Just did 2 injectors ran2 days now skipping

[earnies2]

In the Grove crane ware i used to work developed an injector knock i couldn't determine witch cylinder it was 1 or 2 so i replaced the front 2 I ran the overhead (thanks Rawze) and it ran great for 2 days then started skipping.....i got it back to the shop and had the local shop come down and put a computer on it it showed a bad EGR valve and 2 dead cylinders #4 and #6 thank god it wasent #1 or#2... so i am now back into the engine to replace the 4 i didn't replace in the beginning along with a EGR valve and a rocker box gasket I have never done Injectors before and i am in uncharted waters...so far so good its all apart...now to clean everything up and install new parts i also got an injection harness to can anyone tell me the necessary torque specs and any tips to assembly i would appreciate it thanks

[Rex012]

When I did 2 I just did all 6 kinda figured if 2 are failing the other will or are starting too.

[earnies2]

well i got everything all cleaned up and started assembling i went to Cummings and bought a bunch of seals, o rings,new bolts for the EGR valve,and some hoses and gaskets to the tune of $400 and i asked if i could get the torque specs of the rocker box,the rocker arm shafts,the jake adapter and the injector hold downs and their reply was they can not give me those specs because of liability but they would gladly send a tech out to torque down those items.........do they SUCK or what i had a good mind to give them all the parts i just bought and tell them what to do with them.....what is this world coming to

[Pigpen 2868]

That sounds like a response from one of the counters in Dedham Mass.

[preacherboy24]

Try Quickserve for the specs. It could be the bad injectors were letting combustion gases into the fuel rail and took out the other two injectors. You can get Quickserve for your phone. Just put in the engine serial number and you should be able to get the info you need right off your phone..... but if that doesnt work you can go online and get it off the website.

[Hammerhead]

(12-30-2016 )preacherboy24 Wrote:  Try Quickserve for the specs. It could be the bad injectors were letting combustion gases into the fuel rail and took out the other two injectors. You can get Quickserve for your phone. Just put in the engine serial number and you should be able to get the info you need right off your phone..... but if that doesnt work you can go online and get it off the website.

I'd do this. I agree with Rawze, I'm not a fan of torque plus angle method for the rocker shaft assemblies. The thread bores are too short and the bolts are not stretch type.
Shortcut: 70 ft/lbs is what I torque my rocker shaft bolts to...it's in the video. Credit where it's due, thanks Rawze. I've tried torque plus angle, and it feels like either the bolt or the head is about to break, scared the crap out of me!
Everyone needs to set up a Quickserve account and enter their ESN. Every single step by step is right there to dismantle your engine so no two parts are connected, and then put it back together again. Cummins does a pisspoor job of promoting this resource.
If you have:
- A Quickserve account
- An Inline connector with Insite
- A decent tool box
- A membership here for this resource
There is no need for a mechanic again! With those four simple things, the curtain has been pulled back and the shackles have been removed! You are free!

Unless I'm doing something wrong, the Quickserve mobile app only shows parts not procedures. I use the online version to access procedures.

[Rawze]

(12-30-2016 )Hammerhead Wrote:  

(12-30-2016 )preacherboy24 Wrote:  Try Quickserve for the specs. It could be the bad injectors were letting combustion gases into the fuel rail and took out the other two injectors. You can get Quickserve for your phone. Just put in the engine serial number and you should be able to get the info you need right off your phone..... but if that doesnt work you can go online and get it off the website.

...

Shortcut: 70 ft/lbs is what I torque my rocker shaft bolts to...it's in the video. Credit where it's due, thanks Rawze. I've tried torque plus angle, and it feels like either the bolt or the head is about to break, scared the crap out of me!
...

Actually, since that video, we have found that 70 ft-lbs is a bit on the low side for them, but tight enough not to come loose. The average is roughly more like 105 - 115 ft lbs using the other method. 105+ I think is too high on an older head that may have been disassembled a time or 2. - I typically do the bolts at 95 ft lbs these days. that is still very tight considering the bolt and thread size.

I completely agree that they are not "stretchy" bolts and that the head is cast, etc. - A set torque spec is still preferred if you ask me.

[Hammerhead]

(12-31-2016 )Rawze Wrote:  Actually, since that video, we have found that 70 ft-lbs is a bit on the low side for them, but tight enough not to come loose. The average is roughly more like 105 - 115 ft lbs using the other method. 105+ I think is too high on an older head that may have been disassembled a time or 2. - I typically do the bolts at 95 ft lbs these days. that is still very tight considering the bolt and thread size.

I completely agree that they are not "stretchy" bolts and that the head is cast, etc. - A set torque spec is still preferred if you ask me.

Thanks for the update, I will update my procedure printout!
I couldn't agree more on a set torque spec. There are items where torque plus angle is necessary, but Cummins seems to really overuse it IMHO.
I could feel that 70 was a fair amount less than the procedure, but I've checked mine a couple of times and they haven't been loose, so I've left well enough alone. I'm planning on replacing a couple injectors shortly, so I'll put this new info to use!

[Rawze]

(12-31-2016 )Hammerhead Wrote:  Thanks for the update, I will update my procedure printout!
I couldn't agree more on a set torque spec. There are items where torque plus angle is necessary, but Cummins seems to really overuse it IMHO.
I could feel that 70 was a fair amount less than the procedure, but I've checked mine a couple of times and they haven't been loose, so I've left well enough alone. I'm planning on replacing a couple injectors shortly, so I'll put this new info to use!

Just remember that you want to wick out any oil from the holes before installing the bolts. I have seen that mistake before, and the results are sometimes not pretty.