CA Failed Smog

[DarkLordFreeman]

Comprehensive Visual Inspection: PASS
Functional Check: PASS
Emissions Test: GROSS POLLUTER

15MPH
HC(PPM) : 293 (max - 83)
CO (%) : 5.50 (max - 0.53)
NO (PPM) : 345 (max - 799)

25MPH
HC (PPM) : 272 (max - 65)
CO (%) : 5.15 (max - 0.44)
NO (PPM) : 477 (max - 738

I took my 1987 325e in for a smog test today. These are the results. The engine is stock form. Spark plugs replaced. New air filter. Basically i failed miserably. I drove the car all the way there, a 10 minute drive. Puffs of black smoke did come out of the exhaust when I got to the station, not heavy ones and not before. I did a search, summing up vacuum leaks, O2's, and it has solved most everybody elses problems. I did not find any information on vehicles failing this badly though. So the engine is running very rich. :oops:

[davesmystery]

Well, there could be a bunch of stuff, especially on an older car. Not sure what the history of the car is, but here are the basics:

Adjust your valves (and replace valve gasket/rocker plugs), there's tons of guides. I just followed one and did mine for the first time, super easy once you get the hang of it, but be methodical and plug the drain holes!

Replace plug wires/distributor cap/rotor if they're old (find year stamp and look for corrosion). Mine were original to the car and had to be changed. Go with OEM here, the cost is worth it.

I think your eta is a 3 wire o2 sensor so do a search for the ford mustang o2 sensor 3 wire splice/solder. This is huge, a bad o2 sensor will cause all sorts of problems. The Ford o2 sensor route costs you about $30 and works just as well as OEM.

Also, check intake boot and other hoses for tears. Put clamps on hoses if there aren't any, etc. Read up on how to check your Air Flow Meter (AFM), your Throttle Position Sensor (TPS), and Idle Control Valve (ICV) to make sure they're functioning correctly. And, I know it's kinda cheesy, but a lot of people swear by the CRC guaranteed to pass (and other additives) to help clean out the fuel system.

Once this is done, do a retest. If it still fails, look at your cat and fuel system (injectors, fuel pressure rail, etc.).

In the cases where a car fails badly keep in mind it could either be a lot of problems in tandem or one huge one. Hope this helps, there's a ton of information about passing emissions on r3v.

[efficient]

get the proper thermostat for your car and also the temperature sensor. if you have a lower temp thermostat your engine will never get to its proper temperature and will run cold causing you to run rich.
also drive your car for more then 10 mins to get the cat hot

[!kid]

Get your injectors professionally tested and cleaned. with numbers that high, you got some problems.

[jlevie]

While it is possible that there is a single cause, I suspect the multiple contributors. What I'd do at this point (acknowledging other suggestions) would be to:

1) Have a smoke test run and fix any leaks. If significant leaks show up immediately, those will have to be fixed and the test repeated until 2-4psi of smoke pressure can be held for at least five minutes with no leaks.
2) Replace the ignition wires, distributor cap, and rotor. If the plugs aren't NGK ZGR5A, replace with those.
3) Adjust the valves.
4) Replace the O2 sensor with a new OE part (not a hacked in substitute that may not work exactly right).
5) Check rail fuel pressure, verify operation of the controls for the cold start system, and
check to see if the cold start valve is leaking. I don't know the mileage, but if over 100k I'd pull the injectors and have them professionally cleaned, rebuilt, and tested (I use RC Engineering).
6) Check to see if the engine is operating at normal temperature (80C) with an IR or contact thermometer by measuring the temperature of the head and tstat housing.
7) Check The ECT sensor to see if it has the correct resistance for the temperature and then check at the DME connector to make sure the DME can see the sensor.
8) Do a back pressure test on the catalytic converters. If the engine has been running this rich for a while there is a chance that the converters may have overheated to the point of partial melting due to the excess hydrocarbons.

After doing all of this, and repairs as indicated, I'd run the car for a while monitoring the condition of the plugs. The plugs won't tell you if the car will pass smog, but will certainly tell you if it running so rich as to fail. The odds are pretty good that the above actions will find and fix the cause of the high HC, but it is possible that the DME or the AFM could be bad. I'd save those for last.

[DarkLordFreeman]

The car has been sitting. for 1 year before I received it from my brother. Only the car did not have light black smoke coming out of the exhaust pipe. It only came out when the guy was testing the car. So I guess I took the car in for smog a bit early, but it still failed badly.

Is there a chance of mechanical problems? Not sensors/injectors/leaks? I did adjust the valves before I drove it over.

[DarkLordFreeman]

I also pulled the plugs after driving the engine for a little bit - before bringing it in - and they showed good signs of burn. Whatever the color they should be, I do not remember what it was but they looked good. They were not solid black or like wet or anything.

[jlevie]

Correct plug color should be a light brown.

[DarkLordFreeman]

I should have more information about a diagnosis tomorrow.

[DarkLordFreeman]

Got a call back from the shop. They said the MAF looks to be bad/adjusted. There is a torn intake boot, which is a leak. but they said the issue is looking at the MAF sensor.

Would this bad MAF cause fail numbers as bad as these?

[kronus]

e30s don't have a MAF, they have an AFM, which functions completely differently. A misadjusted AFM will cause mixture problems, for sure, but if your shop can't tell the difference between an AFM and a MAF i might want to get a second opinion.

[DarkLordFreeman]

^^Just my own typing error. *AFM*

They said there is a good chance the AFM (seeing as how it was broken) would cause the car to fail smog. It is just the numbers are bad. Very rich.

Are these AFM's adjustable?

[kronus]

that could certainly be the AFM.

vacuum leaks (torn intake boot) will make it too lean, but if it's got leaks AND it's too rich, AFM is most likely out of whack.

also you should verify that your cold start injector turns off after about 30 seconds from a cold start.

[DarkLordFreeman]

The AFM (from PO) in this car now, was apparently broken and then glued in place? I am not with the car to look, but this is what my mechanic man said on the phone.

So it was glued back in place - but the man did say that a new one is needed, and with that it should straighten out the numbers, and the vehicle should pass smog.

Is this AFM unit adjustable?

[kronus]

yes, AFMs are "adjustable", but mostly everyone says to not fuck with them, because they are set to spec when manufactured.

the glue your mechanic is talking about is for the AFM cover - the plastic cover is typically silicone-sealed in place, so the fact that it was glued isn't abnormal, but it's a sign that someone probably took it off and messed with the adjustment inside.

before getting a new one, you should get in touch with someone local to you and borrow their AFM to see if it'll run better and less rich.

where in CA are you?