LLY: All 8 injectors bad

[LBZ]

If they put 48volts to the injector and it opened, and at 350bar nothing would come out, then you may have a bad injector(s). I don't think pressure is really that relevant to check for operation as all the injector does is control the flow, not make pressure. If you want to check a spray pattern then yes, you will need high pressure.

Also I know why there is no water in your farm fuel tank-it all ran out the bottom and into your truck!!

 

[DAVe3283]

Sorry this happened to your truck. I am with Ben and paint94979, get your injectors to a different shop. It really sounds like they don't know how to test common rail injectors. Are you sure they even put the right voltage to them? If they only used 12V, they should make a noise, but probably wouldn't open enough to flow fuel. They need to be tested at operating voltage. The 35 MPa (350 Bar) they used should be enough pressure to test them at, since the trucks idle at ~35 MPa.

Also I know why there is no water in your farm fuel tank-it all ran out the bottom and into your truck!!

lol! It doesn't hurt to make sure your farm tank is set up right, you can avoid water most of the time.

We have our farm tanks tilted so the outlet is not the lowest point, we drain any water regularly (drain is at the lowest point, and we usually don't get any water), and we run a water separator and a filter on the outlet of the tank. Even just tilting the tank a few degrees and draining the low point regularly will get 95% of the water out of the fuel.

 

[madmatt]

and they'll run at a lower pressure then 35Mpa.

 

[blackdirtymax]

i bet those injectors are fine , you need to have some second and third opinions:thumb:

 

[bmos37]

I WOULD GET ONLINE TO A FEW JUNK YARDS & PURCHASE 8 INJECTORS WITH WARRENTY & BE DONE WITH IT. i JUST SCREWED UP MY INJECTORS & THIS SEEMED TO BE THE FASTEST SOLUTION TO GET MY TRUCK UP & GOING & IT IS NOW RUNNING FINE. & MY TOTAL COST FOR MY SCREW UP WAS 740.00 SO FORGET ALL THOSE SHOPS & GET YOUR TRCK GOING. JUST MY 2 CENTS...

 

[brokentothemaxdiesel]

Man thanks everybody for the help and suggestions... Turns out that the injectors really were bad... I had them checked out at another shop. And before you all start thinking I am talking about mom and pop old school little diesel injection shops that are doing it wrong, I am not. These are big shops that do BIG business. They know what they are doing, and they are VERY well respected places around here. All 8 were bad, a couple would dribble a little, and with all 8 injectors the solenoid was working, just something inside the injector was messed up. They think it was water. They have seen a few sets like this.

So I put in the 2800 bucks worth of new ones earlier this evening along with a new CP3 injector pump, and tomorrow after work I will have it all reassembled and hopefully find out if it runs!!! My wallet $3,700 dollars lighter haha. I had called a couple local junk yards for shits and giggles after I paid for the new injectors, and one wanted 250 each per used injector, another wanted $200 each.. OH and does anybody know of a thread on here somewhere with lots of pictures of an LLY disassembly??? I have a ton of extra little bolts and brackets that I can't remember where they went... Also, some of the wiring harness routing around the intake horn and etc etc I kinda winged... Some pictures would really help me finish up.

 

[Jared Duramax]

Did you drain your tank out and vacuum it clean and flush out all the lines?

 

[whitetrash21]

x2. If it was in the injectors, you know its gonna be all over the rest of the fuel system.

 

[TheBac]

Yep..must get that fuel out of the system before restart.

 

[brokentothemaxdiesel]

Did you drain your tank out and vacuum it clean and flush out all the lines?

Yup I got it all cleaned out.. Pulled the bed off and did that the other day and Wiped the tank clean with towels after I sucked it all out with a shop vac. Then I used the shop vac to pull clean diesel through the lines from the engine bay back to the lines that go into the fuel tank module. Anybody got any pictures of the way the two main big harness connectors are supposed to look when bolted to that bracket?? I am just having a hard time remembering where all these crazy brackets go!

