cummins 12v sputtering around 2500rpm

Jeremy001995

Jeremy001995

diesel mecanic
hi, we just put a new engine in the truck..engine was removed from a truck 2 year ago and put in a garage.

its a 1997 215hp 12v..truck run great..idle smooth easy to start..run great until 2500-2800rpm, it start sputtering (white,black and gray smoke.. smell like fuel and eyes burning LOL)

i have stretched the spring in the OFV, got around 40psi of fuel at any rpm..it never go past 45 and never go down 35..

just re-do the timing set a 16* ,Timing is O.K. was doing it b4 at stock timing too.

FSS as been deleted and it is now a manual shut off, in good working operation.

engine is stock.

new fuel line from tank.

New Fuel Filter, Fuel Heater Bypassed.

what can cause this if the fuel pressure is good..? injectors?

tanks alot!!
 
Could be a dirty or Stuck injector .It doesn't start doing this until 2500 Try running some 2 stroke oil through the tank see if it help's some .
 
Is it worse cold than hot? Mostly clear up hot? I agree with jasonc, sounds like timing. Internal pump wear can also cause this. If the plungers are badly worn it effectively retards the timing because port closure doesn't happen when it should. Delivery valve wear or broken delivery valve springs can also cause similar symptoms.
 
Timing is good!! it only do it only when not fully warm up and cold. when at operating temp it rev fine!! got around 40psi os fuel but i think the lift pump is almost dead.. it started to made thiking sound.. lol
 
Jeremy001995 said:
Timing is good!! it only do it only when not fully warm up and cold. when at operating temp it rev fine!! got around 40psi os fuel but i think the lift pump is almost dead.. it started to made thiking sound.. lol
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If it does it cold worse than hot, then its timing or heat (compression) related. Like I stated above, it can be pump wear. Just because it measures correctly does not mean it is injecting fuel on time. Usually if its a heat or compression issue it will clear up within a few minutes of running when the cylinder temp comes up.
 
Chances are it has stuck or broken rings, or a scored bore.
Pull the oil cap and see if it has blowby, while either cranking or running.
Listen for a cranking variance while cranking it over.

Mark.
 
after running the truck one weekend it run fine now.. engine was sitting for 2 year.. maybe the ring was stick in the piston or something like that!
 
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