2004 ram 3500 bogs down at WOT

[J W Voita]

Hi guys,
Hope someone has the fix for this. I have a 2004.5 ram 3500. 180,000 miles auto trans, airdog lift pump. Ran great until one day i was pulling a load up a long climb on the interstate. At about 3/4 throttle and 65 mph SUDDENLY the engine lost power and bogged down to where i could only do 35mph. If I pushed it to WOT it would backfire. Engine never died, but if I kept pushing it, it would began surging and then bogging and continue in that pattern over and over. Once I got rid of my load and was on level ground I ran fine until I got on it. At WOT, even on the flat it would do the same thing. Under any condition, at idle it runs as smooth as ever. If I drive it easy on flat ground, you would never know there was a problem, but it won’t “pull your hat off”. FEELS LIKE it’s running out of fuel!
Ive covered all the usual bases. Lift pump-good, new filters, clean fuel. Good fuel pressure to the CP3. New Bosch Injectors are only 2 years old and had been doing great. Anybody know what’s up?

 

[bcbender]

Sounds like maybe an turbo issue? how much boost is it making when it happened? My 2020 had the same issues (no backfiring) but no / low boost due to a faulty EGR valve and I could not pull at all... empty it ran just fine.

 

[BigPapa]

Agree, sounds like a loss of boost pressure. I'd lean toward a boot blowing off. Does it black smoke bad when it won't pull?

 

[Ozymandias]

Need to know what boost does, definitely.

 

[J W Voita]

Two clues led me to the cause of this problem. I thought I would share those with you in addition to my $30 fix. First clue was noted on a test drive where the problem of the engine bogging down persisted and when i gave it full throttle it backfired. A very loud pop and I could see in my side mirror flames coming from the tail pipe. But if the engine was starving for fuel why was unburned fuel coming from my tail pipe like a torch? And then it occurred to me that the equivalent of too much fuel, overfueling, was not enough air. If the engine was not getting enough air, the air fuel mixture would be too rich. As soon as that mix found the air it needed it would ignite. In this case when the mix was expelled from the combution chamber and voila, we have a backfire. When I took the air cleaner cover off and saw the crown in the top of the filter element, i knew i had my bad guy. Sure enough, the filter was full of real fine red blow-sand. Installed a new filter and never had another occurrence of this problem.

 

[sag2]

Always check the easy stuff first!