yeah so i can't pass emissions, im wondering if any of you have any ideas.

Last month i went to get my 91 RS inspected, and i failed emissions, My hydrocarbon levels were like 350-something and they have to be 222. So that means im runnin rich, i think. So I changed my oil, anti-freeze, O2 sensor, plugs, spark plug wires, distributor cap, and rotor. I also bought a bottle of that guaranteed to pass emisions thing and ran that through. Now i and get another insepction today and I failed again, same problem. My hydrocarbon levels were 333 which was still too high. So i dont know what to do.

any ideas.

I guess the only other thing that could be wrong is my computer. Cause the inspection said my catalytic converters were good.

 

I think that EGR Passages w/ a lot of carbon build-up could effect that... lol

 

When I used to live in SoCal, I'd advance the timing too much an lean out the fuel pressure. ONLY DURING THE TEST!!! LEAVE THE ENGINE RUNNING, IF YOU SHUT IT OFF IT WON'T RESTART UNTIL YOU DIAL THE TIMING BACK DOWN!!! Stop at a parking lot nearby before you get to the test and adjust there. Hope it helps............

 

i just put in a new egr valve last year

does anyone have any ideas how i can fix my car to pass inspection, not rig my car to pass inspection

 

high levels mean one of two things: too rich or burning oil, you don't have to see smoke to burn enough oil to fail. check pcv, and breather system. if the pcv is stuck open you suck too many oil vapors into the intake, if its plugged excess oil vapors get sucked in past the breather tube hookup. Just because it rattles, does'nt mean its okay. Make sure you have a new breather filter or if you don't have a filter make sure the tube is claen and unobstructed. You did the tune-up, so now sheck the timing. You may have to clean the fuel injectors. IF they are dirty, sometimes they don't close properly and you get a slight nozzle drip. Extra fuel means high HC. Good Luck!! Remember, you're doing the hardest part of tuning, but if it runs good now you probably don't have any major problems. You have to sweat the small stuff in this case.

 

A sticking A.I.R. diverter valve can send air to the manifolds when it is supposed to be going to the cat. This will make the O2 sensor think there is more left-over oxygen from combustion than there really is, the ECM will put in more fuel, which will give you a rich exhaust.

Just a possibility to consider. Blown A.I.R. check valves is a good way to cause diverter valve problems.

 

How would you go about testing or checking the diverter valve and check valves? That might be my problem.....

 

yeah how would i check that, and /or fix it?

 

Get the engine warmed up, disconnect the A.I.R. hose (on the driver's side would be a good choice). If there's air coming out, it's going to the wrong place.

Make sure the vacuum lines to the diverter valve are connected and in good shape.

 

i know i sound like and idiot but where is the AIR hose located, or what is go into

 

Attached to the exhaust manifolds is a small steel tube manifold. Attached to that small manifold is a rubber hose. The two hoses meet at the front passenger corner of the engine at the diverter valve, a black cube-shaped device. A third hose goes to a tube that goes down to the catalytic converter.

 

WHOA! Hate to bring this thread back from the dead, but got a question about five7kid's comment:

"Make sure the vacuum lines to the diverter valve are connected and in good shape"

What vacuum hoses? The diverter valve for the coolant has a vacuum line on my 91, but there's no vacuum line going to the PEDES (diverter/solenoids for the AIR sysem). Am I missing something here?

Have a Great Day!!!


- Vern

 

since it back up to the top

I have now fail my emisions 3 times, and i have till dec 1 to pass or i get fined.

So so ive

-changed oil twice
-changed plugs, wires, dist cap, and rotor
-new O2 sensor
-tried the "gauranteed to pass emisions" thing

**failed 2nd time

then i took it to my mechanic and he

-changed vacuum hoses
-cleaned out my AIR system
-changed fuel filter
-and just kind of checked things over on it

**failed 3rd time


now my mechanic told me to just bring it to him and he'll mess with the timing and get it inspected for me

(he would but his machine is broke for that year car)

is there anything else i could do to help me pass?

maybe injector cleaner, it thottle body cleaner, or anything

 

What part of the test exactly are you failing?

 

HC levels have been too high each and every time, abd thats it

 

Check your ignition parts besides the ones you changed. I mean check the coil, module, and pick up coil. You may have weak spark which is causing an incompletel burn. Are you sure your PCV and EGR are functional?

 

havent even thought about checking my coils, how would i go about doing that, with an ohm-meter or what?

the egr i just changed less than a year ago, so i doubt thats the problem

the pvc is questionable, though i think its fine

 

Whats the rest of the levels?

Have you checked that the air pump is actually pumping air?

I'd consider replacing the cat(s). THere is no test to ensure the cat is working properly, except the emissions test. If your failing HC's i'm leaning twords your cat.

There is nothing wrong with your ECM. Too many really dumb mechanics like to swap out ecms when its obviously a mechanical problem somewhere.

Some of the things members have mentioned will skyrocket your NOx levels.

-- Joe

 

Another thing he can do is try running a hotter plug, but again, at the risk of increasing the NOX levels. But its worth a try.

-- Joe

 

Hydrocarbons (HC) (PPM): Hydrocarbons are the component of fuels that produce energy. HC emissions from a vehicle are basically unburned fuel. High levels of HC emissions indicate incomplete fuel combustion, either the result of a misfire or of low engine compression. Unhealthy levels of HC emissions result in a vehicle failing its Smog Check. Hydrocarbons are measured in parts per million (PPM).

i found that on the web. i would check the resistance of your injectors, they should be all close to the same range in ohms 12-17, anthing less than 12ohms i would consider replacing them. check your fuel pressure. that gaurantee pass emission stuff is a just a marketing gimic, all it is, is a cleaner, just as good as spraying a little bit of transmission fluid in the throttle body. its a really clean liquid that will clean up the internals of the engine. also check the tps and iac valve. if all else fails, run 5% ethenol in the gas.

 

make sure the vac line to your fuel pressure regulator is hooked up and not leaking. if the vac is missing to the regulator, it goes to full fuel pressure. computer should be able to compensate somewhat for that by decreasing the injector pulse width but might still run rich on an emission test.