I still say you should test the injectors.

 

I had the same problem with my v10.. eventually it would bog all the way down even when I was flooring it. I ran fuel injector cleaner and it didn't help. I had my mechanic clean the injectors and it fixed the problem completely. The weird thing was it that it would run fine and then all of a sudden start acting real weak so I never suspected the injectors but they turned out to be the problem.

 

I've run into this before, starts out randomly and slowly gets worse with time until the truck dies out and wont start. in my case I ended up replacing the distrubuter, shaft and all. the bushing, where the cap mount and shaft meet wore out creating a dead short so no spark was gettin through. It didn't happen all at once, just started sputtering once and a while and got worse over time. would go for months without a problem sometimes. only reason if figured it out was it eventually started frying coils.
started out the same way as your problem then got alot worse.
pull the cap and check for any play whatsoever in the rotor shaft, thats not really a good test because it won't be that much. but it shouldn't have any.

could also be 100 other things allready mentioned. but don't make the mistake of assumming that because something is new it is good. I had to install 3 o2 sensors before I got a good one. 2 were junk right out of the box

 

Does your truck use any anti freeze? In 3,000 miles, mine would go through about a pint. My truck was difficult to start and seemed to have a miss as well. Took it to the local dealer for a tune-up and turns out the head had a slight crack. The lead mechanic indicated this is common for Dodge's 5.9 gasoline engine. Had to have the head replaced.

 

Try getting fuel injectors cleaned

 

^thats some good info


and yes they do crack heads. but i think he'd know if the head was cracked.

 

re-posted in this forum per a suggestion there maybe more 5.9 users in the 2nd Gen forum -


The problem zxcvbnm described is exactly what my '02 5.9 is doing.

I've had mine into the dealer and they haven't been able to diagnose. They thought it might be a check valve in the fuel tank allowing fuel to drain back into the tank and not having enough when needed until it purges the air out. Does that sound plausible?

Any help would be appreciated.
Thanks,
Effer

 

I just went through a whole bunch of issues on mine some similar some not so similar. The coolant leak was in the front of the engine at the thermostat gasket. It just seeped a little bit. The cap and rotor seems to start carbon tracking at 30k miles and I would get an intermittent miss, an easy fix I always replace it its a pain in the *** to get in there so I would rather just put a new parts in. The fuel injector pressure cleaning did wonders I had a 3M kit from the old days and albeit $26 bucks for a can it was much smoother and the response at the accelerator was very snappy for 160k. I did replace my fuel pump it had crapped out and seems to be working fine now. I would stick with basics first then progress into the deeper fixes go cheap first. I also replaced my IAC it was very carboned up in the throttle body and the pintle of the old one. This may have also accounted for the snappy response as well. The other quick check you can do and be careful you could start a fire is spray carb cleaner around the vacuum lines and listen for the engine to step up or smooth out indicating you might have a vacuum leak . I also use a propane adjustment tool, from my ford days that I use to pump propane into the valve covers to see if there is any change indicating a possible crack in the head or extremely worn valve guides probably not that but a good trick when your not sure. a gas analyzer is a great tool to have if you know someone when your doing those checks. I would even go as far as pinching off your vacuum brake booster to make sure your not leaking from their as well. Always start out simple and then try to be methodical.

My money is on the cap and rotor from all the experiences I have had with intermittent misses and stumbles.

 

The fuel pump and regulator and filter are all one big assembly in the tank just an FYI.

 

I have a 92 with the magnum 5.2 liter and I am having same kind of problems, I have replaced every single sensor in the engine, it runs fine till it gets hot then backfires, misses and tries to stall I cannot give it any gas, I have done all the same tests and cannot find the problem, one thing I did notice is when I changed the thermostat in the top of the intake the old one was covered with oil? Once the truck sits and sputters for 10 minutes I it will correct and I can drive as normal?