i have a 98 3.9 4x4 sport and every so often it will "bog down" i.e. rpms up and down and when i give it gas it sounds like its back firing from the TB and get almost no throttle response. I'll pull over, shut it down and restart and then it runs fine. also i'm not throwing any codes.
i was wondering if it is my crankshaft position sensor. i had put in a new map sensor and just yesterday replaced it with the old one to see if maybe the new one was faulty, which of course, appears wasn't the case. also put in a new tps awhile back and a new IAC. it also has a fairly new fuel pump which i put in a few months back, its an airtex, could that be my issue? so far its only happened maybe 3 or 4 times, and weeks apart. i can't think of a common circumstances thats causing it.

any ideas?

 

Does it usually happen at slower speeds? I had a similar problem back when I had a 3.9. It wouldn't do it on the highway, but would through town at 30-35 mph. I started by cleaning the tb really well and tps. That helped and the problem seemed to go away for a bit but then started to come back. I ended up selling it before I completely solved the problem.

 

i've never had it happen on the highway, so at this point i'd have to say yea. but like i said, its only happened 3 or 4 times.

 

Fuel filter? IDK Ford Taurus used to do that junk.. always took the filter off dumped it put it back on and it ran like a top again... might as well check?

 

is there another filter besides the one on the fuel pump?

 

there should be one on the chassie

 

Sounds like the same problem I had, but like I said I never solved it before I sold it.

Also, I don't think there is a fuel filter on the frame. I think the only one is the one in the tank with the fuel pump.

 

Dodge are idiots for only having one in the fuel tank.. so we have to drop the tank to replace the filter.. ROFL>. let me guess is it just that little sock like on the pickup of the fuel pump?

 

wow i just went out and looked under my truck. what a shock i had when i fallowed the fuel lines from the tank all the way to the fuel rail with no filter! what was dodge thinkin!!

 

They were thinking $$ to replace the fuel pump, and do the work.. LOL!