Engine missing, skipping at idle and low rpm occurring more often

[KEssman]

Hey, my 2006 quad 4x4, auto with 73k started started occasionally skipping or missing for lack of a better way to describe it. It started several months ago on a trip to SoCal from San Jose. I haul relatively light light loads motorcycles and gear and use the truck as a commuter about 2-3 days a week. So its pretty pampered from what I read here.

As for mods I do have the TST Powermax CR I usually leave on a power setting of 1. When this first started I turned it off to 0 and it seemed to get better. Now it happens all the time and is increasing in frequency whether the tuner is off or on. PSM air box mod. One year old AGM batteries, other ones hadn't died yet, they were just acting suspect in extreme heat and cold cranking. Have some amps, sub, and stereo equipment, power inverter. Have the Carli Susp and 35" Toyo ATs.

I have gauges. Fuel pressure, Boost, EGT, and Trans temp. With the programmer on more than 1 you can really tell when your fuel filter is due to be changed, the pressure drops when you accelerate hard. I use the fleetgard from Genos and now change it every other oil change around (8-10k). I do run the Amsoil diesel fuel additives every other tank. I could stop and see what happens.

No codes. I don't notice any thing at higher rpms or speeds. Only idling and under 10 mph. I could completely unplug the programmer and see what happens? Since the tires and lift I only get 17-19 mpg and its pretty constant.

I have subscribed since 2007 and never remember reading or hearing about this with the 5.9. Any suggestions would be appreciated.

Thanks.

 

[HOBrian]

My 03 started doing the same thing, I searched TDR and found a thread about the injectors being surrounded with carbon because the truck was not run hard 176k. My truck was babied as well. No codes just a skip and black/grey smoke out the tail pipe every time she skipped. My truck needed a new clutch as we'll, so between injectors and a new clutch I solved my problem by trading it in on a new Dodge Durango Citadel.

Just found that thread...https://www.turbodieselregister.com...BED-or-stock)&highlight=Injectors+full+carbon

 

[cerberusiam]

Try the SeaFoam or CRC injector cleaner in the fuel filter housing and let it soak over night. Sounds like you have injectors hanging open, that could be wear or just gummed up from the fuel and easy use.

 

[Prairie Dog]

I tossed my TST PM because of all the hickups and codes it threw.

 

[JJPage]

I would bet PD is on the mark. Having been there, the TST is the very first thing that has to go. TST will send you a bypass plug that will remove their box from the equation, however it still leaves their wiring harness in the mix, just turning the TST to 0/0 at the controller does not remove their failing electronics from the system.

EZ, TS, TST, almost all the fueling boxes fail after a few years of use, and must be completely removed from the system before spending money on any other exercise/component.
Jess

 

[HOBrian]

Try the SeaFoam or CRC injector cleaner in the fuel filter housing and let it soak over night. Sounds like you have injectors hanging open, that could be wear or just gummed up from the fuel and easy use.

I tried the Seafoam, and not got zero results. The only thing that allowed my truck to run somewhat correct was running power service in the grey bottle. And by that I mean I ran an entire bottle, the big one at every fill up!

 

[KEssman]

Thanks so much for the suggestions. I'll try the injector cleaners. Maybe I need a 15,000 lb 5th wheel trailer to haul around. I would love a Dynomite Diesel injector upgrade if I could pull it off in Cali with our smog checks. Not ready to toss my TST yet. Appreciate the added juice when I need it. I do get an occasional code P1034 or something like it, which is always the same with the check engine light coming on. It started shortly after installed. When I called the guy at TST he said it was common. It usually clears after a few starts and stops and more miles of driving. The miss is pretty subtle at this point, but it is increasing in frequency and should be addressed.

 

[JJPage]

Well, you can lead a horse to water...

 

[KEssman]

Problem Solved! Thanks Cerberusiam. Opened the fuel filter cannister, sucked out all the particulate matter at the bottom as well as most of the fuel with a 60 cc syringe. What is that stuff anyway? Popped in a new filter and filled the cannister with the CRC Diesel fuel injector cleaner, dumped the rest in the tank. Started and ran the engine for a few minutes to get the cleaner out the injectors, then let it sit over night as you suggested. Wow! Huge difference. Smooth idle now and more power with smoother delivery through all RPMs and gears. Ten dollar fix. I will probably repeat this exercise every 8-10k miles when I change my fuel filter with every other oil change as a good preventive maintenance practice. Thanks to all.

 

[cerberusiam]

That black "stuff" is asphaltenes, one of the inherent issues with the ULSD fuels. Add in the water that ULSD is way worse for holding and you can get some NASTY sludge buildup on the tank cannister, in the filter bowl, and even on the injectors.

The conversation around additives goes back and forth with a lot of calling out of "Cummins says..." etc, etc, but, the real story is the ULSD has radically changed how it needs to be approached. ULSD will hold 50% more water than LSD and HSD. The aromatic content that kept the asphaltenes from aggregating has been removed to the point where they will accrete at lower and lower temps. Since about 75% of the fuel is recirculated to the tank on a normal basis this just increase the aggregations of these substances from the heat soak the fuel is subjected to.

Bottom line, a regimen of additives is in fact need to counteract the results of the fuel refinement process. A periodic cleaning of the injectors is also not a bad idea but there is no solid recommendation on timing to adhere to. I would guess every 30k in normal usage would be adequate with an additive package but that is just a SWAG from what I was doing on mine. It could be more or less depending on climate and fuel quality, you just have to adjust for each instance.

 

[KEssman]

What products at what intervals do you recommend to help with this? What areas should be inspected and cleaned to prevent clogging and failure of fuel system components?

 

[cerberusiam]

A regimen of diesel fuel treatment specifically for ULSD is almost mandatory any more to keep the system cleaned out and even then you get build up because the asphaltenes occure when the fuel is heated. Cramming it into the rail at hihg pressures and the engine raise the temp to where the stuff starts collecting. Along with treatment every tank a periodic cleaning with CRC of SeaFoam will help keep that to a minimum. You cannot completely eliminate it, just control the buildup.

I have used Power Servicde the whole time I have owned my truck and there was little buildup on the injectors and tubes when I chnaged tem after 220k. I was running a treatment of SeaFoam every 40-50k to clean things up.

 

[KEssman]

Having gone through 1-2 tanks of fuel since the CRC cleaning the missing at idle and low rpm is returning, though not nearly as badly. I have run the Amsoil diesel fuel additives at the Amsoil recommended concentrations of approximately 4-5 oz per 30 gallon tankful almost since new, though those products don't mention the ULSD issue. I just found the Power Service product at my local auto parts store. Do you follow the guidelines on the bottle or run it at a higher concentration. Guess I'll keep doing my homework on this and follow your advice and see how it works out. Definitely sounds like a "gunk" issue that could turn into something more involved if you don't stay on top of it. Thanks again.

 

[cerberusiam]

Just run it the recommended dosage and see what happens. You may have to increase it to find what your engine and fuel likes. There is not consistency in this fuel.

 

[KEssman]

Thats pretty bad that we've gotten to such poor quality fuel that doesn't allow our vehicles to operate properly.

 

[JCockerill]

i had same issue with my truck same year and mileage over winter when idle time was high and operating temps were low...there is a bulletin out on it. ran some injector cleaner and it cleared right up.

 

[Hootguy]

my 07 5.9 mega is doing the same thing right now,,,where do you find the CRC,,,

 

[HOBrian]

You can find it at Advanced Auto, or any good truck stop.