I think one of my injectors is going out. This started about 6 months ago. When cold, it will idle rough occasionally and smoke a little but goes away after about a few seconds. Oil level is fine. Truck did this a few months after I bought it new in '06 but I ran Howe's Meaner Cleaner through it and it went away. That trick isn't helping now and 2 road trips over the last few months pulling the trailer hasn't helped. I did average 15.6 mpg with a best of 16.9 pulling our '65 Olds Cutlass on an open trailer round trip from LA to Reno and it pulled the passes on US 395 like a freight train. Seems to be smoking a bit more than usual, even when on stock. Just serviced about 3000 miles ago. Truck has 80k on it. Any advice? I tried to look on F1 site but it says under construction. Does anyone know of a good diesel shop in the LA area?

 

I had an injector go on me a couple months ago, It would smoke a lot and run really rough for about 10 mins then clear up and be fine for a day or so. It was covered under warrenty so it was replaced. Quess it can run about 1000.00 if not on warrenty. Good Luck

 

Try unloading the Smarty and see if it goes away.

Dave

 

Done that, while not as bad, it still does it.

 

Does it have any codes on the CPU? You could also OHM test injectors. Its easy just remove valve cover and test all injectors with OHM meter. That's the only way I found out my number 4 injector was bad

 

No codes at all. I'll have to go buy an ohm meter. How exactly do I do test them? FYI, I'm not good with electronics so please explain it simply, lol.

 

Stop fighting it, get a set of 60 or 90 hp injectors. Just did mine with 60 hp ones at Hotrod Diesels in Hitchcock, TX.

Truck starts like new now.

 

There are two sides to the injector. The electronic side and the mechanical side. A failure on the mechanical side may not leave a code, and will not show up as a failure during a continuity test. An over fueling injector can certainly be a failure on the mechanical side. When it is smoking and misfiring cold, you may be able to find the colder cylinder with a heat gun. Other wise tipping the exhaust manifold and starting it cold will reveal which cylinder is blowing all the smoke. Cummins does not mention this, but you will find it easier to ID which cylinder if the fan is not turning.

 

This is how I tested mine. Its real easy. I took off the 10mm screws for the valve cover and there are 6. On my OHM meter, I set the resistance of 200. I really dont know what that means, but when going through all the settings on the OHM meter, that gave me the closest result to what I was looking for which was a .9 or a little greater. Then you just go one by one. I was reversing the Pos and the Neg and the readings were the same. Pay attention to the readings. I had both batteries disconnected, and the wires to the valve cover disconnected also. On mine, i started with a .9 of resistance and then it would go up to a 1.0 and the greatest was 56.8. That 56.8 was the one that stood out the most and figured it was that one with the problem. Now I had never done it before, but with much thanks to CARL 48.

 

That would be fine except I live in Kalifornia I am leaning towards the F1 mpg ones, 20 or 40 hp I think it is?