Failed smog bad, need some help deciphering results. (1 Viewer)

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Hey guys, could use some help to pass smog in kalifornia.

I took the truck in recently to a shop because it wasn't idling, and they found junk in the idle circuit solenoid. Cleaned that out and it runs better than ever.

I had been running without the egr hooked cause it would stumble but the mechanic hooked it up and it seems to be running alright now.

Passed 2 years ago with decent results.

Failed miserably this time.

Anyone have any ideas or suggestions?
Truck runs better than ever, idle has never been more solid.
Does it look like it's running rich?
Would a lean drop help get those numbers down?

I noticed this tech didn't put the truck on the rollers, not sure if that matters.

Any input would be really appreciated.

Kevin
 
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Air injection working correctly? I had a problem when the air bypass valve was stuck open- bypassing the exhaust and blowing back into the air cleaner...the air injection system needs to dump air into the exhaust stream to cut down on the output concentrations...take off the hose going to the air injection manifold and rev the motor to about 1800-2200 and make sure there is plenty of air going to the manifold from the air pump. could be the pump vanes are shot, too, but you gotta have air. what kind of vacuum are you pulling at idle and what elevation are you at? lean drop always helps, as does new oil and air filter, and a hot engine(not overheating, but good and warm...)valve adjustment?
 

DFXR

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Your test is different from mine up here in the Bay Area - here I'm always on rollers and the NOX is measured as well. Possibly b/c I've been GP'ed before. But I just passed pretty clean recently so I can share what I know...

The not so fun advice would be to download the emissions manual and go through your system to see what's working and what's not. The AI system as mentioned above is very important as it dilutes what comes out of the pipe, and a lack of function could give you both high HC and C0, whether you're running rich or not. Search for member Spike Strip here and you'll find a link to the emissions manual in his sig line.

The other thing is to take a look at your cat and see if it's original. If so, you may be due for a new one. I had very similar numbers to yours after both a carb rebuild AND going thru the emissions system. Replacing my original cat with a new Magnaflow was the last thing on my list and it did the trick. The catch is that if you're actually running rich, it's not so healthy for your cat, so figure that out first. And a new cat will cost money, so try to eliminate other things before you do it. You can test the cat's function with an IR gun - it should be significantly hotter at the exit vs the entrance on a hot, running truck.

The third thing - denatured alcohol, which was NOT mentioned above by anybody. It does help, though it can spike your NOX numbers if you use too much. But since you're not getting tested for NOX, why not hypothetically consider it? The ratio I've heard about is approx half tank gas to 1 gal DA. I've heard you bring the truck in hot, test it, and then head right to the gas station to fill up and dilute. Though if your cat is totally shot, DA might not be enough.

Hope this helps. It hangs over your head when you're not passing, whether it's a DD or not.
 
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Thanks guys

I will definitely check the air injection system.

The cat is not original, so I have a feeling it's okay.

Does adjusting the carb, lean out the mixture only at idle or also at higher rpms?

I noticed I failed at higher rpms as well.
 
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lean drop is only for idle and off idle. the running mix is controlled by the main jets. I'll still vote for the air injection...but do the idle adjust anyway...
 
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E-85 gasoline is a great, cheap source of alcohol to help emission tests - no need to buy anything more exotic. Given the high CO numbers, I'd carefully check your air pump to be sure it's putting out some air.
 
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thanks guys, checked the cat, seems to be working as there's a good temp difference pre and post cat.

Will dig into the air injection system today, do the lean drop adjustment.
thanks guys

love this board!

pic of my truck , rover guy parked next to me at harbor freight this morning.
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If I recall, there was a really good smog test thread. I know Spike contributed to it, and it had lots of really good tips.

Here are a few:

Long drive on freeway to clean her out and get everything nice and warm, including the cat, prior to test, check the smog parts for proper operation, tune up, valve adjustment, fresh oil and air filter, E50/50%, etc.

I heard a couple of new things to consider recently:

Block the vents on the fuel tank to pass the tank pressure test and have a good gas cap also, as these will fail you.

If you are burning oil, use the new car oil with very low zinc and ZDDP. It will help pass smog, but change it out or add a ZDDP additive package to protect you engine right away

Also, go to a place that will pretest you, it's worth it. If they enter all the info in the computer and you fail, you will likely be labeled a "Gross Polluter", a bad thing that will require you to go to the Gold Shield smog test stations only in the future.
 

