I had the problem where my engine would surge 100-200 RPMS. It initially just did it with cruise control and now it does it other random times to...typically not during acceleration, just when maintaing a steady speed.

I replaced the TPS (got it at autozone). Seemed pretty straitforward to install. Problem though is that it is still doing the exact same thing...

What could be causing this??? Any ideas???

 

did you reset the PCM after install?


disconnect the negative battery terminal and then hold the key to the start position for 30 seconds (or overnight) and then start it and stop it 3 times, on the third time let it idle for a couple minutes then take it for a drive and it should relearn the parameters for the new sensor see if that helps

 

Yes, we did that. Should I try cleaning the TB??? All that I did before was take that TPS off and popped the other one back on...seemed TOO easy! lol

 

hmm yea and how long since you have done a full tune up? plugs wires cap rotor air filter? maybe try some of that stuff if you do plugs go champion, either stock copper, or i have heard good about the truck plugs (just NO platinum these engines dont like them)

 

I just picked up a new air filter today----haven't had a tune up yet---just got the truck last month 130k miles on it --its a 2000 5.9 SLT 4x4----got it for 2500---not too shabby

 

Maybe you have a vacuum leak. It's not unheard of to get a bad part as well. Look into exchanging the TPS you have for a new one.

 

How would I know if I have a vacuum leak?

 

Take some carb cleaner around suspect vacuum lines and spray a little over them with the engine running. It will cause the engine to rev up if there is a leak.

 

what speeds and driving conditions does the surging happen at?

a slipping torque converter lockup clutch (TCC)
causes about a 150 to 250 rpm change

the TCC can slip due to worn out frictional facings,
or too little pressure,
or bad solenoid action,
or bad electrical circuit to the solenoid on the valve body,
or most simply .... a bad ground connection that affects the entire circuit and PCM computer

 

It is pretty random when it happens, but it seems to happen most when I am applying a moderate amount of thrust to get up a hill, etc.

Example, when the cruise is on and I am driving down a level road, it really doesn't do anything...if I came to a hill in the highway, as it begins to apply more power, that is when it fluctuates by 100-200 rpms.


Now, if I were to really push down on the accelerator (gun it), it does not do this at all and applies a strong, steady thrust.