

im beginning to think that the car was not hot enough since the car was off while they tested 3 other cars, however the fact that the HC's where really high makes me think otherwise.

yeah i agree with you i drove the car from school which is like 5 minutes away and on top of that i drove it nice and easy, the the car sat for the duration of three other tests.

IM SUCH A NEWB about this car i have no clue how old the cat is, or if its a 3 or 2 way, is there any way of telling by looking at it.

i can provide a picture if it would make things easier guys

 

get an air pump

 

i have an air pump and its working, the air pump is not the issue, if you read my fisrt post you will notice that i said that i have no air pump INJECTION

 

Not much use to have a air pump not hooked up to a monolithic cat...

anyway, do the JRat emissions scam that is covered in the FAQ for FC sticky thread.

Either that or replace the cat with one that has the input and hook the air pump up too it.

 

ok , so i read the thread now my next question is this:

how do i do this????

"1. Turn variable resistor to full lean, or as lean as you can get and still run."

where is it located and how lean is it safe to run it in a stock boosted 87TII

i strongly believe that if i lean it out a tad bit and run it longer in order to let the cat heat it, that might make it.

so does anyone know???

 

When in doubt, change the fuel. Home depot's methyl hydrate and a tablespoon of acetone worked wonders on my 88 that was chronically failing....

 

thanks for the tip wilker's but i dont know if i want to throw those kinds of things in my car.



so those anybody know where this variable resistor is located and how i can change the setting on it to make the care run less Rich????anyone

 

the variable resistor should be on the passenger side strut tower on a bracket that has the boost pressure sensor on it.

 

sorry for being such a newb but...how do i adjust it??? and how much is it safe to lean it????

 

Variable resistor only effects idle. It won't help a twit when on rollers and the car is doing 15 mph/25 mph.

You say you have a airpump. Do you have a ACV? I care not if you do/do not have a split air pipe. You need a airpump and a ACV.