KRT and other diesel gurus

[Southernduck]

My 6.7 Cummins has started surging at low rpms such as when you are easing down the road at 20mph. It has a slight lope at idle but when you lightly accelerate it will surge, nothing crazy but definitely noticeable. Once you get up to 40 or more it disappears and if you get on the gas pedal it comes to life and acts like it should. Changed fuel filters the other week and it didn't make a difference and the old filters looked good. Today when I slowed down from 50 and turned in the driveway it sound rough for a second then evened out. Seems like a fuel problem to me, pump or injectors maybe? Has 61,000 miles on it and has been flawless other than a bad catalytic converter which was covered under warranty. Any thoughts?

[santeeswamper]

Injector

[KRT]

Any codes? Possibilities are endless. Bad or dirty MAP sensor, EGR, soot in EGR passage ways, bad injector or injectors etc. Get to 1/2 a tank and run 30 ounces of diesel kleen in the grey bottle thru the remaining half of tank of fuel just to see if it makes a difference.

[USMCsilver]

Curious here -- if I've never poured any additives in my truck...and I don't know if the 60k miles before I bought it had stuff added...would it be advised to add something in there now?

Also, I've had this thing a year and have put about 13k miles on it. I reckon I need to do a fuel filter soon, eh? It's one of those things on my short list, but damn finding the time.

[KRT]

It's never too late for fuel additive and I change my fuel filters every 10k max.

[smitch320]

Curious here -- if I've never poured any additives in my truck...and I don't know if the 60k miles before I bought it had stuff added...would it be advised to add something in there now?

Also, I've had this thing a year and have put about 13k miles on it. I reckon I need to do a fuel filter soon, eh? It's one of those things on my short list, but damn finding the time.

I feel the same way with most of my projects, but, 20-30 mins now is better than a few days without the truck!

[marsh chicken]

Curious here -- if I've never poured any additives in my truck...and I don't know if the 60k miles before I bought it had stuff added...would it be advised to add something in there now?

Also, I've had this thing a year and have put about 13k miles on it. I reckon I need to do a fuel filter soon, eh? It's one of those things on my short list, but damn finding the time.

Fuel filters, air filters, and oil changes are much higher on my list than fuel additives. I think a lot of that shit is snake oil. I have never seen a difference in performance or MPG when using additives.

[USMCsilver]

Got my oil done today; they don't do the fuel filters though, as I inquired.

[Steelin' Ducks]

Fuel filters, air filters, and oil changes are much higher on my list than fuel additives. I think a lot of that shit is snake oil. I have never seen a difference in performance or MPG when using additives.

X2

[KRT]

Fuel filters, air filters, and oil changes are much higher on my list than fuel additives. I think a lot of that shit is snake oil. I have never seen a difference in performance or MPG when using additives.

I don't use additives other than diesel kleen. Even with that I do it for increased injector life and that's it. Anyone that knows me or listens to what I have to say will tell you that all I believe in is diesel kleen and transmission slip additive.

Diesel fuel in the U.S. wreaks havoc on the diesel fuel system....especially injectors. Change your filters often....

[KRT]

Not that I know what I'm talking about or anything.

[marsh chicken]

Not that I know what I'm talking about or anything.

Sorry, I wasn't trying to come across like I was arguing your point. You would be one of the few who's opinion I actually do listen to. A lot of the Internet engine guru's love to push additives. Most have no basis as to why they use them or evidence of the benefits they provide. I change my filters regularly on my both my boat and truck. It's cheap insurance to me. KRT do you run diesel kleen in every fill up?

[KRT]

Sorry, I wasn't trying to come across like I was arguing your point. You would be one of the few who's opinion I actually do listen to. A lot of the Internet engine guru's love to push additives. Most have no basis as to why they use them or evidence of the benefits they provide. I change my filters regularly on my both my boat and truck. It's cheap insurance to me. KRT do you run diesel kleen in every fill up?

I didn't take it that way. I also think a lot of it is snake oil. I run diesel kleen every few fill ups.

Here is a good example of a "dirty" injector.

[Southernduck]

Any codes? Possibilities are endless. Bad or dirty MAP sensor, EGR, soot in EGR passage ways, bad injector or injectors etc. Get to 1/2 a tank and run 30 ounces of diesel kleen in the grey bottle thru the remaining half of tank of fuel just to see if it makes a difference.

10-4. Will try that. When you stand on it, it will run like a scalded dog. I notice the problem more so when I first crank it up in the morning or if it sits all day.

[Southernduck]

Any codes? Possibilities are endless. Bad or dirty MAP sensor, EGR, soot in EGR passage ways, bad injector or injectors etc. Get to 1/2 a tank and run 30 ounces of diesel kleen in the grey bottle thru the remaining half of tank of fuel just to see if it makes a difference.

Ran some diesel kleen through, about 16oz with 10 gals of fuel or so and it seems to have helped significantly. Probably should try to run some every couple of tanks I guess.

[uga_dawg]

Great to hear. I've been running it in mine based on Kevin's recommendation.

I typically run it every other tank. Never noticed a bump in mpg, but I figure it helps my injectors and protects me against bad diesel.

I only run the gray bottle. Based on my reading (may have been on here, don't remember) we don't get cold enough to worry about the antigel stuff. But I did notice the white bottle was on sale in tractor supply today and I almost got a bottle.

[KRT]

Great to hear. I've been running it in mine based on Kevin's recommendation.

I typically run it every other tank. Never noticed a bump in mpg, but I figure it helps my injectors and protects me against bad diesel.

I only run the gray bottle. Based on my reading (may have been on here, don't remember) we don't get cold enough to worry about the antigel stuff. But I did notice the white bottle was on sale in tractor supply today and I almost got a bottle.

White is for cold cold cold climates. I've never noticed mpg increase but I personally believe it does wonders on injectors.

[uga_dawg]

White is for cold cold cold climates. I've never noticed mpg increase but I personally believe it does wonders on injectors.

Any problem with running the the white bottle or just not needed?

Ie if it's 3 bucks off for the white bottle would you get the white bottle or stick to the gray?