I have 270K on my 96 Dodge Cummins with an auto tranny. I bought it at 100K and I've never changed to cleaned the injectors. How many miles are the injectors good for and when should they be cleaned?

Bob

 

If the injectors work fine no cleaning is needed.

Symptoms for worn injectors are a haze at idle, rough running, sluggish cold start.
If you don't have any of this- smile and wash your truck.

If you got that, go get your injectors checked for pop pressure and spray pattern, adjust or repair as necessary.

 

I do have some haze at startup. When I get a chance I'll pull them and clean them up. I'll have to get some of the washers, so I have them on hand.

Thanks,
Bob

 

This is a diesel, not a gasser- no need to clean the injectors. (OK, they will be sooty and ugly, but after cleaning them they will look the same again after 10 minutes of runtime)

Diesel injectors like you have (before common rail) need to be pop tested. Then you know at which pressure the injector opens. If this is too low, the fuel will not be "atomized" properly, and not all of it will burn.
If pop pressure checks out, and the injector does not dribble fuel at lower pressure, the spray pattern needs to be checked.
Droplets too big will not burn completely, leading to haze. This would be a sign of wear on the injector tips. Holes washed out, needle worn etc. Then you need new tips and someone who will adjust the pop pressure correctly.

If you don't have a good diesel shop at hand you could look into aftermarket injectors, these will usually give a nice power boost and cleaner combustion if you select the right ones. (there are a lot of high power tuning injectors that will smoke a lot... and there are some that are optimized for a clean and efficient burn, and use technologies that were not available when your truck was built)

 

If the OP wants to stay with stock/OEM, it may be cheaper to get new injectors than to have the originals reconditioned by a shop. I replaced my injectors two years ago - the pump shop said they were popping about 20 bar below spec. Rock Auto had the best prices on new Bosch OE-replacement injectors at the time and was cheaper than the local shops could recondition my originals.

Alpine, what new(er) technology would you be referring to? Better manufacturing technology for tighter tolerances on hole sizes? Or redesigned tips with different holes/sizes for better atomization? The clean/efficient burn is of interest to me at stock power levels, as efficiency/mileage improvements are always welcome.

 

New tech means new materials and new processes enabling the mfg to create a better spray pattern and a tailored distribution of droplet sizes and velocities.

I have had mixed experiences with aftermarket injectors, especially from online sources. Testing "new" injectors before installing is necessary in my opinion, I had some with a spray pattern that would have roasted a piston if installed.
I prefer to have a reputable local shop do the work with stock parts, or buy from a manufacturer like F1 diesel.