No power, no codes, no more money, no more patience, and almost no more duramax!

[Stevenmc89]

Someone has to know what this could be. I've posted a couple threads here without any definate answers and I'm to the point of frustration that I'm actually looking for a king ranch! The truck has lost power and I have to keep the predator on the 120hp tune just to have power to drive it to work. When the truck was running normal it had plenty of power, would smoke my 37's, and blew black smoke on the 120 and 95 tune now it don't blow smoke but once every now and then which makes me think lack of fuel, won't spin the tires even on wet pavement just chirps them, the exhaust has gotten loud as hell like its pulling a load and straining, and now has to down shift on hills that were never a problem. When it first started I changed the fuel filter and nothing changed then starting seeing a couple sketchy balance rates so i had the local dealer replace all 8 injectors last week and still nothing! The truck starts up and idles perfect but I noticed the primer bulb is soft every time I check it and have to pump it 10-15 times to get hard and it looks like maybe fuel is around the primer bulb leaking from the 2 seals inside of it. Also the lines coming off the filter head look real weathered and dry rotted so I've ordered a fuel filter head re build kit , nicktane adapter with Donaldson filters, and I'm getting new lines from gm which should all be here by Thursday. I bought the truck from my best friend who replaced the cp3 in may which the same dealership done and most last 200,000 miles so i doubt its the problem, and I also knew the owner before him and neither dogged the truck and it only pulled a bobcat and a smaller John Deere tractor maybe 20 times and a trailer loaded with watermelons during the summer when my friend had it so its had a pretty easy 250,500 miles. So the symptoms are: low on power, horrible fuel mileage, won't blow black smoke like it did for the 3 years I've been around the truck, it has no codes except for my bad glow plugs, and the exhaust has gotten loud as hell like its under a bad load. What's been replaced/done in order: cp3 in may, new fuel filter 3 weeks ago, cleaned the air filter 3 weeks ago, cleaned mass air flow and map sensor 2 weeks ago, oil change, coolant flush, and 8 Bosch reman injectors installed by dealer 4 days ago.

So could it be sucking air in the housing or lines causing it to starve for fuel but not causing starting/idling issues like maybe a small crack or hole that pulls air in under vacuum but not leaking fuel or letting enough air in to cause starting issues? Maybe a fuel pressure regulator not letting it get enough fuel? What about the pressure relief valve bleeding off pressure? Dirty filter sock? There has to be someone that has had the same issue and found the solution. I don't know anyone with a solus or tec II and being a new father with bills out the yin yang and just having to barrow money for injectors I don't have the money to pay the dealer to hook it up and tell me its fine like many have done before. I always have a problem like this with every single truck I've owned that nobody could figure out and it took up to a year to trace down or finally throw enough parts at it to finally find it. If anyone knows what this is I will send you $50 dollars threw pay pal. I've wanted this truck for years and sold my paid off Z71 and took on a truck payment to get what I thought was a good truck since none of the owners had any problems in 3 plus years except a cp3 and speed sensor and now I'm sick to my stomach knowing I sold a good truck for this hunk of crap that screws up a month after I get it and have to make payments for 2 years on top of that! Sorry for this long post but I just wanted to give every single detail so maybe I can get this thing going! Thank every one of y'all for all the help!

[TakeEm]

Well first off that leaking fuel around the filter head isn't helping you. There's a good chance you are pulling in air, but I think you have other problems. You really need a way to log the truck and it should be pretty easy to figure out. Does it still spool up?


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[TDIpowered]

Leaking fuel? Fuel filter head and lines in bad shape? Not smoking (smoke=unburnt fuel)? Sounds like your not getting fuel. If the fuel filter head rebuild doesn't work then you need a lift pump.

