Sudden acceleration rpms drop/spike

[Rocko2020]

Hi guys i drive a 2002 4.7l Ram and i had a strange incident with my truck, i was in line at a drive through when my trucks rpm begans going below 1000 rpm and suddenly was spiking to nearly 2000 and the truck began pulling and acting as if i was giving it gas, the truck didnt stall which i was expecting, but would anyone happen to suspect the cause of the sudden drop/spike in rpm leading to the truck pulling itself like that? its the first time its done that, but id definitely like to make sure i prevent it in the future, was a lil spooky.

 

[Snake15eyes1998]

From the pedal to the throttle body. It's all signal. Those cable days are long gone. I would say try cleaning your throttle body. Make sure the plate moves freely. Might of been getting stuck. Could even be your idle air control valve. Its closed when the engine is at operating temperature. If it where to some how open, the engine would get more air. More RPMs in the moment. Things to look into

 

[JohnnyMac]

If your throttle position sensor is dirty or failing, it will cause that symptom as well. I believe that (like @Snake15eyes1998 mentioned) when you clean the throttle body, you can/should clean the TPS as well. Lots of how/to Youtube videos.

 

[Fast69Mopar]

From the pedal to the throttle body. It's all signal. Those cable days are long gone. I would say try cleaning your throttle body. Make sure the plate moves freely. Might of been getting stuck. Could even be your idle air control valve. Its closed when the engine is at operating temperature. If it where to some how open, the engine would get more air. More RPMs in the moment. Things to look into

The 2002 4.7 utilizes a cable driven throttle body. All 4.7's from 1999-2007 are cable driven. 2008 MY was the first year of the Drive-by-Wire throttle body for the 4.7

 

[Snake15eyes1998]

The 2002 4.7 utilizes a cable driven throttle body. All 4.7's from 1999-2007 are cable driven. 2008 MY was the first year of the Drive-by-Wire throttle body for the 4.7

Interesting, I wonder why some older vehicles still utilized the cable and some, its all signal. My 2006 5.7 hemi doesn't have a cable. A few older cars iv worked on don't have the cable either. I think both have pros and cons. On my 2001 F150 with the 5.4. It had a cable, and it became stretched. Put like 2 zip ties where the cable connects to the pedal to take up the slack.

 

[Rocko2020]

Hi guys, So i cleaned my throttle body as well as my TPS, the throttle was definitely caked in muck, but the worst of it was the idle air intake, it was burned completely black, cheaply I cleaned it rather than buy a new one and reset my pcm, and it seems to have done the trick it even fixed my issue with reving, before when I'd rev high the rpm couldn't settle and idle at a reasonable place and would fall below 600 rpm and try to stall, now it sits at a steady 650 idle even when i rev super high, thanks for all the advice guys I hope the problem stays fix for a few years or so.

 

[Rocko2020]

Scratch that ahaha, problem made a come back, but this time the throttle cuts out randomly and when i floor it it doesnt respond but than suddenly will at random work again and send me flying, it doesn't stall anymore or atleast hasn't yet it's just the sputtering at random and messed up throttling, the truck does drive normally but will act up and do the previously mentioned dance of sputtering occasionally, I'm not certain if its the tps or my fuel pump, i imagine if it was the pump it would die all together when the engine acts like it's suffocating, I'll get s new tps soon, but if it doesn't help what else could be suggested I look at?