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Ok, trying to chase down/ fix a seemingly random issue-
Truck sat for 10 days at New Orleans airport. Started fine and got on the highway headed home. After about 10 mins, the engine surged/ lost power/ bucked with changes in RPM. Didn't matter if I was on the gas or not, did it 3-4 times in a 1 min period and then died. Got across the 5 lanes of merging traffic to the shoulder and turned the key off. Checked everything, nothing obvious, so started it again. Started right up, ran for about 2 mins then died. There was black smoke coming from the exhaust when it died.
Towed it to a shop. First, the battery negative terminals were 'loose' and the alternator was shot. Fixed that. While on the test drive, the brake line to the rear rusted thru and failed. On shutdown, there was now white smoke and unburnt fuel coming from the exhaust. They ran a bottle of BG244 with the fuel (3/4 tank) and ... no problems after 2 hrs of driving and idling.
About 2 weeks later, when the fuel with the injector cleaner in it was just below 1/4 tank, on a flat road and 25 mph it died again. Let it sit for a minute and tried to start but it just spewed black smoke. Let it sit for 30 mins and started it up fine. While at idle, I could feel the engine knock thru the frame- not real obvious, just like it was missing, or hesitating, or ... just not running smooth. It got progressively worse until the engine quit. Not bucking or loping and no changes in RPM on the tach, just a vibration/ bump in the engine felt in the frame and it died.
Towed it to a different shop (because I live in Mobile, AL) and they couldn't find anything wrong. So they replaced the CPS and called it good.
Now, a week later or so, and it is doing it again. It hasn't quit running, but I can feel that vibration in the frame. I'd like to figure it out before I'm stuck on the roadside somewhere, again.
Things I've done/ thought-
1) Tight battery terminals
2) New alternator
3) Injector cleaner
4) new fuel filter- pressure is 72 post-filter (gauge), was at 60-65 when I changed it, black-ish but fuel is clear
5) oil change- had 13k on it (I know, I know), sample sent to Blackstone for analysis but previous had been fine
6) cleaned the AFE 6637 air filter
7) new CPS- need to call the shop and ask if OEM or aftermarket
8) HPOP was replaced 1 year ago
9) The engine coolant temp sensor hasn't been 'sending' for over a year now... stopped working when I replaced the water pump with the diesel site w/ filtration one
10) Replaced the windshield about 6 months ago- was having the phantom electrical issues associated with water running down the a pillar and into the driver's side fuse area
11) Turbo making good pressure (gauge from AIH delete)
I have an AE, just haven't used it in awhile and have been looking for PIDs to read to troubleshoot.
Ideas on what to look at next are appreciated. Thanks!
Post your PIDs and we'll chime in. Looks like you took the obvious approaches. Is your oil topped off and your fuel tank above half? Did you pull your ICP to see if it was oiled up?? Need more.......
Kinda missing the dual tank thing but. Can you get it running static and start doing a wire wiggle test.
If so, start on your drivers side, wearing no sleeves or a tie!! Start especially at the huge *** connector that's on your valve cover. (It's affectionately known in this forum) If that doesn't trigger it, try it again and inspect it completely. Your fault sounds like a wiggle test adventure. Found many on my rig with just a shake, Catalogue your movement all the way till you get up and under the dash. You'll be glad you did, and you'll find it without paying 84 clams an hour.
...About 2 weeks later, when the fuel with the injector cleaner in it was just below 1/4 tank, on a flat road and 25 mph it died again. Let it sit for a minute and tried to start but it just spewed black smoke. Let it sit for 30 mins and started it up fine. While at idle, I could feel the engine knock thru the frame- not real obvious, just like it was missing, or hesitating, or ... just not running smooth. It got progressively worse until the engine quit. Not bucking or loping and no changes in RPM on the tach, just a vibration/ bump in the engine felt in the frame and it died....
Classic lost foot symptom - Hutch mod time.
Black fuel filter and bucking is classic loose injector, but this can't rule out just bad injector O-rings.
Fuel pick ups was one of my initial 4 guesses. Along with CPS, injector o ring, and loose UVCH connector. I think the shop just replaced the CPS cuz it was a part they could throw at it!
I moved away from the fuel because my gauge was rock steady at 72 psi post filter. Would it fluctuate if the low fuel/ back pick ups was the issue?
Also, what PIDs would you recommend logging to help diagnose the injectors? I'm thinking ICP PSI, ICP Volts, IPR duty cycle, fuel injection pulse width, engine oil temp and RPM.
Are there PIDs to help check the CPS? I've been reading the OBD threads trying to piece together which PIDs go together to diagnose issues/ monitor health.
I'll also be wriggling the 42 pin connectors to see if I can make it stall. It runs fine 98% of the time.
I wouldn't do ICP and ICP volts at the same time - it's two gauges saying the same thing with a different conversion. RPMs pretty much takes care of the CPS - no CPS, no RPMs. Here's my standard list from my old AE days:
I hard-set the limits to get a consistent gauge reaction and better graphing. If one uses auto-ranging on the gauges, it can get a bit confusing from one drive to the next. Exhaust backpressure is now set to 55 MAX.
If you have a loose injector, this can cause many of the symptoms you describe - particularly the bucking. A loose injector (or more) also shows it's ugly little face by making the engine pretty knocky (with a "tink" in the late stages), bucking at mild-moderate throttle (like on a slight grade at cruise), high idle IPR (mine was points higher than normal idle IPR) with normal ICP (about 475-500 PSI ICP), black fuel filter, and smokey cold starts. When it's really loose, you'll feel a miss and the knocking/tinking sounds like the injector is trying to escape by beating its way out of the head.
Possibly a sticking IPR? Was your current one replaced when you did the HPOP? Even if it was, was it a new or rebuilt one? If rebuilt, could still be an issue.
When the IPR went out in my Excursion about 5 years ago, it was a random bucking and loss of power issue, and when it finally got to where it shut down, there was no starting it back up until the new IPR went in. The ICP sensor was a little wet with oil, but not bad, and I ran with it like that for another 3-4 years before finally replacing it as well in a moment of "proactive kindness" to avoid roadside misery.
IPR hasn't been changed, original to the truck. HPOP was not a rebuild. Got the AE working and logged some PIDs.
Graph of the ICP, IPR DC, FIPW and RPM.
I tried to attached the full excel sheet to this post.
Everything looked normal to me, maybe a little low at idle but didn't seem like it would be a problem. The truck runs fine until it doesn't, fine 98% of the time and then develops the tick and quits. Only twice in the last month, with it being my daily driver, so it may be fairly hard to track down.
I lied. HPOP is a reman and IPR is new (a year ago). Found the receipt. But the data suggests to me oil isn't the problem.
I wriggled the 42 pin and didn't get a stumble. I'll need to pull the air intake to check for chaffing.
Two questions-
1. Do I need to ohm the 42 pin to check for bad injectors? Or will the AE buzz and CCT do the same?
2. To check for good air flow I'm thinking boost, EBP and MAP. Baro too? Thoughts?
1. Pull thee chip - your data shows classic 80HP or higher hot tune. It's easier to troubleshoot the truck than the truck/chip/chip connection/tune combo.
2. UVCH link in my signature is a good idea, but that 10mm locking bolt should prevent loose connections with a wiggle. This sounds like what you suspect - chafing.
3. EBP sensor reading bad. Cleaning may help... maybe.
07-31-2016, 04:52 PM
