So, I'm almost 100% positive that I've got a bad injector but would like to hear some input to be sure.
My truck has about 180,000 miles on it w/ the original injectors. Upon starting it up there is a light knock that gets much louder under light to moderate throttle. If my rpms get up there the knock goes away. Also while accelerating, even under light throttle, there is tons of black smoke that pours out. At idle the exhaust smells of fuel so bad that it makes your eyes burn and there is a very light haze. My oil level doesn't seem to have changed at all.

Please let me know what you think.

Thank you.

 

i am no expert at all but just trying to help. From what i have read and learned on this forum, white smoke is a sign of a bad injector not black smoke.

 

Well, the smoke/haze at idle is white but when taking off it is black.

 

Did u try taking off all ur programmers and see what it does? Some with more knowledge will probabley chime in.

 

It does sound like you have an injector that is over fueling. I would not drive it, it could have a cracked injector tip which in turn could blow off and wipe out the engine. Any rough idle, missing etc??

 

Yeah, it's just sitting until I get it fixed. Forgot to mention that it is idling rough/missing as well.

 

Start it up cold and use an infrared thermometer on the exhaust manifold to find out which injector it is. I agree with the fellow that said don't drive it.
Jim O

 

if you have an old fuel line lying around cut it and weld it, make a rail cap off tool. its the only way to eliminate a suspect bad injector from the rail. remove an injector line 1 at a time and cap the rail, start the engine and see if the smoke and knock has been eliminated. then keep the cap in your glove box. i can get you out of a broken fuel line jam or no start issue.

 

x2, look for the colder or hotter(could go either way) of the 6 header tubes

 

So, I finally got a chance to take a closer look at my truck and found that my Air Dog 150 fuel pump bought the farm. The fuse was blown so I replaced it, checked the relay and followed the power all the way back to the plug just before the pump. I also tried tapping on the pump to see if I could get it move or make a noise but got nothing. I called Air Dog and got a new one on the way (this time with the lifetime warranty).

So, given my symptoms does anyone think that my issue could entirely be the fuel pump? Is there a way for me to check my injectors while the fuel pump is dead?

Thanks for the replies up to this point

 

the problem is your fuel lift pump, I just had an 04.5 do the exact same thing. It would also run great for 3-4 mins and then would start acting like yours. Pump was heating up it seemed and then the truck would run like crap, knocking and stalling. It was very sparatic.

 

Is your idle seeming fine other than knock, low end is where it's worse and then WOT seems ok? Start by replacing the pump and I'll be shocked if you have an injector issue too. Only time I've seen them both have issues is when a buddy put gas in the tank.... that was a mess.

 

It idles a little rough in park and sounds like crap when in gear. WOT (or close to it) it was running ok but tons and tons of black smoke. I'll be happier than a pig in poop if I don't need injectors. Yet.

 

So, I installed the new Air Dog (it works) and I'm still having the same symptoms. I believe that the next step will be injectors. Any input?