Quick question, if my fuel rail pressure shows around 6000 psi when cranking my LBZ, that means there should be enough fuel, going to the injectors to start it right? - thanks
Fuel rail pressure
- Thread starter BM06lbz
- Start date
Yeasir
Sent from my SM-G990U2 using Tapatalk
Sent from my SM-G990U2 using Tapatalk
Ok thanks for the replies , yeah, I’m just having problems with my truck starting idling really rough and blowing smoke, so I was just trying to rule out the possibility of not getting fuel to the system
Kind of white, and then, if you crank for a while, it will turn gray
It’s kind of a long story how it all happened and I posted it all up on the Duramaxforum It seems like it could be injectors, but it seems like injectors don’t usually go out all that one time bad enough to wear, the truck hardly starts.
So I did cranking the engine with the injector pigtails disconnected( hence why I took my glow plugs out) but I couldn’t really see noticeable fuel coming out of the holes . There was like a white air/mist? coming out , but when you had hold a paper towel up to the whole, it wouldn’t really get wet like fuel. One thing I haven’t done is a compression test but I have tested for blow by and there isn’t really any. Also, I can’t balance the injectors because my truck don’t stay running long enough. I had my autel hooked up to it last night and I’m getting plenty fuel pressure when I’m cranking , also, I can see MM3 as well, but just curious what the specs are on that
My calculated fuel rate in mm3’s is in the 50s when I’m cranking
Then plug back in the injectors and run the test again and see if you get fuel.
Normal cranking mm3 command
I’m not sure that my scanner has cranking MM3 command, but yeah I plugged the injectors in and cranked it and it does seem like injectors five and seven and injector six are possibly stuck. So now I’m working on pulling those out and I’ll probably get those tested.
One injected out seven to go, not sure what dirty injectors are supposed to look like, but that looks dirty to me
Well LDS called today and it sounds like injector 3,4,8 are completely shot and the rest of the have probably normal wear. So that means I’ll probably get some 30 over new Bosch injectors. Also beings that there was metal shavings in the fuel filter I may just end up replacing my fuel pump as well and flushing everything completely out. and hopefully that fixes the problem, although it is kind of weird that three injectors can completely go at once.
Or maybe there is different suggestions I should try?
Or maybe there is different suggestions I should try?
So I’m trying to decide between buying stock injectors versus 30 overs, my goal for horsepower is probably between 450 and 550 and that’s if I get a built tranny. I read on the forums you can use stock injectors up to over 500 but then when I called LDS, he said that I should get like 45 overs to run over 500. Then I ended up calling Kennedy diesel to ask about some tuning and to put a mildly he was not very happy that I was thinking about getting 30 overs. He said just get stock and you can easy run up to 600 with them. So that’s kind of why I’m asking.
Highly dependent on the turbo you're running and how much timing you're willing to run. 500 on stock turbo and injectors is not the best combo. Lots of timing and fuel makes it run smoky and turbo at it's max
Larger injectors lowers the timing and PW requirements to ease the pressure on the pistons and rods. Much better for the health of the engine. In my opinion, 450 is the maximum stock turbo and injectors should be tuned to do. Above that you should look at upgrades
So far, I’m running a stock turbo and probably will until it gives out. i’ll probably just go with the 30 overs then in the long run I think it will be best. Also, they’re cheaper than the stock ones currently. The biggest thing I’m running into is finding guys for tuning. I know guys who will do it, but I’m not quite sure where they get their tunes from, which would be nice to know. The ideal tune I want would have minimal horsepower, would work great with 30 overs, and also would have a special feature in it that would stop exhaust gas from leaking into my engine. Also, I guess I’m not completely sure how much tuning you need for 30 overs or if you can just put a normal 40 horse tune on and call it good. just some of the questions I’m having.