Puke

My original reason for changing to K&N was easier airflow...and longer time between changes. I used to change my air filter and oil filters every 3,333 miles,,, but after I put the k&n in I just changed the oil filter that often and let the K&N go a long time. Maybe I will switch back to paper.
When I was a kid, nearly all air filters on our farm were the oil bath type..and for some reason I always thought they were better.. but I know that K&N is a poor excuse for a real oil-bath air filter. I don't think I've seen a real one since the 60s.

Puke

OK, kept my obd2 scanner in my truck and when the CEL light came on I stopped and plugged it in to catch it before it turned itself off again.
code p0237, turbocharger curcuit sensor or some such thing...low input. Is that the same thing as a map sensor?

jrs_dodge_diesel

Yes, that is the MAP sensor. Like I said before, it would not hurt to clean it and the IAT. You have nothing to lose by doing so. You'll need a 1¼ or 1 1/16 inch deep socket for the MAP sensor, and a 13/16" deep socket for the IAT. You can clean out both using carb and choke cleaner. Gentle use of a Q-tip helps clean them as well. If you get get 237 codes after cleaning, then I would replace the MAP sensor with a new one. If you do replace it, make sure it's a Cummins part, and not a cheap knock off.


3,000 mile air filter changes That is way overkill. Air filters can go a long time between changes depending on conditions. Remember, just because it looks dirty, doesn't mean it's restricting airflow. K&N filters can work, just cannot over oil them. IMO there are some better options too (AFE, UNI, even a BHAF).

Oil bath cleaners work well, but one for our engines would be large, and I would hate to have to clean one.

SIXSLUG

I use electric parts cleaner on the IAT, supposedly no residue or something. Mine gets a little sooty. Usually hit it every spring....

My bhaf went in in 2007. Still no register on the filterminder. Should probly spring for a new one soon!!

The old school oil bath filters were supposedly very efficient at catching dirt. The KN is a great idea, the Cummins just pulls air through it too hard when under hard loads.

Puke

I found the crack in my vacuum line. I just sealed it with silicone. When it dries I guess I will find out if the vacuum has any affect whatsoever on the map sensor or turbo circuit code. Might just be wishful thinking.

BarryG

That will have no effect on the map sensor code they are not connected in anyway.

jrs_dodge_diesel

Correct, the vacuum system does not tie in to the air intake system at all.

I've never had a vacuum guage on the truck ever, but the only time our engines could ever develop vacuum would be at idle, and it would not be very much if any.

Puke

OK, I pulled the map sensor and cleaned it,...but to tell you the truth,..on the inside it looked new still. But since it's around 18 years old..how it looks might not mean much. I put it back in and went for a freeway ride. Didn't realize how little power the truck has now. I usually don't really drive it hard...but decided to romp on it to see what would happen and it reminded me of a 1980 volkswagen diesel I used to have.

So,.. not sure if there is an easy test for that map sensor, or if it's easier just to put another one in there.
BY THE WAY....MINE TAKES A 1 1/4 INCH SOCKET, NOT A 1 3/16.
Did not clean the iat sensor yet,..but..I would guess it will look near new like the map sensor.

Puke

I may have forgot to state at the beginning of this thread.
I put in a new lift pump and fuel filter about 3 weeks ago.

I just checked my lift pump pressure. At idle it as at 10 or 11 pounds. It's a carter lift pump from autozone. I could swear they are usually around 13 or 14 psi at idle. This has me a bit bothered. And..I think 3 weeks ago when I put it in..it was at the standard 13 or 14 that all my old ones were when new. And I am pretty sure they held that pressure for around 50k miles (at idle).

Puke

OK, Went to oreillys (only place close that had one) and bought a sensor. That seems to have fixed the problem. I instantly seemed to have normal power range...rather than very low power. This morning I idle at 13 to 14 psi fuel pressure...last night it was 10 1/2 or 11. I can't figure that one out unless it had something to do with the thickness of diesel at a certain temperature?

By the way, the new sensor takes a much smaller socket and it is metric. I guess that is good for most people. A lot of folks don't have a 1 1/4 deep socket laying around. I use mine once every ten years...if that. I've got a set of williams up to 3" and most of them have just sat there and got old and rusty. But I'll never let them go because the "one" time I need one..it will be worth it to have kept them.
ok

jrs_dodge_diesel

The viscosity of diesel fuel does not change very much with temperature, so that will not change the pressure like what you are seeing.

Do you have any way to monitor the fuel pressure while driving? If not, you really should. Checking the pressure at idle won't tell you much about the condition of the pump. You need to maintain 10-15 lbs of pressure with the engine under load, especially at WOT.

Glad to hear your MAP sensor is working correctly again