how do i find a bad injector?

[cumminsbomber21]

im having some wierd problems after blowing an intercooler boot off at 60-something psi of boost the other day. i get alot of timing rattle noise and rough acceleration around 2000 rpm under light throttle. when i mash the throttle it goes fine but i get black smoke like someone dumped a pail of fuel down the intake. also when i am slowing down the idle drops down to like 500 rpm and then recovers and idles fine. ??? any ideas are greatly appreciated. i have already ruled out the smarty and the hot juice having problems, i have 90 horse ddp nozzles (recently installed) s300 s400 twins studs and fire rings

 

[Joseph Donnelly]

For the 2003-05 Turbo Diesels, you could unplug one of the three electrical connectors at the head, while the engine is not running (the wires carry up to 50 volts). Once you see which pair of cylinders is at fault, you can remove the valve cover and remove one pair of wires at a time. Or, you could go right to the individual injector wires. You will get a trouble code, but you can use the Smarty to remove it later. Since other injectors may be “weak” the best approach would be to send all six to DDP for testing. They are a Bosch dealer and could sell you new injectors as needed.

 

[cumminsbomber21]

thank you, my engine seems to idle good but it seems like its louder. do you think that if i unplug on injector at a time, would that loud injector probably be the culprit? i also bought a new map sensor and FCA or something? the sensor in the fuel rail, whatever thats called. im gonna put my fass on today too, im sure i cant have much if any fuel pressure from the stock L P. thanks again.

 

[SShafranko]

What year is your truck? The fueling mods you have you should have an external fuel pump. In most cases with 90hp sticks and hot juice without the Smarty your stock lift pump will not be able to feed the CP3, and the CP3 will need to be modified to feed the injectors. Are you running hot juice and the Smarty?

 

[sag2]

The best way to isolate an injector is with the cap off tool. Unplugging one does not do anything for a stuck or dribbling injector. Mechanically stuck injectors still inject fuel when unplugged.

 

[cumminsbomber21]

i just got a plug tool today but im not sure how to use it, if you have any advice throw it this way. i put my FASS on today and that definately made a diference in throttle response and the engine feels happier. i have the hot juice hooked up kind of just for gauges, i dont think it does much compared to the smarty anyway and im running the smarty on 2 (soft catcher) with the timing set on 3 to lower the timing for the bigger sticks. even with that little bit of tuning i get a ton of smoke even with twins.

 

[TCDiesel]

i just got a plug tool today but im not sure how to use it, if you have any advice throw it this way. i put my FASS on today and that definately made a diference in throttle response and the engine feels happier. i have the hot juice hooked up kind of just for gauges, i dont think it does much compared to the smarty anyway and im running the smarty on 2 (soft catcher) with the timing set on 3 to lower the timing for the bigger sticks. even with that little bit of tuning i get a ton of smoke even with twins.

What is your sustain rail pressure @ 20/2100Rpms Pulling Hard?

 

[cumminsbomber21]

im not sure of rail pressure, i just ordered a quadzilla rpg3000. what does the FCA on the back of the CP3 actually do?

 

[cumminsbomber21]

i also tried the 2 stroke oil trick and that seemed to help some. ?

 

[TCDiesel]

The FCA, regulates the amount of fuel that enters the Body and the Pump chambers (3), when it is bad it generally generates a hard start and loping at Idle. In most cases additives and 2stk oil are preventive measures, and will only masked or treat the symptoms and not the cause. You need to know the rail Pressure. . to rule out some componets.

 

[cumminsbomber21]

thanks i changed the FCA and MAP sensors today and there was definately a change for the better. are injector tips for a 2005 the same as a 2006. i am starting to bet that i have a sticky or leaking injector, my truck only has 40,000 miles on it and the nozzles have about 4-5000 on them but they are out of my 2005.

 

[TCDiesel]

thanks i changed the FCA and MAP sensors today and there was definately a change for the better. are injector tips for a 2005 the same as a 2006. i am starting to bet that i have a sticky or leaking injector, my truck only has 40,000 miles on it and the nozzles have about 4-5000 on them but they are out of my 2005.

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