tom mapes

Hi all, first post- in a bind, hopefully some experts can give guidance. I'll start with the story, then end with any other information that might be pertinent.


Yesterday I went to fire up the truck and it just cranked...and cranked. So I waited a minute, cycled the key, listened for fuel pump, looked at gauges, all the normal, dumb, scared, holy crap my truck is dead stuff. Tried again, crank, crank, crank, nothing. Hooked up the battery charger and went inside to research.


Looked up common 5.9 problems, looked at schematics for fuel system, dug up my scanner, watched the 4 part HPCR videos, skimmed Chilton's a bit, then went out after it.



Started with the scanner, only 1 code about a fan clutch, cleared. Read that some people's trucks won't run with the P0480 code, and some do... wouldn't start with fan plugged in or not, unrelated I guess.

Started with pulling line between lift pump and CP3 and putting a piece of fuel line into a bucket- cycled key on, nice steady flow. Reconnected, tried starting again, crank, crank, crank, don't wanna give up, crank, and she fired! Although I didn't "do" anything...it sounded fine, no smoke, no knock, nothing out of the ordinary. Shut it off, restarted 10 times in a row no problem, left running for 45 minutes, watched gauges, looked for leaks, listened, all ok. I guess we'll see how she does tomorrow morning, eh?


Tomorrow morning- ie, today: NO START! Same deal, hooked up battery charger and continued researching. Learned that I needed 5k psi rail pressure to start, and realized I needed to be able to monitor that pressure. Looked into my bull dog outlook and saw fuel pressure as an option. Selected fuel pressure in the BD outlook and tried again. Approx 1500 psi cranking pressure (batteries still cranking fast). Continued reading, looking into FCA test at this point. Unplugged FCA, cranked while watching pressure, 1500 for a couple seconds then climbed quickly, started and now I have 6000 psi at idle, but it did NOT max out like the write-ups said... Hmm, weird. Reconnected FCA plug, cranked while watching rp, 1500 for a sec, started, 6k at idle, 13-15k around 1500 rpm, maybe 18k during free-rev (display only refreshes so fast). Runs, idles, revs normal, starts normal. Unplugged FCA and tried again, same results plugged in or unplugged- except I do get a little rough idle and a small intermittent knock when it's unplugged, but pressures don't change, everyone said it'd jump to 23k psi.


Does this mean FCA is or is not a problem? Could be CP3? Injector(s)? Connector tubes? My next test would be the CP3 return flow test and the injector bypass test, but I don't have the special miller 9012 banjo isolator/connector... I did however pull the PRV line and restarted engine to check for PRV passing- all ok there.


Extra info- 2003, 160k miles, ran perfectly when parked the night before. Oil level is full, can't see or smell diesel on the dipstick, but then again, if this just started, it may not have had enough run time to get that much fuel into the oil.


Sorry this is so long, I wanted to give the story step by step for what I've checked/done so far. So, crank no start in morning (60*F), starts for 2 different reasons on 2 different days, runs fine when started (didn't drive anywhere yet), and restarts just fine when shut off. Ideas??? Does anyone know if there is any way to test without that special fitting? Maybe something I could do with a more standard/available banjo bolt? What would your next step be?


Thanks guys!

ChuckT

I'm a novice but I, like so many others that own one of the trucks, had a similar problem.

Just 'cause the lift pump is flowing doesn't mean its functioning properly.
Fan clutch code + Running like crap = bad lift pump (quite often)
If you haven't already, I would check the fuel pressure between the lift pump and CP3 during idle and under load.
Start with the most common stuff first.

Anyone else like to chime?

tom mapes

Thanks Chuck, I will check lift pump pressure. However, it does not run like crap, runs great/perfect/normal far as I can tell. It took a couple days for my thread to post, I've been driving it, checking the oil, watching the gauges- everything seems fine, just an extended crank for the 1st start of the day- probably 7 or 8 seconds on the key?

I still can't find anyone who knows the answer to this question - my bully dog outlook can display "ICP", injector control pressure, is this "commanded" or "actual" fuel rail pressure???

Not even bully dog knows specifically, but if I'm basing troubleshooting off of the reading, I need to know if the number I'm seeing is what the ecm WANTS for fuel pressure, or what the rail sensor is SHOWING for fuel pressure...

Jeff in TD

So basically you have long crank times when cold starting, and using a battery charger helps...

My non-expert guess would be injector return flow will turn out to be high, and you end up changing injectors.

ChuckT

Tom
This is very informative so please let us know what the solution ends up being. My truck's approximately the same age...

ICP? I would think the answer lies within the acronym itself in that its an ECM request. Also, if the commanded pressure differed from the actual, the ECM may throw a code. I'm sure someone would verify that as I may be dead wrong.

So still no diesel in the oil? How about a compression test?

soulezoo

Tom,

Jeff in TD is right on the money here.

You kind of got the diagnosis yourself with the low rail pressure. What happens is after your truck sits a while, the injectors "bleed down" due to the excessive return flow. Then it takes a while to build back up while cranking. That's why it will start right back up even sitting for just a short time but will not when left overnight.

It isn't your lift pump (your truck can run with zero lift pump but will ruin the cp3 over time) but the canister mounted lift pump you have has a notoriously short life.... a lifespan you have been lucky enough to extend. You should consider a replacement while the injectors are out being rebuilt.

Hawglip

Take the FCA out and lube it with WD 40. Look on You Tube and you will see a video on it. If that corrects the problem you need to replace the FCA. The lube is just a temporary fix. I would say the FCA is the problem.

tom mapes

Hi Guys, sorry for the delay- life happened and I didn't have time to work on the truck. I had some important jobs, moved, and bought a new truck since my last post.
I brought the cummins to my diesel guy and told him I that even though I ordered my specialty tools to test pressure and return flows, I didn't have the time to mess with it anymore and that I bought a new truck anyway.
He pulled the injectors and had them tested, 4 tested bad. We put in a set of reman Bosch injectors, all done. Truck is now for sale! Thanks to everyone for their help.

heykw

link the vid please