So here's a little background on this truck. 2004.5 One ton dually flatbed, 5.9 HO, automatic. I purchased it with 125k on it and it's just turned over 200k. It's usually hooked up to a GN trailer hauling my CTL, total about 15,000 lbs. When I first got it, I used Power Service at the first fill-up like I always have in my PowerStroke. The truck went into limp mode and continued like that until I got it diluted enough with new fuel...then it started running fine. I haven't used PS since. Last summer the lift pump went out, so I had that replaced. A couple of months ago the truck got harder and harder to start, finally taking at least a one hour cool down to get going again. When it finally does start, it runs fine. Plenty of power and no smoke unless it idles for a long time, but the smoke goes away in a hundred feet or so. I read that it could either be a stuck injector, or the high pressure fuel pump causing the no-start. Either could slow the engine to build rail pressure when hot. Some comments pointed to the HP fuel pump diaphragm being damaged from a weak lift pump since it has to work harder. I suppose this could be true. I don't know how long the lift pump was failing before it finally went out. There was a suggestion to run 2-stroke marine oil in the fuel to lube things up. Something about the low sulfur fuel and older engines. I did that for the last two tank fulls. Today, I was running to town for stuff and noticed that it didn't sound quite right at idle. Kind of like a cackle. No change in power at all. When I got home the cackle sound was gone, so I shut the truck off, went inside and then (forgetting that it's warm and won't start) jumped back in it five minutes later and it fired right up! So...it is possible that a stuck injector is now unstuck? I'm clueless on this one.
The high pressure fuel pump (CP3) on your truck does not have a diaphragm. It has a gear pump that supply's the high pressure pistons. The duramax powered trucks have the identical type of high-pressure pump, and do not have any sort of lift pump at all, so there's no chance of your lift pump failing and taking out your high-pressure pump. As for your problem, how often do you replace fuel filters and what type of fuel filters do you normally use? There is a possibility of sticking an injector, but it is very uncommon and it usually results in either a hydro-locked engine from fuel flooding the cylinder, or a torched piston from excess fuel. I would eliminate injector from the issue as well. *You could however have a slow solenoid on top of the injector that causes a delayed fuel injection event, producing a different engine sound and a little bit different power output. I would first start by checking your valve cover gasket wiring harness connections. Your truck is a 04.5, which means it has 3 injector harness connections on the driver side of the valve cover. This harness sends a high voltage signal from the ECM telling the injectors when to fire and how many times. Make sure nothing is corroding these or causing one to be loose. I firmly believe that you have an electrical issue.
Good info and thanks for responding. I've tried to get info in the diesel truck sites before, but those guys make it sound like you shouldn't even drive a diesel unless you have pods, mods and everything else. I'm just not into that...I need the trucks for work. That's why I posted here since I figured I'd get straight answers. The truck is due for a new fuel filter, so I'll pick one up tomorrow. I'll also check the wiring harness connections and see if I can find anything screwy there.
I started with the diesel truck scene when I was 17, I have since grown up. Lol.
I have encountered this issue more than once only in industrial applications. Faulty injectors were the issue. There was no problem with the injector tips rather injectors leaking common pressure to return. The engine will eventually start when fuel volume can over come the leak and build enough pressure to signal ECM to open injector solonoids. There is a return fitting banjo ed to the back of the head. Remove the banjo screw and observe leakage , there should be almost no leakage from head port while cranking. If it is coming out good you have an injector leaking, but not into the combustion chamber. The method I use to determine which injector is leaking is to acquire a spare injection line cut and weld the end to use as a plug. Plug the line to each injector one at a time. When the flow at rear of head stops the problem injector has been identified.
That is the old school way to do it, very correct don't get me wrong, but extremely time consuming. Just plug into a powerful scanner and preform a cylinder contribution test and injector leak down and that will verify if the vehicle has a failing injector.
Serious question... How would a diagnostic program determine which injector leaks down in a common rail ? Old school maybe, but I can't afford programming for every brand engine I encounter. I would already have the new injector installed by the time a so called technician determines that the high dollar software won't help tell him what to do this time. Diagnostic software is overrated and often not necessary for diagnosis. IMO of course.
You would check leak down via the cylinder contribution test. Detroit Diesel Diagnostic Link can specify which injector is leaking. Cool stuff.
I believe you, I just can't wrap my head around it. The reason is; A single leaking injector would drop the pressure across the entire rail, so each injector would be experiencing the same pressure input not just the one leaking. Hope I have not got off track of this thread discussing common rail theory of operation. However a injector leaking into the combustion chamber would show up on contribution test or by observing piston deceleration ( perDel).
Have not Sean it on a contribution test but Takes 10 minutes to check return fuel. I have had the same problem on a few dozers ran fine but shut off and try to restart and would not. Let cool a bit and start right up.
So a little update. The next day the cackle was back after driving a few minutes, but disappeared by the time I got to the job. I did a bit of jiggling at the connections CA mentioned and the noise hasn't returned. Funny thing is...the no hot start has not happened since I first noticed the cackle.
I'm inclined to agree with those leaning toward an injector issue. The CP3 was a HUUUUGE improvement over the VP44 abortion of an injection pump. However, unfortunately, it also brought along with it common rail injection. These injectors are notorious for having issues and are extremely sensitive to any form of fuel contamination. It's crucial to when possible get your fuel from a station that has a lot of traffic so you know you're getting fresh fuel and staying on top of fuel filter changes. I hope you get it figured out soon and for your sake hope you don't have to change all the injectors. These CR units are not cheap!
Well it's been two months to the date since the last time I posted. Since I took the connections apart, blew them out and reconnected them the problem has disappeared. It starts great and runs like a top.
Good deal, thanks for the update.