3406 B failed emissions in NY

You're right, I just started driving in Nov 2014.....prior to that I spun wrenches for all my adult life....but yeah, you're right. As far as V-8 diesels, yeah they were before my time....thank goodness somebody figured out how poor of a design they are for dependable heavy duty use with small rod bearing surface area and the like. Either way, every engine in the last 30 years I've seen is governed from the factory. The data tag will tell you where it's rated whether it's a 2100 rpm 15l or 2600 rpm 8l.

 

If you get a good picture of the pump, zoomed in, I can tell you which is the throttle stop. It will be in the linkage of the main rod coming from the pedal.

 

It wasn't till the late 90s that mechanical controlled engines completely gave way toelectronically controlled. Detroit started in the late 80s but cat offered mechanical until at least 96. I had a 96 short hood Pete with a 425 3406B cat in it. All stock.

 

Sorry Rank not real familiar with the Cats, use to adjust the O'l mechanical Cummins with a Allen wrench behind the cover at the throttle shaft on the pump. Did our 1988 International bought 2 years ago. It took fuel so slow you lost speed like crazy on a hill. It would just give a hint of smoke after I adjusted it, before it was heat waves. Come to think of it I did that adjustment in DC by the anacosta River, Tom took my pic by the truck under the bridge. Think I put that pic in "Pics from my past" down in trucker pics. Hope you get it squared away, wish I could do more to help.

 

Whats that have to do with a governor or not? tony is saying it should have a mechanical governor on it. I agree with him. Like he said it should be 1800 or 2100. Im not crazy about the snap test either but it's not going to blow up an engine on the spot like some people here think. There's a diaphram in the fuel pump that controls the rack when you snap the throttle open. It prvents the fuel pump from dumping too much fuel into the cylinders when there is low boost. Thats what happens during the snap test with no load on the engine. An experienced cat mechanic can set that to kill a lot of the black smoke on a snap test.

 

there is a hi idle screw on the back of the governor housing, the cover is oval shaped with a 1/4 inch bolt holding it down, the screw it self has a 3/4 head. Most A,B,C Cats were set to run 2100 full load, 2380 hi idle.
There should also be a Air fuel ratio chamber up high on the governor housing, with a screw and a lock nut, turning this screw in means less snap smoke, and maybe slightly slower acceleration. only turn this screw in enough to control snap smoke or you might limit rack travel.
These engines will rev to 3000 rpm under load without damage, unless they are really loose already, Free revving is hard on a engine at any time.

 

Heard the 3406 valves start to float at 2400. Mine will rev to 2700 but only 2400 under load.

Most mechanicals came with the stop bolt on the floor under the fuel treadle. That's the first thing every driver tossed out.

 

To say it won't blow is crazy you pop the throttle many times tuning a pump I know this, but I drive with mine set in kill mode and there's no inexperienced idiot trying to give me a ticket gonna do it.

 

All diesel engines have a rpm governor of some sort.Engine manufacturers wouldn't build an engine without it,it would be destroyed in no time.I'm not talking about a road speed governor,I'm talking about a governor that limits high idle,and rpm's under load,among other things a governor does.Now people can adjust them,monkey with them,and screw with them and virtual make them useless,but it will only harm and wear the engine out prematurely.When it comes to what your high rpm's should be,the factory knows best.And V-8's,V-12's,V-16's,Silver 92's,3408's,NTC Cummins,6 71's,318's diesels,etc.,etc.,etc.,all had governors.
And talking the stop bolt out from under the throttle pedal only lets you bend the throttle linkage,the governor,if hasn't been screwed with is still going to control your high rpm's.