Spike Strip

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Kevin,

High CO and high HC low CO2. High CO is partially burned fuel, HC is unburned or raw fuel, so it looks like you're running rich or the CAT isn't working well with incomplete combustion. Your air inj is working, kind of, but % O2 should be higher, so the air pump, or check valves or anything in the AI system could be malfunctioning, blocked, etc... If EGR is not working, could elevate HCs.

It would help to know the NOx reading...

Plugs, wires in good shape? Easy way to test for misfiring cyl: On a running engine, pull one spark plug wire at a time, and if you find one that does NOT cause the RPMs to drop and engine to run rough, examine that spark path.

You have the Emissions manual, right?

Keep us posted.
 
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Thanks for the tips spike,

dug into it a bit.

Tested the ABV, by checking the hose going back into the intake.

Lots of air coming out, so it failed.

However, I pulled the tube that goes to the VSV2, and connected it direct to the intake and no more air, so the ABV works.

So I'm thinking the ABV is good, moved on to check the VSV2.

Broke, the frigging vsv2 nipple but luckily had a spare. checked it per the manual, and the vsv2 is working fine.

No power is getting to the vsv2 at idle to allow the vsv2 to open up and allow the ABV to operate properly.


I know the VSV2 is controlled by the Cat thermosensor, so I tore apart my interior as I remembered a loose wire when I was installing my tuffy console , thinking the cat thermosensor was unplugged.

i believe the green wire is the thermosensor, and I found it plugged in, so i think I'm okay there..

To see if the thermo sensor was bad ,
I pulled the plug and checked the vsv2 , no luck.
I pulled the plug, and used a jumper to close the circuit, (not sure if this is even how it works) to see if it would activate vsv2, No luck.

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So, by my logic, the VSV 2 works, The thermo sensor is plugged in, and when jumpered, no difference, So then this leads me to the emissions computer?

Also found this other wire under there that was cut and doesn't goto anywhere. Is this for some seat belt sensor? I replaced my seats with procars , so have no idea where this other wire goes.. any ideas?


Pulled the computer... and have no idea how to check it or repair it. Some posts mention to solder it, but what does that mean exactly. I've searched a bit and cant find any good posts on repairing the Emissions Computer.

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Anyone have any tips on checking the emissions computer, or fixing it?


Also lastly, there's this plug that's not plugged into anything near the emissions computer. Is this supposed to be unplugged?
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thanks guys, I could not own this truck without Ya'll... not sure what we're supposed to do as our trucks get older and parts are no longer being produced and we still have to meet smog.

thanks
Kevin

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I FIXED IT!
Turned out to be a bad VSV 1. I should have checked it sooner, but when reading the schematics, I didn't think VSV1 would affect VSV2.

Had a spare VSV 1 and swapped it in, and bingo! no more air being bypassed back into the air intake.

What a wild goose chase.... hope this helps someone in the future.

now to get this thing smogged!
 
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That is a lot of CO for the AI/catalyst system to handle. It is running rich too. Make sure that the air cleaner isn't clogged and that fuel is not dribbling out of the main nozzles at idle.
 
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That is a lot of CO for the AI/catalyst system to handle. It is running rich too. Make sure that the air cleaner isn't clogged and that fuel is not dribbling out of the main nozzles at idle.

thanks for the insight,

Picked up a tachometer to properly do the lean drop. hopefully that will lean out the idle mixture, will look in the carb, while idling to see if anything is weird, although I'm pretty unfamiliar with what goes on in there.

going to do a valve adjustment as well, before going in.
 

ToyotaDon

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FWIW, you are in an enhanced area according to the BAR, so your Cruiser should be tested in "loaded mode" on the dynamometer. As was said already, those numbers indicate a rich mixture, which needs to be corrected.
 
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You should not be able to see any fuel dribbling out of the main nozzles (which some people call venturis, but the venture is the hole that the nozzle sits in) at idle. That still wouldn't explain why it is rich at 2,400 RPM, but maybe you have a clogged air filter too. Maybe your power valve is stuck open? You would have to take the top cover of the carb off to see.
 
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You should not be able to see any fuel dribbling out of the main nozzles (which some people call venturis, but the venture is the hole that the nozzle sits in) at idle. That still wouldn't explain why it is rich at 2,400 RPM, but maybe you have a clogged air filter too. Maybe your power valve is stuck open? You would have to take the top cover of the carb off to see.

So looked down the carb while idling, and nothing dribbling out, looked very clean in there. both plates were closed. i gave it a little gas, and fuel dribbled out.

Air filter is brand new.

checked my plugs , they looked BAD. could this cause a rich condition? I'm assuming so by not burning the mixture fully?
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Could off timing also cause a rich condition? Thinking I should check that as well.
 

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