Sonofgrace

Today is Thursday. Monday, being cold outside, I started my 95 Ram 3500 5.9l cummins, and it shook, vibrated, and smoked until such a time as it seemed to be warming up. Tuesday I started it and after about ten minutes the truck was still shaking and smoking so I decided to drive it slowly so as to get it to warm up which after about ten minutes of 35mph driving the shaking and smoking stopped and ran like a champ. ***NOTE*** This truck only has 84k original stock miles on it. Yesterday I started it up and didn't notice any significant shaking or smoking at all and after about a ten minute warm up I drove it with NO problems whatsoever- it ran like a champ. TODAY, however, after running it for ten minutes I decided to drive it slowly to force a warmup like I did on Tuesday but it never did warm up. In fact, after about 2 miles of 35 mph, 6 miles of 40mph, still shaking and smoking, finally I got to about 45mph, felt the 4th gear kick in and the shaking and smoking got violent. I'm now convinced it's not a warmup problem.....

I'm a new diesel guy so I really have very little idea of what to do.

Any ideas???

NOTE: All fluids are good, coolant and oil.

I'm current on the fuel filter, 2400 miles.

Oil pressure seems to be normal.

Smoke seems to be more blue than black. Smoke pours commensurate with the amount of throttle I give it- at idle very little smoke, whereas at 2k rmp's much smoke.

I'm perplexed. Thanks for yall's replies.

Sean Allan

I had a similar issue with my 97, 2500, 5sp, 4x4, I ended up replacing the thermostat, as the truck would not warm up properly. The Cummins Thermostats are better than the NAPA or Generic Auto Parts stores Thermostats.

CarlJensen

Have you checked the timing?

gorms

First easy thing to check would be to make sure the fuel shutoff solenoid is picking up all the way, it's located at the rear drivers side of the injection pump right on top. Only thing attached to the pump with wires leading off. It should pull up on starting the truck and stay up with the key on. While it's running rough see if you can pull it up some more.

Second guess would be cracked fuel lines sucking air. Easy way to check that is to pressurize the fuel tank through the filler neck just a few pounds and look for wet spots.

Checking for fuel pressure is always a good idea as well, a bad overflow valve or supply pump can make it run rough.

torquefan

X2. Sounds like it may be a couple degrees late.

Sonofgrace

As far as the timing goes A few months ago I and a mechanic friend had to replace the "Tappit-cover" gasket, which required removing the injection pump. Of course, putting it back on required setting the timing. So as recent as this past summer we did that.

Are y'all suggesting that it can undo itself?

Sonofgrace

As far as the shut off solenoid goes just two months ago I replaced that. I'll go and check it out but I just wanted to note that it is two months old.

Sonofgrace

I'll check the tightness of the fuel lines. I remember seeing some light seepage from one of the fuel lines on to the exhaust manifold but I haven't seen it lately.

I'm not sure how to do this:
"Checking for fuel pressure is always a good idea as well, a bad overflow valve or supply pump can make it run rough."

Thanks, I'll get out there in a minute and check the lines.

patdaly

Yes it can, usually do it quicker than that, but it can. You can check it relatively easily by using the pin method, use the timing pin on the case to bring her to zero, then the timing slot on the side of the pump should be centered in the hole, if it is not, it has slipped. ( assuming you were running stock timing or had the pump pinned for the altered timing. )

Sonofgrace

I checked the fuel lines, at the injectors and the injection pump, tightened them and not change. I'm still not sure what else on the fuel system to check.

I drained my fuel filter (I have one of those cleanable filters) and there was not H2O.

I began to replace the thermostat but I slipped while loosening the alternator belt and had to go to the hospital for numerous stitches.

I had a friend from a tranny shop do a test with no codes.

Sonofgrace

As far as the timing goes, yesterday the truck ran great whereas the two days prior, it ran rough for just a little while. Is it possible for the timing to go in and out?

infidel

Timing tends to keep slipping retarded, I've seen them slip all the way down to 6. Never seen one slip to a higher degree.
Most often slips after the timing has been changed and the gear and shaft aren't spotlessly clean or the nut isn't torqued down enough.
Timing will also slip with hp increases. As the pump has to work harder the gear is more likely to slip.

Sonofgrace

Bill, can you tell me how to check the timing? I mean, is it something a newbie can do themselves at home?

gorms

FWIW, I was refering to the fuel lines from the fuel tank to the lift pump more then anything. They are stainless steel and change over to rubber around the bellhousing, its not unheard of for any part of the line to go bad. These truck have a supply pump on the block and just a pickup tube in the tank, so its easy to suck up air and not leak any fuel out, thats why a little pressure on the lines can help show that. Air in the lines won't let it run smooth.

Fuel pressure gauge reads pressure after the lift pump, supplying the injection pump. Some folks drill/tap the banjo bolt on the supply line feeding the injection pump and run either poly or copper line to a gauge, even a cheap 60psi gauge in the cab or right under the hood. I think you can replace the bleeder screw on top of the filter housing with a 1/8" MPT connector instead of drilling/tapping. A needle valve in line is needed to smoothen the pressure spikes out. All this can be purchased at a hardware store/tractor supply/etc for pretty cheap. A clogged filter/pickup screen in tank or a bad overflow valve can cause low pressure.

Any luck checking the fue shutoff solenoid while running rough?

Sonofgrace

I did check the shot off solenoid and that wasn't it. In fact, it's a new one that I put on just two months ago.