Truck Driving Jobs

Mountain Flyer · #1 03-03-2007, 06:22 AM

:cry:

Hey all, I wrote awhile back about my low oil pressure woes with my N-14 Cummins. Good news is, I had the bottom bearings and oil pump replaced, and I now have stellar oil pressure! :wink: Also, while the truck was in the shop, I had them turn the computer up to 470 hp. The truck was set at 330-430 split horsepower the way it came from Walmart (old Wallyworld International truck).

Before I took the truck in, I had once in awhile sort of a light hammering sound; I thought maybe an injector going bad...When I picked the truck up, I didn't like the way it sounded(worse) and after a couple hundred miles, I took it back to the shop. They put it on the analyzer and could find nothing wrong. The truck was making a hammering sound as I pressed it for fuel (top of hills, accelerating, etc). They checked the valves, ran injector cleaner thru it, etc.. Pronounced it fit for duty, so I headed out with a load.

Got to SLC and it was getting worse; started running on 5 cylinders occasionally. Most of the time it would run OK, but occasionally cut out.

I took it to a Cummins certified Mom and Pop shop in SLC. They analyzed it and the old pro mechanic there said he could not say for sure, nothing showing up on the computer, but he THOUGHT it was the #1 injector bad. $650 later I had a new injector in the #1 hole, and the truck is still doing what it was. The mechanic also mentioned there were like 42 "inactive" codes saying that there was an electrical short to the injectors or something of that nature. He was speaking Mechanicese, which I only understand at a first grade level. He said he told the mechanic who did the work to check my injector connections, but I never saw him do it. I took a peek at them myself; they all seem to be hooked up OK, no broken wires or weirdness is evident.

This last trip, while pulling a grade, I had an engine warning light come on during one of the engine's "spells", and it cut out the engine briefly, then recovered and ran OK. Engine was not hot or no low oil pressure or anything, it just cut out and the lights came on.

I am wondering: Would this warning light maybe show up on a computer diagnosis so that some mechanic somewhere can figur out what is wrong with my truck and fix it?

My truck pulls hills better with the horsepower turned up, and gets better mpg too. But this new problem has me losing sleep nights. The truck will run fine for awhile, then start chirping and making noise, then will cut out and run on 5 cylinders for awhile.

I am hoping one of you fellas has an i-dee-r. :roll: If not, I am gonna take the old girl out in the pasture and shoot her. :cry:

Oh, it's an N-14 Cummins Celect, in a 99 International. Has 515,000 miles on the motor and truck.

bob h · #2 03-03-2007, 01:23 PM

just beneath the air compressor, you will find a 4-pin electrical connector for the eps. disconnect it and check for oil inside connector. if there is, replace the sensor (or, have it replaced as it may require a special socket). if there isn't, you can check the sensor with a dmm... let me know if you want to do this

i would suspect based on your description, that the problem is in the actuator harness to the injectors (need fault code to validate)

check the pass-through connector at the rocker box first

the problem with this condition is that the short/open is intermittent, and might not be present while the tech pins out the harness. i would isolate the circuit (as identified by the fault code) and apply a load, then check for a voltage drop to verify the integrity of the circuit

Mountain Flyer · #3 03-03-2007, 04:15 PM

Bob thanks for the tip. You mentioned testing with the DMM let me know if you want to do this... If you have further tips on that please let me know. I am gonna print out your suggestions and take them to my mechanic; maybe you are right on the mark and this is not something they thought of.

I have found over the years (and I am NOT a mechanice) that often it is not the "big ticket item" (i.e. injector in this case) that is at fault, but simply a short in the electric. We had an airplane once and spent a couple thousand replacing the generator, voltage regulator, and I don't know what all else-- all due to a corroded ground wire! :? They finally found it and for a ten cent terminal end, corrected the fault.

Anything you can provide me will be appreciated. I will take it back to the mechanics with your ideas. 8)

dieseldogtrucking · #4 03-03-2007, 08:46 PM

By any chance did ya happen to notice, when this is happening, is your boost pressure bouncing around, or remaining steady....

Mountain Flyer · #5 03-04-2007, 08:18 PM

I guess I don't know what Boost Pressure is. I don't have a gauge for anything like that... :roll: :?

dieseldogtrucking · #6 03-05-2007, 12:26 AM

OK then, on your computer in dash, change it to the engine load screen, see if that is all over the place or holding steady. If is bouncing all over, chances are you have a bad connection to your boost sensor. Mine was acting similar, and I tracked it down to a broken wire going to my boost sensor making intermittent connections.

Mountain Flyer · #7 03-05-2007, 01:07 AM

I don't have a computer in-dash either.... but will note your idea for my mechanic in case that is the problem! Thanks! :?

Windwalker · #8 03-10-2007, 10:59 PM

When you get to the top of a hill and the truck has been acting up, have one of those INFRA-RED temp sensors... You know, the little "hand-held gun". Measure the temp at all of the cylinders, right at the surface of the block. When my injector went bad, I had hammering at an idle. The mechanic checked the temp at all the cylinders, and number 1 was running 100 degrees hotter than the rest. If you have one that is not working, the temp will be cooler than the rest. If it's working too hard, it will be hotter than the rest. The temp on the surface of the block may give you a clue as to which one is the problem.

Mountain Flyer · #9 03-14-2007, 04:08 AM

That's a good idea Windwalker. Hadn't thought of using one of those little infrared things.

I ended up replacing all my injectors. I had one "gone" and another "going" and just decided to do them all. She runs much better now. Still "hammers" a little , off and on, usually while pulling a little hill when I lug it down just a bit. That is annoying and I still don't know what's causing THAT, but at least she now is running on all six and pulling good. :wink: