I have an 04 Dodge with the 5.9/ 305hp/555ft lbs engine. This engine has run very well for 103k miles. It now has a steady misfire in one or more cylinders. I checked codes and got none, so the computer and all systems are functioning properly. I brought it to a commercial diesel shop and they confirmed no codes on the computer, checked fuel pump, and common rail pressure and all were within tolerance. Then using an infared theremometer detected most cylinders were running at 140-180 degrees and #5 was at 250 degrees. The mechanic said I had 5 injectors not firing properly. A while later the mechanic called back and said he talked to a 5.9 expert and the bad cylinder was the one that was the hottest or 250 degrees. My question is do I have 5 bad injectors or just one? My experience with engines says 5, the hot one is firing properly and the others are weak. What do you think?

 

I would look at a little more before I laid some cash out for injectors. I would start with the crank position sensor and the tine ring with the little notches in it. make sure one or more tabls aint bent, it's not covered in crud, etc.

 

It wouldn't really matter to me if it was 1 injector or 5, because I'd be buying a set of 6.

 

#5 could be firing too much fuel, which could be mistaken for a missfire. Another pausiblility could be the cylinder that fires before #5, which is #1, could be firing weeker and #5 is working harder for it. You would think the shop could have cancelled cylinders out to find the problem. Just some of my experiences with the bigger engines.

 

I would go after #5 because its 100 degrees hotter than the rest. If #1 was weak it would be colder with the heat gun. That is what I have found with my experiences with common rails.

 

Thanx for all the reply's. Today I told the mechanic to pull all the injectors and test them. (They use Pensacola Injector) Also to do a compression test on all cylinders to make sure I didn't burn a hole in a piston or burnt a valve. Good thought about the cps though, I will ask the mechanic about it as well. If I need injectors what is a good source for new/or rebuilt stockers? Is it worth going bigger? I tow a 5ver (abt. 13.5k lbs.) and do some hot-shot hauling with this truck and are always looking for better fuel mileage. I am not sure these mechanics are real familiar with this engine from some of the responses they have given me. Has anyone on this forum changed injectors on the CR or can you tell me where can I find detailed info on doing it myself. I have changed injectors on 6BT and 6BTA marine engines and you could do these in about and hour, but from what I have read here there are about 50 steps to disassembly.

 

I had industrial injection rebuild mine. DonM Is popular on here. Can't tell you if one is better thant he other. I believe Industrial has a quicker turn around time but not for sure. I had them put on 60hp tips. I tow a 5ver and unless I have the TST turned up, EGT are right foot managable. I could peg 1300 with the stock tips and these don't rise any faster. Power is a little better on the low end. No smoke unless I want it to. As for fuel mileage not sure if the tips or rebuild I regained back to 20-21 empty and 12 towning the 5er. Before the rebuilds I was about 15 empty and 10 towing. I didn't replace them my self but the labor charge to take them out and put them back in was 3 hours. My understanding of the procedure is ensure truck has sit a while for pressure to bleed off. Remove injector line, then cross over tubes. Then to valve cover removal. Then remove the solinoid connections. Two small nuts. Then remove the retainer. I think on some you have to remove intake rocker arm but not all. There is a pulling tool but I have heard you can do it by hand if careful.
Those directors are more of an overview not actual fact from actual experience. I know it has been posted the exact procedure but I can't find it.