I have a 1991 Toyota 4runner that when I am lightly accelerating it seems to miss or stumbles slightly between 1500 to 2200 RPM. This only started happening this week. I changed spark plugs, distributor cap, rotor wires. May check the timing tonight. Seems to idle too slow for a month when warm. I used to have a ticking that I could hear inside that was louder when I accelerated. This sound is gone. I am thinking coil is my next option but tonight I may check the timing and check for a vacuum leak. is it the igniter part of the coil that would go. Thank you for your help.

 

If it wants to idle at 500rpm when warm, then I'd check the TPS.

 

If it is the TPS is that just a setting or a replacement part? If it is a setting, how is it adjusted?

 

The TPS (Throttle Position Sensor) is on the TB, on the end of the shaft that rotates when you change the throttle position, close to the firewall.

There is a lot of useful stuff available if you do a search..

The TPS is replaceable, however you should make sure it is not just an adjustment problem, or a sticking throttle return, damper etc. Main problem on the 3VZE is that it is not easy to get at, until you get the hang of it.

You can also disconnect the TPS, and see if the hesitation clears. The ECM throws a code, but also ignores the TPS, such that a wrong position doesn't get misinterpreted.