brother just bought a 1995 dualy with a 5 speed has a 175 pump on it been running fine then all of a sudden it started missin real bad #3 injector port outa the pump isn't putin out any pressure, (that's the dead miss sound doesn't change when I open injector line) but what is weird to me is that it seems to run a little better if I crack #5 injector line

 

1,3,5,6,2,4 is the fireing order on the cummins, if number three is missing and you crack number 5 then you may not hear the miss as distictivley. But if the Injection pump is not pushing fuel to the injector that would cause a miss, its not gonna gush out of thir like ole faithful either. I would check fuel pressure and maybe check the injector its self..

 

I would change fuel filters ... Fill them up with ATF ( dextron 3 is fine, dont use syn. )

If this dosent help... one of your delivery valves is comprimised ... its not rocket science feel free to take the delivery valve out ..... just be careful it is spring loaded, use the appropriate socket - get from cummins or tool truck ....

clean it out .... you can do all of them - not a real bad idea

keep posted

 

Im gonna ask why fill them up with ATF? I know the whole lube the injectors story, but I would not fill the filter plum full with atf. Its not the lack of lube that kills these injectors its the dirt and water and lack of fuel pressure.... But start simple. If you have not changed your fuel filter in the last 10K then replace it, and check. If the problem persists check you fuel pressure from your lift pump and make sure its feeding the Injection pump adequatly. Then if you have enough pressure then move on to injecotors and the injection pump... EVen look for fuel leaks..

 

I have checked filters and filled em up with atf even the screen on the lift pump wasnt realy dirty, but now it appears
im get air from # 3,4,5 injector line u cant bleed it out it never goes away but # 1,2,6 are like normal can a injection pump put air in the lines

 

Atf is slightly thicker and draws a better pull and is less likely to become agitated with air bubbles ..... and it has plenty of detergents that can help clean out fuel system and lube at ths same time .........

I have been running about 1qt per fill for about a year with great results ....... when I switch to any other fuel boost or cetain boost ... I loose almost 1 mpg average .... speeks for its self in my experiences .....

 

Questioned answerd thank you...

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You know how many times Ive had trucks come in and the driver said he checked his filters? or even tell me he cleaned them? But if you have not replaced the filters within 10K replace them. But if you have and your haveing air in 3.4.5 injection lines either you are sucking air somewhere in the fuel system or you have internal problems in the injection pump.

 

I have been seeing a lot of injectors sticking open. It kills the injector next to it. Ran long enough the carbon now in the fuel system kills the injection pump.

I work on very few cummins, but JD, Ford, IH, Zetor, Mitsubishi, Perkins are all having this problem so I would think Cummins would be no different.

 

Yeah I would toss some filters on a dn fill with atf .......hopefully it will help to break loose what ever is goin on ....... also ..... check the torque on ur delivery valves ........ might want to have those lines pressure tested if filters amd such don't clear it up ......... but do keep us posted ...

 

Yes keep us posted. Generally when someone runs with a stuck open injector they dont kill the injector next to it or the injection pump they generally burn a hole in the piston... Or wash the cylinderwalls out...