Smoke problems

Hello all,

I have a big problem in the technical inspection to get the vehicle registered here in Spain. They say my 6.2 1989 is contaminaiting too much. I would like to know if somebody has any recomendation to decrease the amount of smoke of the exhaust....

I have thought about decrease the amount of fuel in the fuel pump.

Any help is welcomed.
Thank you

run biodiesel and only test vehicle when fully warmed up.

back off on timing diminish fuel flow at injection pump control.

Later HMMWVs have some kind of particulate filter in the exhaust, maybe retrofit it?

Have you checked all your glow plugs perhaps you have a few bad ones.
What have you done to it since you bought it.

I just had my first technical inspection here in Germany, and was surprised how low the percentage of smoke particles actually was in my vehicle. Something like 0.5 % of the permissible value. So seems like a Humvee can be adjusted into a clean machine (wasn´t me, I got it that way) .

I guess the usual suspects are the injection pump timing, and possible problems with the injector nozzles.

I don´t know how biodiesel is mixed in Spain, but here in Germany, biodiesel contains a very high percentage of aggressive stuff which causes damage on gaskets unless the part is especially constructed for biodiesel. So most Humvee drivers overhere stay away from biodiesel.

The "filter" on later Humvees (A2 and on) is just a catalytic converter, not a particulate filter. I don´t think adding it would change much with regards to smoke particles.

I´d find a good workshop and have them check the injection nozzles, and play with the injection timing.

First thing is get injection cleaning fuel additive and clean system. Run a tank of this stuff, then use entirely new tank of only Diesel fuel without additives for the test. Run only fresh fuel for the test!

Second I would only let them test the vehicle after it warms up. Vehicle should be driven at least 1/2 hour constantly prior to the test.

Biodiesel is a great surfactant and cleans engines up BUT damages rubber lines with time. I’m not aware of gasket issues on any of my vehicles. Biodiesel cleans out your system very well but will require plastic fuel lines as anything rubber will be degraded.

I second the idea of going to a Diesel shoppe. Use an old school diesel shoppe with older people experienced in these types of non-computer engines. Let them tune the vehicle for the test.

Catalytic converters might not help you. I would not purchase any vehicle additional parts until after you let a Diesel shoppe evaluate your vehicle.

Best,

T

Hotter thermostat, 10% jet fuel, 10% unleaded and advance your injection timeing
about 2 degrees from spec. And after the test throw a quart of 10 weight oil
in there and next fuel stop filler up.
We have done that to big cummins, Detroit’s and cats. The power goes up
and emissions go down. Now will you get a million miles out of them?

sue said:

Hotter thermostat, 10% jet fuel, 10% unleaded and advance your injection timeing
about 2 degrees from spec. And after the test throw a quart of 10 weight oil
in there and next fuel stop filler up.
We have done that to big cummins, Detroit’s and cats. The power goes up
and emissions go down. Now will you get a million miles out of them?

Click to expand...

With all due respect..

Jet fuel is essentially Diesel, no?
On old Diesel engines "spec" is relative. Things get worn and loose.
I don't know so I'm not sure about oil as it might contain impurities or not burn properly.
I don't know so I'm not sure about adding gasoline/petrol for an emissions test.

I believe your results, BUT are they reproducible for the OP?

I think Diesel Mechanic is best shot here for OP

Close but with less lubericating property’s (oil)
that you don’t see oil residue on jet aircraft.
A little
soot maybe. If you do see a oily residue on your
next flight, take a later flight.

Hi all, sorry for the short answer but I am writting in the mobile phone. I have read all your answers. The smoke test read 6, while the maximun permited here is 2.5 I have done nothing since i received the truck in june, just some rides. The problem is that it is not registered, so i cant drive it in the street, only in the farm... i am going to check air filter, fuel filter, i have added an aditive to the diesel, and then i might tune the pump but i hate to do it cause it is a dangerous business i know i can burn the engine. I have been advised on a page that explains it: https://www.flashoffroad.com/Diesel/injectionpump/mechanicalpump.htm

Lets see.. i am worried. If i do not pass the test i cant register the truck.

Thanks to all for your help.

Willie

I have also received some typs from friends:

Remove the air filter for the test
With the engine running, clean the exahust with a karcher
Put a piece of wood under the floor carpet in the place where the throttle pedal rests when fully pushed. The idea is to limit the throttle

What do you think?

I am not big on a "mechanic in a can" fixes. What it could be or might be presents too many variables to second guessing problems. Easy answers off the interweb is just that easy. It's a hit or miss. Sure it's fun to play HUMMWV doctor, noting there is a lot of knowldge right here in the SS MASH unit. Going to refrain on "what's the matter, how do I do it?" here.

What I will say is to read up, just a little, on these problems. Easy step by step follow through to fixes and more important - learning. TM's, web sites, and your personal note book are a part of your rig.

This is the easiest read to follow > https://hummerhuren.files.wordpress.com/2013/01/hmmwv_test-diagnostics.pdf < If your serious about you rig, bookmark it.

Section 3 covers engine, timing and fuel... Smoke too.

Sometimes it is a trial and error or more a step by step to the final fix. Tools, time, logic, patience, $$$.

BEEHUMVEE, soon it will be a bumble bee on the road.

Now I am going to take a chill pill and see what happens, CAMO