Need Help Fast....Bad Injector???

[KWIKKURT]

My truck has developed what I can best describe as a slight miss.



I have noticed a change in the sound and or feel of the engine. It has run perfect for 59,000 miles. I came up to the USA today and it is gradually getting worse. I decided to stop as I don't want it to get worse!



What ways are there for checking for what is causing the miss?? I need any help I can get as tomorrow is the 4th and everything will be closed (Local Cummins or Dodge). I have injectors at home in Mexico but do not want to drive it if it is something more serious and need to be there ASAP.



Thx in advance!!! Kurt

 

[Vaughn MacKenzie]

Kurt, sorry to hear about your drivability symptoms. If it is a steady miss like just one cylinder is causing it then that's what I'd guess. . . a failing or dirty injector.



There is a way to isolate the cylinder, using the same concept as removing spark plug wires one at a time and checking RPM drop. Basically loosen, one cylinder at a time, the injection line nut that screws into the head, then tighten and go to the next cylinder. . . the problem cylinder will cause less RPM drop. But WARNING!! I'm sure you know to be careful with high injection pressures. . . don't loosen 'em while it's running or stick you face down there either unless you want to lose an eye (or die).



Anyway that is all I can think of. You might want to start with the basics and check the fuel filter & see if the lift pump is working first. Of course this kind of stuff happens on a holiday when you can't go pick up needed items!



Keep us posted and good luck.



Vaughn

 

[KWIKKURT]

Vaughn,



Thanks this is the kind of info I need! I have a lot experience as a mechanic but other than upgrades my truck has run perfect.



I have a second lift pump in parrallel with the stock I added when I saw how low the pressure would go "0" with the stock one. It is a carter like the oem. .



Any Ideas on how to check the VP44? I could listen to the lines with a stethascope? This is going to drive me nuts untill I know what's wrong!



I ran the truck completely out of fuel for the first time last week and it took me a while to restart even bleeding three injector lines and running both lift pumps. I think the stock lift pump is weak but I have the second one set to turn on when the pressure drops under 4 psi. I run fuel additive 85% of the time since the truck was new and the fuel filter was changed 3,000 miles ago.



Kurt

 

[Archive]

Kwikkurt, You might also consider adjusting the valves. Anyone who has checked their valve lash while installing injectors will tell you 100,000 plus miles before running the o'head might be a little too optimistic. Blue Chip markets a VP44 pump tester, but I am unfamiliar with how it operates. Good luck troubleshooting the problem.

 

[KWIKKURT]

Topfuel, Thanks for the idea! I have 58,000 miles all of driven on sundays



I checked my IAT this morning after reading other topics. It was pretty grimey. . Cleaned and reinstalled.



I want to add that the miss is very light and almost not there at idle. But the normal idle knock sounds alittle different.



It was most noticeable at cruise under light load. If I step on the go pedal it sounds ok but cruising it sounds and feels different. Like it has lost that crisp, clean hum. I also feel like the engine vibration is off.



I checked blowby coming out the oil fill last night when it was hot and it seems fine.



This morning when I started it the miss (at idle) is so slight that I am not sure I could notice a difference in the injectors when droping out one at a Time.



I am going to go for a drive and see if cleaning the IAT helped. . If it is not any worse I may drive home and change to my other injectors... Please keep the suggestions coming!!



Thx Kurt

 

[Turbo Thom]

Kirt:

I saw a Dodge dealer here in Georgia run a 24V out of fuel and they were worried about the lift pump. Got it started and said it didn't sound good . Remember the 24V's lift pump and the injector pump are intergral to each other. The injector can be clogged but the pressure to the injector has to be the same all the way across. Down here some VP44's have goon bad because of low fuel pressure. I would check there and be careful.

Preston

 

[Evan A. Beck]

If you have any electronic modifications, unplug 'em and try it then. If the miss is still there go to the next step...



Do the "key trick" and see if any fault codes are present.



If fuel pressure checks out OK, and the fuel filter is clean, continue on... What is your fuel pressure while cranking? At Idle? At WOT?



Try swapping out the injectors and putting your stock ones back in. If the miss is still there, it is more than likely your injection pump. We had a truck in the shop about 6 months ago with the same problem you are having. We thought it was a bad injector, so we swapped the Dr. Performance injectors out with a set of 275's. Problem was still there. Fuel pressure was good, and the filter was relatively new. So, we replaced the injection pump, and it cured the problem. Then, we put the Dr. P injectors back in, and the truck ran like a champ. It was a 2001 ETH 3500.



Good luck, and keep us posted!

 

[Shooter]

You might want to try and get a hold of cscpusher in the Phonex area. http://www.canyonstatecomponents.com

 

[KWIKKURT]

Evan, TurboTom



Thanks for the responses: This is a tough one!



On the way home at times it was not there(miss)



I have unhooked the PE comp and no change. I am going to check valves I think maybe I am just a touch paraonid after My Turbo (HX40) blew up last week.



Maybe this is all it is:



1. With the Stock turbo back in truck the Exhaust Stacks are quieter so I hear the engine noise more.



2"I am missing a exhaust manifold bolt". . (Thx HVAC) That could be the slight extra loud knock.



3. Add in the new BFG's that can't seem to be balanced so they don't shake at aleast once in a while.



It ran almost perfect today so I am really confused... Maybe it is just my imagination and the combination of changes... .



I will keep you all informed... . I plan to check valve settings, swap inj's and replace manifold bolt and if it's not perfect wait and put Bombed turbo back in. Then if I still think it's not ok have the VP44 checked.



Thx Kurt

 

[HVAC]

Kwik,



"2)I am missing a exhaust manifold bolt". . (Thx HVAC) That could be the slight extra loud knock. "



I'm glad if I have been of any help

 

[Alan Reagan]

Kwikkurt, Sometimes an injector will stick (because of carbon) and cause a miss. Usually you'll get smoke with a stuck injector. Don't know if you use additives but you may want to run some through there.

 

[KWIKKURT]

Alan, Thanks for the reply... I normally run additive about 85% of the time... The injectors have about 8 to 10,000 miles on them.



I do buy fuel all over the place... . (even here in Mex. ) But try to stick to the popular (Trucker) and high volume stations. I would be curious to get some of the diesel from here tested to check the levels of Sulfur ... Etc. and the Cetane readings.



I have run one tank through since tuesday night with additive and have a second in the truck now.



I have heard about filling the Filter with additives and then start for a short period then let it sit overnight... . Any comments from anyone????



Currently the miss seems to come and go... ... It is just strong enough for me to notice that it sounds different then other times I can't hear it at all..... It may turn out to be a loose stack mount or something simple. Or worst case is that the VP44 is acting up. . but I don't think so. .