Ever since a couple days after I installed a flowmaster muffler my rpms have been surging in park from 500-700. Just this morning I started it , it would start fine then stall. Only way to keep it running is to give it some gas to keep the rpm's up then it will run on its own and surge. I took a look at the TB and it looks pretty clean. Could this be the iac valve or the tps sensor?

Additional Info: 98 ram 1500 Laramie slt 5.2L v8 4x4

 

yes, remove the TB and clean it and the IAC . https://dodgeforum.com/forum/dodge-r...n-the-iac.html

 

Check the IAC first. Disconnect the battery for a few minutes, and take off the air filter box so you can see the pintle. (look straight down the back of the throttle body, should be able to see it...) Have someone else turn the key to the on position, but, NOT try and start the engine. Pintle should move all the way in, and then back off a bit.... start the truck. Pintle should move smoothly to establish a stable idle. If it doesn't, it is prolly bad.

Can check the TPS with a meter, should go from just under one volt at idle position, (throttle closed) to 3.5 volts, or better, at WOT. If the needle jumps around, and you don't get a SMOOTH sweep as you step on the gas, it's bad.

Need to make sure you don't have any vacuum leaks too...... Check out the plenum thread as well.

Welcome to DF.

 

Ok turns out it was a dirty TB sprayed it with some Carb+ cleaner and runs great thanks.