Ddec V rough idle help (DDDL snapshots)

Swapped injectors #1 and #6 and the numbers now moved to #1 so I ordered a new injector. Odd thing is now #2 is showing just as low.

 

Reseal them all. If any compression is getting passed an injector seat, it will aerate the fuel (and soot up your filter). Air in the fuel can make other cylinders show bad on a cutout test. To verify, pull the return line and put it in a bucket of fuel, start it up and look for bubbles. Stab the throttle a few times. If you have anything more than a little fine campaign type bubbles, you're getting air in the fuel system somewhere.

When I suspect a bad injector, but not 100% sure, I'll do what you did. Swap them and see if the problem follows the injector. I also check all the rest with a hand vacuum pump (Mityvac), pull a vacuum on the tips with a short hose. If they do not hold a vacuum, they are not seating fully and should be replaced.

EDIT, I missed the pics of the second set of tests (pic didn't load for some reason). I have a hunch that all of your injectors are starting to clog up. Typically with a poor spray pattern, they'll improve with the higher RPM test. Your idle #'s are all over the place and look pretty crappy. This could also be yet another indication of aerated fuel though, so definitely check for air in the return line. If you find air in the fuel, reseal them all and replace #6 and retest. If there is no air in the fuel return, I'd seriously consider a whole set of injectors.

 

I noticed the weather pack gromet wasn't in place on the connector to the injector. Could oil getting into the connector cause any issues?

 

Doubtful on oil in connector. Grape is correct. If you are able to afford all 6 injectors, replace them. You will think that you are driving a totally new truck. At very least replace all o rings on every injector.

 

All injectors are 4 months old. At this point im in parts warranty territory.

 

Swapped the one injector out, of course it's -20c outside and I did it on the side of the road! She's purring like a kitten and never fealt better.

Thank you guys so much for your help!

 

You should always replace all six, that's why Detroit offers the 2yr and 150,000mile warranty if you replace all six at the dealership.

 

I Just replaced all 6 4 months ago. I got this new injector under warranty.

 

P

Perfect! Don't forget to set your cal codes!