Hey all, What is the easiest method of verifing a bad injector? I have a 2004 5.9 with 124K miles on her and all of the sudden she starts idleing like crap. Only mods are a intake air system and a older Bullydog Torq dog module. Rough and shakes like never before sounds like its missing almost. When you are on the road she drives ok but somehow seems off a little. I use the diesel power service in the grey bottle about every other fill to keep her happy due to the junk ULSD fuel. I just checked the oil level and it dosent seem to be on the rise or smell like diesel but may be a little thin but just changed it a few weeks ago. Last if i do need a new injector who has them cheapest? I may consider going to 50 or 60 hp nozzles while in there for a little better milage if it is worth the $$ to do it .

 

Remove the BDTD first before doing anything else. Did the issue start with this tank of fuel? If so it could be bad fuel. Try running some fresh fuel to see if it makes a difference.

Seeing any white smoke from the exhaust? Another sign of a bad injector.

MikeyB

 

Disconnected the BDTD. Refueled truck was down to about 1/4 tank. Drained water sep on airdog, only a few drops in it. went for a short trip no better and no noticable white smoke. Still real rough at idle. Checked oil again may be a little high but then again I never checked it after I last changed it. I just fill filter and add remainder of gal. and two more gal. for 3 total gal.

 

Do you think it is safe to drive the truck short distance 20 miles with a bad injector??

 

If it's not dumping fuel into the crankcase you should be fine.

MikeyB

 

thanks MikeyB, GOing to drive it minimally till thisweekend when a buddy supposedly has a device that checks the injector pulses etc. What do ya think about upgrading to the DPP 50HP injectors. IS it really worth it for mileage?

 

You've got a bad injector most likely, no codes or power loss on the road? It probably will be a dog to drive. If you're gonna do all your injectors truthfully I would do full injectors and not just tips, I would have them sent off and bench tested and EDM'd, and they will make a difference, especially if you upgrade the turbo in the long run. my bud had one foul on him and he had to make a 4hr trip home with it running like crap. He had heck because he had a 40' floater loaded down with some collars and a tree (oilfield hotshot)

 

Have you checked for codes yet?

 

Not showing any codes checked it three times. No MIL light either. Runs ok down the road almost normal actually but has just a slight stutter, miss or hesitation kind of hard to describe.

 

pm sent......

 

You may be having some fca problems if you aren't seeing any codes.

 

Sorry What is a FCA??

 

Fuel Control Actuator located on the back of the cp3 pump, held on by 3 stubborn bolts.

 

Ok Ill check it out. make sure its all moving properly and not binding or is it more of an electronic deal?

 

More electronic, its known to get sticky after wear and tear.

This is some info I found after a quick search on the web, for better understanding.

Can't say this is the problem, but it has been common for one to replace an old FCA and it really liven the truck back up idle and response wise.



FUEL CONTROL ACTUATOR

DESCRIPTION
The Fuel Control Actuator solenoid valve is located on the back of the front cover of the high-pressure pump. The solenoid is pulse-width modulated by the ECM and meters the amount of fuel that flows into the high-pressure elements inside the high-pressure pump.
The solenoid is inactive up to 30 seconds after IGNition switch is initially keyed to ON position to allow maximum fuel pressure to the fuel rail during cranking and start up. ECM assumes FCA valve control when CPS signal and rail pressure are within acceptable limits

OPERATION
The Fuel Control Actuator solenoid valve is a pulse-width modulated valve that controls the amount of fuel sent or delayed to the high-pressure pump elements inside the high-pressure pump. The ECM determines the fuel pressure set point based on engine sensor and rail-pressure inputs. If the actual fuel-rail pressure is too low, the ECM commands the solenoid to allow more fuel to flow to the high-pressure pump. This minimizes the difference between the actual fuel-rail pressure reading and the set point. The ECM will also operate the solenoid to delay fuel, reducing flow-rate, if the fuel-rail pressure becomes too high.
The FCA valve is commanded open by the ECM to allow the high-pressure pump to build maximum pressure (1600bar, 23,206psi).
Thus, rail fuel-pressure can be increased or decreased independent of engine speed