Its a 98 dodge ram 1500 2WD 5.2L

It shifts good from 1st-2nd-3rd, but when it shifts from 3rd-4th it bogs down and it will hardly accelerate anymore. I keep pushing the pedal down slowly, and then it all of a sudden just jerks and takes off.

I checked the trans fluid and it was a about 1/2 quart low, filled it up, and also replaced the IAC valve, and it still bogs when it goes to fourth gear.

Ive heard it could be the TPS. Should I try changing it out?

Thanks

 

Same thing happens to me in every gear + a few other problem; oil consumption, spark knock, power loss...
Reason: Blown plenum gasket
The symptoms of a blown plenum can vary(poor acceleration, spark knock under load,etc.), but check your oil level. If the plenum plate hasn't been replaced, it's likely gone.

Your problem could be a number of things, but read the sticky'd thread about the plenum -- https://dodgeforum.com/forum/2nd-gen...um-thread.html

If your plenum checks out okay (read the plenum thread) then try a new TPS... And you can test the TPS with a multimeter to see if it's working to specs (or buy a new one if ya got $35 layin' around). Surging at highway speeds (including driving in 4th gear) can be caused by a faulty TPS so you could just throw a new one in and test it out.

 

"I keep pushing the pedal down slowly, and then it all of a sudden just jerks and takes off".

It might be the TPS, but it doesn't quite fit with the fourth gear thing. If it is the TPS, there's be a flat spot at the same point of pedal travel no matter what gear you're in. Easy enough to test though - just hook up an ohmmeter and observe the readings as it moves through its complete range of motion. Readings should be smooth and steadily changing.

If it's not the TPS, my next guess would be a problem with the transmission or its controls.

 

4th gear (O/D) is not going to give you much acceleration at all, its designed for cruising.

By "jerks and takes off", do you mean the RPMs suddenly jump up and she accelerates again? If so, thats because you dropped into 3rd gear. That is perfectly normal behavior.

 

Misfires will be most evident when the engine is smoothing out after accelerating, and shifting to fourth at a cruising speed.. the pcm may or may not pop a code..

Also, it's the prime area to first feel a clogging cat..

Cats clog most often in these rigs on the account of oil fouling.. oil fouling is most often from blown plenum gaskets...

Swap out plugs, wires, cap and rotor, and see what happens.. likely due anyway, no? While you're in there pull your throttle body and clean it.. and take a thorough look inside the intake manifold..

 

By "jerks and takes off", do you mean the RPMs suddenly jump up and she accelerates again?

Yeah, that's exactly what I meant, but just as long as it's normal. I guess I should just start driving with O/D turned off, because I very rarely get on the interstate. The fastest I ever go is about 45-50mph about 3 times a week. For seven min at most.

Thanks for your help.

 

I turn off OD when I get in, and only turn it on above 60. You might also read the plenum sticky on top of forum. A small loss in power can cause this too.

 

I'm in the same boat replace tps plugs wires cap rotor abs rear, map sensor along with new fuel pump but waiting till I get my boss to give me the aluminum plate to do the plenum. But still bucks and bogs when I hit 50 to 70 mph and toy's to stall but if I floor it I will stay alive but if I let off to soon it will start the process over if I take of od it instantly wants to bucks and act stupid. I have nothing but 44 minutes of solid highway drive twice a day for work and I've been out all week cause mines getting worse started at above 65 70 now it's if u cruse at 50 and can now happen on flat not just hills I'm str8 piped cat was stole b4 I aquire the truck 01 dodge 1500 sport 5.2l 2 wd single cab short bed. I have also noticed that I am slow to accelerate 2 me it takes a good 200 yards roughly to get to 40 50 mph.. I did have a 305 code on cylinder 5 but swapped that injector with #1 and haven't gotten a back fire code yet. But have got these new 40 sum code about evap 🤷‍♂️ but those codes r being throwin when it's buckin and sputterin. Not while just in town errands. I just bought this truck and I'm almost at what I paid for it in parts chasing this problem help please I need to get back to work.

 

What year is your truck?

 

01 ram 1500 sport 5.2l 2WRD single cab. The only thing I have noticed recently is the fact that I no Long hear like a pump of sum sort coming from front right of the truck from inside the cab when idling and also the odometer keeps blinking at me I just put in a new iac and still same once it goes from 3rd to 4th bam acts like a bitch flat or on a incline.