 

[brokentothemaxdiesel]

Alright, put it all back together, and it won't start.... I put it together correctly, that isn't the issue... Any ideas? I swear, I don't know how you all mess with these engines, they are the most complicated things!!! Give me a 12 valve cummins ANY day of the weak I could have rebuilt one 3 times for what this thing has cost me so far, and it still wont run. WTF.

 

[brokentothemaxdiesel]

Alright guys, I am about to my breaking point with this truck. I have officially rolled it out of my shop

Is there any interest in a good parts truck?? How much would it be worth you all think? Here i took some pictures of it. It has Brand new injectors and a new CP3!!!! New tires too!!! Tranny good, changed spin on every 10k, and fluid every 25k. Front and rear diff have had synthetic in them since 24k. Transfer case has had the pump rub fixed with the mechant auto kit. If I cant get some money out of it, I am going to shade tree engineer a 12 valve cummins into it.

 

[KEVINL]

Any codes while cranking did you prime the $hit out of the fuel system



When I did my injectors I didn't have one of the bale conectors completely closed and it wouldn't fire

you need to get a hold of a tech 2 or efi Live to see what the rail pressure is when cranking

 

[duratothemax]

stop screwing around throwing parts at it. I was going to say see if you can find someone locally who knows what they are doing with duramax's, but I rememberd how you said you had "40 years experience working on engines", so nvmind, im not sure why you cant figure it out?

sarcasm aside, get a scan tool. Not a code reader. An actual scan tool like a Tech 2. THAT is the ONLY way you are going to be able to fix this.

If you think working on the dmax as-is is impossible, what makes you think "shade-tree'ing" a 12 valve cummins in is going to be easy, considering all the computers/integration in these trucks???????? Sure you can "shade-tree" a 12-valve in hook up the two wires or whatever a 12-valve needs and make it run..... But you arent going to have any gauges, AC, ABS, transmission, 4wd, etc............ If you want to keep all of your gauges, AC, 4wd etc working with a 12-valve swap you're going to have to do a shit-ton of re-wiring/custom harness making, splicing, fabricating, etc. Fixing the problem you have now isnt even in the same universe of complication compared to doing a "proper" 12-valve swap into one of these trucks and keeping all of the factory stuff working.......

ben

 

[duratothemax]

is it smoking at all when you crank it? Does it crank normally/smoothly? Or does it sound rough when cranking like its hydrolocking.

you probably arent building rail pressure for some reason. The duramax isnt even going to try to come anywhere close to firing unless the pressure is above 1,500psi. With a new CP3 and all new injectors there is NO REASON it should not be building rail pressure.

Either the fuel lines are still blocked up or you have an air leak somewhere. Or you didnt tighten something etc........... The CP3 is a high pressure low volume pump. Even with a slight dribble leak somewhere it wont build pressure.

 

[Cougar281]

If everything on top of the engine (rails, injectors, lines, CP3, etc) where removed & cleaned and are now empty, it will take a LOT of cranking to get everything filled up and build sufficient pressure. When I swapped the LBZ into my truck, everything on top of the motor had been removed and was empty. It took at least 90 seconds (not sustained) of cranking before it filled the rails up and built enough pressure to start.

 

[LBZ]

I'm willing to bet you haven't primed the fuel system enough. When you do what you did to it, it takes A LONG TIME to get fuel throughout the whole system without a lift pump. You need to either put in a lift pump or pump like you have never pumped before at the fuel filter housing -until you get fuel out of the bleed screw. Then close the bleeder and pump the hell outta it some more. Binder dundiss before so I know!!

 

[dmaxfireman]

buy me a plane ticket and and give me access to a shop and we will work out a deal for getting it running...

 

[madmatt]

X2 on getting a real scanner! Gotta know what rail pressure is while cranking to help any more but my bet is on just simply not primed. They'll wear you the eff out priming them after you've had the system dry like that.

 

[smoke660]

opcorn: