Fuel/idle issue

Alright guys,
I’ve never had this issue before but I’m hoping some others have. My truck all of a sudden (right after I hit 200k miles)began surging while driving. The rmps will raise and lower but keep the speed the same. It will also do it at resting idle until it stalls out as I go to start from a stop. But the weird part is that it will stop after I have parked the truck for like a day or two and then won’t start doing it till maybe 30 miles later. Sometimes not till after a few days of driving. I changed the fuel filter and put in new fuel…Then it did it again. My next guess was idle air control value or fuel pump or fuel pressure regulator. My problem is that I really can’t even take it to a mechanic because the issue isn’t constantly happening and there are no codes being thrown. I also changed out the MAF sensor probably 1500 miles ago. Help! I would upload a video of it parked and the rpm’s going from 500 to 1200 but it won’t let me.

 

These can be tricky (as you already know). Why did you change the MAF, and did you use an OEM Toyota MAF? Consider checking the TPS with a multimeter?

What kind of condition are the plugs, plug wires, and coils in?

 

I changed the MAF because of a code and I used a Toyota MAF. I changed the plugs, wires and checked the coils about 10k or less ago. I’ll have to check the TPS.

 

Check all your intake piping! Could be a vacuum leak post MAF. Ive had this same issue on other cars, mostly my and my girlfriends volvo 240s. The vos behave similarly with post maf leaks

 

I had a coil pack &/or spark plug go bad at 5,000 miles. Don’t know which one so I replaced both.

 

Any update on that TPS resistance check OP?