i changed the fuel filter, fuel pump, cap, rotor, wires, plugs, iac valve, pcv, o2 sensor....

only sensor i havent changed out is the EGR valve....

anyways every morning when i start my truck to go off to work, as soon as i start driving the truck feels heavy as i take off and if i try to give it some gas it will make this deep hollow popping noising, kinda like a back fire but hollow sounding.... as the truck warms up it goes away but at random sometimes does it... any ideas???

i was throwing an EGR failure code a month ago and the truck cleared it by its self, so i dont know if its still bad or if this is even a symptom of that, i just want my truck to be responsive how it use to be...

 

The EGR is a start. Have you checked your fuel pressure? Did you check for vacuum leaks?

 

dont know how to check fuel pressure or to check for vaccum leaks? any tricks?

 

Check for vacuum leaks by getting the truck idling, take a can of ether, and spray around the engine in short little bursts. Spray vacuum hoses, around the intake and throttle body or whatever you have, basically everywhere. Listen to see if the truck's idle surges at all. If you get an increase in idle speed that means the truck is sucking in the extra fuel from a vacuum leak near where you sprayed the fluid, and start pinpointing the spot.

To check the fuel pressure, yank off the fuel line while running and see if you get a blast of gas to the face, haha.

 

whats ether??? will engine starter fluid work?

 

nope engine starter fluid didnt work haha, didnt change anything, even sprayed it directly into intake

 

Yeah ether and starting fluid are the same stuff. You say you sprayed that directly into your running intake, and it had no effect whatsoever on your idling engine? The engine is not going to surge from like 800 to 5000 rpms, usually the difference is about 500 rpms or so, but ether always has a boosting effect on every engine that I have ever touched. I mean, that is kind of its purpose in life...

I guess sometimes if you spray it into your air intake, the gas particulate can have a hard time getting past your air filter (dont spray too much on your filter, it will melt it). Try starting your engine, taking out the air filter, and sending a quick shot of spray up your intake. You absolutely should hear an engine surge. This will give you kind of a baseline for what you should be listening for when searching for vacuum leaks. Some guys use lots of other stuff, like WD-40, or even propane gas, I have had the best luck with ether.

Rarely, vacuum leaks are slight, and are only really noticeable when the truck is revving above idle speed, at 2000 rpms, for example. I had a crazy friend who would check for this by jacking up the rear and sticking the truck on cruise control, but I don't think that is all too safe. If you want to be absolutely sure that you dont have any vac leaks, check for leaks at idle, get a perfectly sized 2x4 and get the truck to rev consistently at 2000 rpms, and then check for leaks again. You can't really use an assistant to hold down the gas pedal on this one because like I said you are looking for pretty minor engine surges, and you need the engine speed to stay constant at baseline.

Also have you checked your spark plugs? Do they indicate a rich or lean mixture? This might help ferret out the cause of the prob.

Good luck

 

spark plugs looked decent but i replaced anyways...

also ive noticed the colder it gets the worse it runs, like today it was much warmer and it didnt struggle as hard

 

Well without really being there it is tough to diagnose. I am sure someone else may chime in on other diagnoses of problems acerbated by the cold, but the cold can do a number of things to a complicated engine like ours. Relays don't switch back and forth as quickly, batteries lose their juice and produce weaker sparks, etc. However, one of the biggest problems with the cold, and I believe the one which might pertain to your situation, is that when air is cold it is much denser, thus there is more oxygen contained within it. If indeed you do have a vacuum leak somewhere, then in the cold you in essence would have more of a vacuum leak, because the air leaking in provides even more oxygen, leaning the mixture out even more, and causing your truck to run even crappier. Of course, this is all based on the assumption that you do have a vacuum leak, which is yet undiagnosed, however if that is what you have then the cold would naturally make the problem worse.

The reason I mentioned your sparkers was not to suggest that they were bad, rather that they might be able to indicate whether you are burning on a rich or lean mixture. However, going back to your original symptom, what else can cause a lean mixture (which is the most common cause of backfiring, aside from poor timing)? Either too much air, or not enough fuel. So you may have holes in your air filter, vacuum leaks, or some other reason excess air is coming in. OK, what about not enough fuel? Fuel pressure may be low, you could have a clogged filter or fuel pump screen (as in my 2.5, Im not sure about the setup in your truck, where is your fuel filter?). Perhaps one of your rubber fuel lines has partially collapsed. Also, your cat may be damaged or badly decayed on the inside, however this is less likely IMO because of your cold-natured engine.

Really, I'm not very familiar with the bigger dakota engines, these suggestions are just sort of general diagnostic ideas for internal combustion machines, which I apply to my motorcycles when they start popping. However, if it were my truck this is where I would look. I have seen backfiring get dangerous cause you really dont want your gas exploding outside of the engine, especially so close to your plastic gas tank. Also, lean mixture can be detrimental to your engine, for it burns hotter, and over time will cause damage. So you are probably ok for right now I am not saying stable your truck immediately, just get on the solution of this problem asap.

 

fuel filter is under cab of truck bout 3 feet from tank, its new...

my cat is gutted out and ive had it like that for years and no issues up til now, just replaced o2 sensor this week...

i really dont think its backfiring, its not a loud bang, it almost sounds like if the truck wanted to backfire then caught it before it burped it out and swallowed it, i dont know if uve ever done that, burped with mouse closed then breathed out ur nose haha...

anyways christmas is probably gonna put a dampner on me fixing this issue, i have a throttle body gasket and plan on pull tbi off and cleaning it this weekend but thats all the money i got to spend til presents r all bought...

might have money to replace vaccuum lines also,

then if issue is still there....

ill buy intake manifold gasket, coil pack then EGR valve then map sensor? then idk what other sensors?

any suggestions in what order i should buy all this stuff?