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Hard starting

1458 Views 16 Replies 4 Participants Last post by  sealark, 
sealark
I have an 03 2500 HO with standard 6 speed. It has started to take 3 or 4 seconds to start when on flat level ground. However when I launch my boat on a off incline ramp (Florida) where the engine is at an angle higher than the tailgate the engine will not start for about 30 to 40 seconds of cranking. When it starts whether on level ground or at the incline the engine runs perfectly, NO misses ever at idle or high speed. I get no smoke at any time during or after starting. I tried replacing the lift pump without any change. I only have 80 K miles on the truck and bought it new. It seem like the engine is loosing it's prime. I need some advise from you pros as to what I can do to correct this problem. Could a leaking down injector or two cause this? I have worked on 671s but this computer and rail system has me stumped. :shock:
Thanks Ron,
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8secondride
a leaking injector does cause that but the angle thing doesnt make sense.
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sealark
How about that relief valve that goes back to the fuel tank on the top back side of the block with the Bango fitting? Could that be causing this type of problem? When tilted that would make fuel run out if it's defective.
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8secondride
its on the back of the head, and i wouldnt think it would. you could always take it off and check. ive seen some guys pull some nasty crud out of em because stuff just sits back there and cooks.
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8secondride
did you not have much fuel in the tank when it did this on the ramp?
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sealark
8secondride said:
did you not have much fuel in the tank when it did this on the ramp?
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I had just a little over half tank. I thought about the fuel level. but if the system was working correctly why would that matter. It surely was enough to get picked up. What really confuses me is the way it runs when it does finally kick over not one miss or hesitation at idle, running at speed limits or accelerating. And it has just recently started doing this. I also had the snap on analyzer run and had no codes. It's Monday now maybe someone has had this problem and make a suggestion. :doh:
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jkidd
what is your fuel pressure from the lift pump?
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sealark
jkidd said:
what is your fuel pressure from the lift pump?
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I don't know the pressure but the pump is new and it passed the fuel flow test. It is the pump that's mounted on the side of the block. Thanks, Please keep the suggestions coming. a couple local mechanics are also stumped because of the difference in the starting when at the angle when launching at boat ramp. I just want to figure out the reason so I can get it fixed without Parts changing like on the fuel pump mistake I made. :doh:
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sealark
:confused013:That's It no more suggestions......:banghead:
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8secondride
change the fuel filter? idk man, my only guess would be fuel delivery from tank to cp3, ie: a week LP not being to pull fuel at that angle. but you replaced it and i would think that it would be an issue not JUST at an angle if that were the case.

hook up to a nice scanner and watch the vitals while starting at an angle vs level.
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derek_661989
There's a fuel return off of the rail I assume?... I wrk on big trucks so my experience isn't in 5.9s. Anyway u let a common rail set for 2 minutes and your rail pressure drops to workable pressure. That valve that controls that (check valve). Could that be leaking the volume in the rail, on the grade?


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sealark
derek_661989 said:
There's a fuel return off of the rail I assume?... I wrk on big trucks so my experience isn't in 5.9s. Anyway u let a common rail set for 2 minutes and your rail pressure drops to workable pressure. That valve that controls that (check valve). Could that be leaking the volume in the rail, on the grade?


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Great suggestion NOW where is this valve or process located? I am sure it's survivable. can it be replaced? Please someone with 5.9 knowledge help me get my truck fixed so I can go fishing. The next thing we were going to do is put a check valve into the suction and return line. Don't want to do that if there is a correct way.
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sealark
Is the valve that allows the rail to bleed the solenoid valve located on the top of the left end of the rail? And does this valve also control the max pressure that is in the rail system or is the max pressure controlled by the Injectors high pressure pump separately. I think my problem is in the part that allows the system to bleed off when shut down. Thanks for any advise.
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sealark
After making several phone calls to several dealers repair shops and getting nothing but major repair suggestions$$$$. I finally called an old friend that had been a cummins mechanic and had nothing to gain from it monetarily told me to check and replace the at this time 11 year old short piece of rubber hose that comes off of the return line on top of the engine that runs down to the filter because it gets brittle and permeated with diesel fuel and will allow air into the system and then when at an angle it will allow fuel to run out of the system more than normal and cause the problem. I will know for sure Monday when I go get the line replaced and see if that does it. I will repost then with results.
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sealark
OK here's the problem fixed. I finally found out how the HP system works. The rail system doesn't maintain pressure after the engine is shut down only the injectors hold the required starting pressure. In 2003 the injectors were manufactured with a steel check valve and after time would leak down after shut down. In order for the computer to tell the injectors to fire there had to be pressure in the injectors. In 2004 there was an upgrade to the injectors (Not a recall) where the steel balls were changed to stainless balls. What I did was purchased 6 new OEM not rebuilt injectors $$$$$$$$$ 2200. and replaced all 6. Now the truck is running perfect. And starting as soon as i hit the switch. Man that # 5 and 6 is a Mother to get at and make sure the pushrods are in the lifter before reinstalling and torquing the rocker arms. Hope this helps someone understand the system. No one seem to know that the pressure in the rail system drops to atmospheric as soon as the engine is shut off. think about it It has to no pump could restart with that much head pressure.
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8secondride
Thanks for the update and the added info! Any idea why it would start on level ground and not on an incline/decline?
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sealark
8secondride said:
Thanks for the update and the added info! Any idea why it would start on level ground and not on an incline/decline?
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Only a guess that the leaking injectors were the last one or ones and more fluid was allowed to leak out because of the front being higher than the back. It's been starting and running like new since the replacement. And pensacola has such a bad reputation for injector rebuild is why I went with the NEW oem ones. the cost was ridiculous but I guess after 11 years of use it's worth it. If Dodge had any balls they would have issued a recall for the old steel check balls in the 2003s that they changed in 2004. At least thats what I heard so don't know if it's fact or not. I got my truck back. :confused013:
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