Engine/Transmission (1998.5 - 2002) Injector Tube Replacement

[Ncostello]

I've tried all the good suggestions so far but none have helped. I'm going to replace the injector tubes in my truck. I figured at $11 each, its worth a try (slight idle miss is the topic). I dont have any leaks after my injector install but one did and I had to tighten it more. It also looked like the previous owner had to bleed air or something as dust collected where the diesel fuel ran out. I'm going to go ahead any buy the injector puller and the tube puller tool. I think its worth the small investment over time. I've spent alot more on tools that are alot more useless. I imagine I'll be puttin in some bigger ones some day anyway. And, I'll then have 200% more Cummins tools than the local Dodge dealer... hehe. Makes me feel better.



When I take out the old ones, I'm going to have to completely remove the HP fuel lines. I think I can loosen them from the pump and the head, remove the hold downs and remove them as a group with some of the clamps holding the assembly together. Is this a correct assumption? Or do some lines need taken out seperately?



Also, do I need to loosen the injector hold downs to get the new tubes lined up with the injectors properly... ya know, snug the tubes, then the injectors, then the tubes again until I approach the torque values so that they line up real good. If I should, thats OK cause I want to check the hold down torques again. I also want to use an extension wrench on the torque wrench to get to the other hold down bolts. I think I should check their torque. I'll use the calculation to reduce torque based upon the wrench length.



I just have a sneaky feeling the tubes are bad. If it comes out they are not, I'm gonna start checking the EGT's at each cyl with a heat gun. Maybe its a bad sealing valve or something causing the idle miss.



Its war now and I will root out the enemy one way or another.

 

[MikeR]

To be honest, you're throwing your money into the wind. Why didn't you take your truck to the real cummins techs at Cummins in the first place. They have a tester that bypasses the truck electronics, and there is also a tester that shuts down individual cylinders so you know which one is giving the problem.



I've been reading your treads on your idle miss and I've been thinking bad injection pump all along. I just hate to see you wasting money on parts you don't need (or are obvious to me).



-Mike

 

[Neal Cassady]

I don't think you will need to remove the high pressure lines to remove the connector tubes. You should be able to just remove the little blue line clamps where necessary, move the line enough to pull the connector tube out. Make sure you don't move the high pressure line enough to tweak it. If you do you could have a hard time getting the high pressure line to mate squarely with the connector tube and the fitting in the head.



If you are going to use the connector tube removal tool, you will probably have to remove the high pressure line completely to make room for the tool.



I would loosen the injector hold downs before removing the connector tubes.



When you remove the hold down and connector tube you might as well pull the injector so you can check all the metal to metal sealing surfaces. Also check the tubes for any debris.



I would pick up 6 new copper sealing washers for the injectors before pulling them for inspection.



Good Luck,

Neal

 

[Vaughn MacKenzie]

Ncostello, if you haven't bought injector tubes yet, but still want a set, I have a set I will sell you for a lot cheaper.



Vaughn

 

[Posm]

Neil

I also have a slight miss and have tried seveal things. The IAT has helped at times, as well as running a strong dose of injector cleaner through a couple of tanks.

I just had the crank position sensor replaced when it completly failed. My idle is still not solid when warm. I knew I had a slight fuel leak and took it into my dealer. They torqued down on the tubes and got the leak to stop. I then had them hook it up to their computer. If your dealer uses the DC plug inside, under the dash they will not be able to tell much. My dealer hooked up a laptop to a plug under the hood. It is the same plug my Edge hooks up to. He then put on a diagnostic program that took about 10 minutes to check each cylinder and then reported they were within a couple of % of each other. He could also check all the sensors in real time and see if they aggree with each other.



He also told me total hours, 3290, total miles, 146800, and total gallons burned 9127 since new. He also knew I had gone 94 as a top speed.



Pay the hour of labor and ease your mind.



Bryan

 

[Ncostello]

I'll probably go ahead and remove the lines completely. I could think of worse things to have to do. I dont even want to chance tweaking the lines.



I am almost positive the Cummins Service Center I took it to used INSIGHT or something like that. They didn't use the plug inside the truck. It only took about 15 minutes but I didn't get all that other info. Not saying they didn't have it, they just didn't tell me. Im gonna call them back and talk about it. Maybe get another test. I want to be there this time, and I want to see it happen. I want to hear the engine myself since I'm gonna be the one turning the wrenches.



Hey, is there any "civilian" version of that program. I have some computers here at work with nothing for them to do. I'd stick one in my garage to play around with if I could get the program. Its probably a $20000 setup.

 

[Steve St.Laurent]

You can remove the lines in bundles like you said - it's the easiest way to do it. They come off in two sets of three lines. Just unbolt the brackets where they go into the intake manifold, loosen the bolts completely at back of the injection pump and at the head and then take them off as 2 sets. It will take a while get the truck reprimed and you will definately have to leave the lines loose at the head to bleed the fuel lines.

 

[Vaughn MacKenzie]

I've replaced injectors and tubes a number of times. Too much work IMO to remove the lines completely. Plus it takes MUCH longer to prime and fire up afterwards. Another disadvantage is you increase the risk of getting contaminants into your lines if you take them all the way out.



With all the blue hold-downs removed the lines are flexible enough you can gently pull them to the side enough to clear the tube as you pull it out.



I always use a small flat blade scredriver to pop them out, works good.



Vaughn