Emissions Issues and Accelerator Pedal Stop

[rustystud]

Honestly, just get the proper test procedure and show it to the tester each time you go in. No need to adjust anything. Just do the test correctly.

 

[WillWagner]

There are two criteria on the opacity test. One is the opacity, the physical smoke out the stack. In Ca, pre 1990 max is 45%, that's alot, it looks very black. Don't know what Az's rules are. The second is the "spread" or the consistency of the smoke, which, if the it is not done exactly the same by the tester, will fail. Here in Ca it needs to be, IIRC 5% or less. How is your engine failing, opacity or spread?

And yes, the procedure calls for snap testing from idle to rated while stationary. It won't hurt the engine, it is just going to the governor break rpm. This means that if the governed rpm is 2600, the engine will stop apx 150-200 rpm higher, 2750-2800 rpm...unless you've jacked the RPM up.

I stand corrected, 40% for opost 1991 and 55% pre 1991

 

[WillWagner]

Found this....

http://legacy.azdeq.gov/function/laws/download/1998/diessnap.pdf


A cut and paste from R18-2-1006, section H,

H. In area A, the inspection test procedure for diesel-powered vehicles shall be as follows:1. A diesel-powered vehicle with a GVWR greater than 8,500 pounds shall be tested with a procedurethat conforms to Society of Automotive Engineers standard J1667, February 1996, incorporated byreference and on file with the Department and the Secretary of State. This incorporation byreference contains no future editions or amendments. A copy of this referenced material may beobtained at: Society of Automotive Engineers, 400 Commonwealth Dr., Warrendale, PA 15096-0001. The procedure shall utilize the corrections for ambient test conditions in Appendix B ofJ1667 for all tests. The test results shall be reported as the percentage of smoke opacity. Emissionspass/fail determinations are as follows:a. Vehicles powered by a 1991 or later model year diesel engine shall fail if the J1667 finaltest result is greater than 40%, unless the engine family is exempted from the 40%standard under subsection (e);b. Vehicles powered by a pre-1991 model year diesel engine shall fail if the J1667 final testresult is greater than 55% unless the engine family is exempted from the 55% standardunder subsection (e);c. The engine model year is determined by the emission control label. If the emission controllabel is missing, illegible, or incorrect, the test standard shall be 40% unless a correct,legible emission control label replacement is attached to the vehicle within 30 days;d. Any vehicle that exceeds the appropriate standard fails the emission test. Beforereinspection, the vehicle shall have a low emissions tune-up as described inR18-2-1010(G);

 

[rustystud]

Found this....

http://legacy.azdeq.gov/function/laws/download/1998/diessnap.pdf


A cut and paste from R18-2-1006, section H,

H. In area A, the inspection test procedure for diesel-powered vehicles shall be as follows:1. A diesel-powered vehicle with a GVWR greater than 8,500 pounds shall be tested with a procedurethat conforms to Society of Automotive Engineers standard J1667, February 1996, incorporated byreference and on file with the Department and the Secretary of State. This incorporation byreference contains no future editions or amendments. A copy of this referenced material may beobtained at: Society of Automotive Engineers, 400 Commonwealth Dr., Warrendale, PA 15096-0001. The procedure shall utilize the corrections for ambient test conditions in Appendix B ofJ1667 for all tests. The test results shall be reported as the percentage of smoke opacity. Emissionspass/fail determinations are as follows:a. Vehicles powered by a 1991 or later model year diesel engine shall fail if the J1667 finaltest result is greater than 40%, unless the engine family is exempted from the 40%standard under subsection (e);b. Vehicles powered by a pre-1991 model year diesel engine shall fail if the J1667 final testresult is greater than 55% unless the engine family is exempted from the 55% standardunder subsection (e);c. The engine model year is determined by the emission control label. If the emission controllabel is missing, illegible, or incorrect, the test standard shall be 40% unless a correct,legible emission control label replacement is attached to the vehicle within 30 days;d. Any vehicle that exceeds the appropriate standard fails the emission test. Beforereinspection, the vehicle shall have a low emissions tune-up as described inR18-2-1010(G);

Like I said originally, the testers don't know what their doing.

 

[WillWagner]

I agree, they probably don't, they are just state employed monkeys.

 

[frank8003]

Use the Anti-Monkey bananas and steel wool method with ATF in the fuel tank.

 

[snowtrac nome]

Also, do not forget that your multifuel can run on fuels other than diesel. I went to my emissions test (long story) with a tank full of regular gasoline. Much less smoke.
Note that it is YOU who tells the DMV that this truck is a Diesel powered vehicle. Says who? It could equally be a gas powered truck. Runs fine on gas.
In my case, they could only test diesel trucks, not gasoline ones, so....

We call them diesel engines the correct name is compression ignition engines. Regardless of the fuel type the testing is the same cut your fuel by 50 percent with mogas and your exhaust will dramatically clean up. I would not go straight gas as it can score the cylinder walls and it will be hard starting. I was in a pinch in Korea once and had to run straight gas in one it worked but was under powered I was amazed that there was just about no smoke though.

 

[frank8003]

Gee
"I was in a pinch in Korea once"
Maybe one would listen because that was before one was even born.
But, Whatever..........................

I would tend to listen to that in the post 27........................
Or............... I was in a Pinch in Nam once,
or Thailand, Cambodia, or anywhere near that trail .....
Or I was in a pinch in the sandbox once.
Our trucks are good.

 

[snowtrac nome]

When I was in the sand box every thing was jp-8, in the 80's we still ran gas and diesel. the duce was used for fuel support in the field, we had lots of gas for generators and almost none for hmmwv's. We pumped the duce tank, loaded it with mogas and took off to get more diesel. As a young private back then I only read data plates not the tm's where it was recommended you mix the gas with a diesel product. the point being made is you can mix in some mogas and clean the exhaust up for testing purposes, and you aren't doing anything sneaky to pas the test because the engine is still running off its intended fuel source. For emissions testing there are 2 types of test one for spark ignition engines and one for compression ignition engines, the exhaust is tested for different gasses. Adding a thicker product like mystery oil or engine oil is not going to clean up his particulate matter. Adjustments in the pump slowing rack movement to match the boost will clean it up. Cummins used a variant of that in the 80's and truck drivers hated it because the engines revved so slow they had to plan way ahead to build boost before a hill most drivers had it removed or added propane injection to get around it.

 

[Floridianson]

So what was the out come did you get it inspected?

 

[Flyingvan911]

I think most guys have posted multifuel opacity results of around 14% or so. My friend Stagg put his truck on a dyno with emissions test for fun in Ohio and they tested it by whatever official procedure they use. The results were that his deuce (per pound of vehicle weight) put out less pollution on average than a modern computer controlled car.

 

[rtadams89]

So what was the out come did you get it inspected?

Mine passed as it always has. It's never been an issue of passing. The problem has always been that doing the test as described in SAE J1667 (which is the procedure AZ follows) requires me to "move the throttle to the fully open position as rapidly as possible". When I do that, it produces a very short lived, but significant soot cloud that then coats the opacity tester being used and causes the zero value of the tester to drift too much between the three repetitions.

It seems the employees are doing the right test procedure (in terms of putting the opacity sensor on the stack and having me floor it 3 times), and if the opacity reader actually works all three times, my truck passes. It seems the only way to not mess up the sensor (which causes the test to be invalid) is to ramp the engine up fast enough that the tester doesn't yell at you, but slow enough that the engine/turbo can spin up before you just dump a bunch of fuel in.