My 97 Dually just blew 61% on the NY emissions test. The limit is 40. The air cleaner is clean and the injectors seem to working properly since I don't have any complaints with preformace.
I was told I could get it to pass by adding 50% kero to the fuel. I will probably do that for the test but I want to find out how to get my truck to run cleaner so I don't have to worry about failing again.
Would adding a fuel additive(cetane boost-injector cleaner) regularly help?
I should mention I've had this truck for 5 years and this is the first time they tested for emissions.

 

i presume it failed particulate emissions.... to make a long story short, and assuming you're not burning lots of oil, you need more air and less fuel. advancing timing might help some also, but NOx emissions go up with advanced timing. plugged or missing cat doesn't help either. you can't win.

 

Hmmm, NY emissions test for a Diesel? I thought we only had to have a safety inspection...?

 

Upstate doesn't have an emission test. Not yet anyway...
Bulldog

 

I'm on Long Island, and havent had my truck "emissioned" yet. Inspection is up in November, so I guess I'll have to see

 

61%? What BOMB`s do you have? I`m running a set of POD`s and a slighty tweaked pump and my truck passed with 13% IIRC. Sounds like you need to back it waaay down or fix something. Hey greasemonki, what part of th island are ya at? I`m in Suffolk/Patchouge area.

 

I was very surprised my truck failed. The only smoke I see from the exaust is when shes cold or when I punch it out merging with traffic or towing my 37'
camper.
I read another posting on the same subject where low fuel press may be something to check into. But I don't seem to have any of the symptoms
of low press. She seems to have plenty of power and I have no problems with the engine stalling.
I should mention the truck is all stock except for a K&N air cleaner and the silencer ring was removed.
And yes....emissions testing for diesels has come to NY, Long Island at least.

 

Hmm
Do you get to run it or the inspection station tech? Static or running a chassis dyno?
If you run do not mash the foot pedal. Just ease into it to get your rpm from idles to around 2,200 rpm.
If a tech runs it explain it to them very simply: you and most diesel owners do not drive with it mashed. The engine revs slower so give it time. Engine torque is way to much.

Running #1 or Kerosene reduces the BTU or smoke content and raises the cetane which does help. It is an emissions trick learned from trying to clean up the old smoky Detroits.

 

I wasn't there when they did the test. Dropped it off and got the bad news. Emission tests on gas engines that I've watched they would gradually increase the rpm's.
I know when I "get on it" to merge with traffic I usually leave a light cloud of smoke where I left from. I never "mash" it.
When I bring it back I'll check to see what their procedure is. Thats after I replace my ball joints.(not looking foward to doing that)

 

Rookies will think a diesel should rev up as quick as a gasser and over fuel. Patience is the key to get past the fueling curve of too much fuel and not enough boost.

How often do you tow your trailer? A good run with a load keeps the cat cleaned of built up soot (turds). My (stock) truck smoked pretty good when cleaning the cat.

-John

 

pull the boost line from the back of your AFC housing & then take it back, it's a 1/2" brass fitting that runs from the AFC to the head, when doing that you eliminate any low boost fueling, it'll run like a dog, but outta pass emissions, might not be the answer you're looking for, but it should pass the test by doing this, Dusty

 

Fueling around:
The test is a snap test, they inspector will make 3 snaps and the avg of the the three is your result.

BobWatts:
You could try what Dusty said, or you could also loosen up the throttle linkage so your not getting full throttle, either/both should do the trick...but I still don`t see where your truck should be running anywhere near 61%, could be the way the inspector "applied" the throttle like Fueling said.

 

Yep, its the snap test here on LI. I would loosen up on the afc housing and slide it back all the way and back off on the star wheel a bunch.

 

I'm from a Town known as Oyster Bay, Long Island.... A lil Billy Joel reference for ya

 

I run a Daihatsu rocky as a daily driver,had it sixteen years.The last few years to help get it through the emissions test,I remove the air filter element and screw in the throttle stop on the pump so as not to get max revs.