[Stevenmc89]

I wish I had a way to log it but all I have is my predator which will read boost, MAF, ECT, IAT, EGR, engine load, injection timing, 1-8 balance rates, desired rail pressure, fuel rate in mm3, false power take off, mph, and rpm. I don't know much about the turbo like when it builds pressure etc. I've seen the boost up to 22psi cruising at 65 pulling a hill in 5th today which I had to ease in to it pretty good. I know it's supposed to be around 30-32 iirc at wot which even with this power loss I've never had it close to wot because I'm trying to take care of her

[Stevenmc89]

Don't get me wrong i know a lift pump would help and I plan on getting one someday but it's never had a problem without one in the 3 years I've known the truck so it has to be something wrong and I just want to get the problem fixed before I add any thing I really don't need but want real bad lol

[Mpope]

I'm not a mechanic but I do like to tinker with engines. I've had similar problems with a gasser and it was a computer issue. However, I have to say that your description sounds like an engine starved of fuel. Your description of a good idle but low power at higher RPM's sounds like it is sucking in air somewhere. I believe (and hope) that your rebuild of the fuel filter housing and new lines will take care of the problem. Please let us all know as soon as you get it done. And resist the temptation to go over to the dark side (Ford). I've read some bad things about those engines having rust problems in the fuel system - besides that, they are plastic trucks.

[Stevenmc89]

Originally Posted by Mpope

I'm not a mechanic but I do like to tinker with engines. I've had similar problems with a gasser and it was a computer issue. However, I have to say that your description sounds like an engine starved of fuel. Your description of a good idle but low power at higher RPM's sounds like it is sucking in air somewhere. I believe (and hope) that your rebuild of the fuel filter housing and new lines will take care of the problem. Please let us all know as soon as you get it done. And resist the temptation to go over to the dark side (Ford). I've read some bad things about those engines having rust problems in the fuel system - besides that, they are plastic trucks.

Thanks bud I hope and pray it fixes it. I've always wanted a 2001 or 2002 ccsb duramax ever since I first saw them when they came out when I was like 13 and I finally got one and this crap happens so to say the least I'm disappointed. I looked for months and couldn't find the one I wanted then my buddy finally gave in and sold me this one. My second choice to this would be a copper colored king ranch about an 05 model because that color and them seats are the cats meow in my opinion lol. Does anyone know for sure that it can suck air under vacuum and still run like mine is? The local dealers duramax mechanic that done the work said air is lighter than fuel so it would just suck the air and not any fuel but I had one guy say his lost power and the FF head rebuild solved it?! I've always done my own work on my 5.7 and 5.3 motors without a problem but this is a whole new territory for me and for once I'm 150% stumped and have no idea what in the hell is going on with this thing! Also it seems like when its up to speed (65 or so) it don't act up as bad but it might be that it's already got the truck up to speed so its easier to keep it there since its not as much load as taking off and getting it rolling

[critchjr]

I know this is off the wall and prolly not it, but have you checked the Billows on the up pipes? I had a buddy that had a F550 with the 6.0 and it wouldn't run to get out of it's own way, didn't smoke, and idled like a champ with No codes. He had the shop I was working in pull the engine so he could do a cummins swap and we found a billow(the flexy part) on one of the up pipes blown out. I know things like this are a pain in the a$$, but keep you head up man and don't go to the umm "other" side

[Mpope]

Your mechanic is right. Fuel is more dense than air. SO, if there was a big enough hole for the suction to pull in nothing but air you would have no fuel and the engine would not start. It sounds like you have a tiny leak that is only effecting the system with there is enough suction (suction increases as the engine demands more fuel for higher RPMs). Because air is much less dense than fuel, it is even possible to have a leak small enough that air gets in but fuel does not come out.

[Stevenmc89]

I have a feeling this is gonna be another one of my mystery problems that won't get solved for a while... As far as the boost leak I've checked over intercooler tubes pretty good and looked at the common spots ie driver side tube over power steering hose and boots with detail and saw no leaks and everyone said it would blow black smoke like a skeeter truck on a duramax. If the FF head rebuild don't fix it then maybe the dealer will knock some off the price to diagnose it seeing how I just gave them 3,788.58 last week. With my luck they won't find anything wrong or they'll tell me I blew a hole in a piston or some other expensive crap