Revving at Idle

[Gnestovia]

Ever since I've bought the car in 2018, I noticed when I start the car, at idle, it will rev up and down like I'm touching the gas pedal but I'm not. It did it once in a while. Here recently, it has gotten worse. It's now everytime I have started the car. Now I got an engine light saying there is a cylinder misfire. Forgot what cylinder, but when I put the car in gear, the revving stops or when I turn something on such as the AC. So I know it's definitely not the spark plugs or the wiring cause those are for sure good. So my guess is, could it be a bad coil or injector? Thanks!

[Mark]

Ever since I've bought the car in 2018, I noticed when I start the car, at idle, it will rev up and down like I'm touching the gas pedal but I'm not. It did it once in a while. Here recently, it has gotten worse. It's now everytime I have started the car. Now I got an engine light saying there is a cylinder misfire. Forgot what cylinder, but when I put the car in gear, the revving stops or when I turn something on such as the AC. So I know it's definitely not the spark plugs or the wiring cause those are for sure good. So my guess is, could it be a bad coil or injector? Thanks!

Some members have used Chevron Techron Fuel Injector Cleaner with good results. If I was having an issue, it's something I would try first.

[Gnestovia]

Thanks Mark, good thought. So, the cleaner, I wonder what is the best to buy? Brand wise?

[Nobu]

My dad swears by techron, I haven't had an op to compare it with anything myself. I'm using lucas fuel system treatment – don't know if it's doing any good, but it's not hurting anything and I already have it, so down the hatch it goes!

[Eggman]

The forum consensus goes with Techron as the favorite. Just be sure it's a fuel system cleaner, not an additive. Using fuel additives can be avoided by using good quality fuels such as Top Tier brands.

[Cobrajet]

How many miles?

[Top_Fuel]

...Now I got an engine light saying there is a cylinder misfire.
...Forgot what cylinder...

I assume you have the ability to read/clear OBD codes in your car? Make a note of the cylinder with the misfire. Then clear the codes and see if that misfire code comes back on the same cylinder. If it does, then I'd figure out your misfire issue first. Don't start throwing new parts at it. There are some simple things you can do for free to help diagnose the problem.

Here's another thread you may find interesting...

Erratic RPMs at idle start up Solved with fuel system cleaner

[Gnestovia]

61,250 Miles, 98,572 Kilometers.

Yes, I do have the Torque App on my Android phone this has the ability to read codes and tell me pretty much everything that is going on.

Yeah, not worth spending money on parts that isn't bad lol. That's why I wanted to ask you all for help to see what I can do.

I'll give the Techron Fuel System Cleaner first to see if it doesn't work. If not, I'll go from there. I do work as a Maintenance Technician at Toyota too so I'm learning haha. As always, I appreciate the time.

I'll give an update as well after this too.

[klroger]

61,250 Miles, 98,572 Kilometers.

Yes, I do have the Torque App on my Android phone this has the ability to read codes and tell me pretty much everything that is going on.

Is the "Torque App" something that plugs into the OBD connector?? If so, just for a goof, unplug it & try the car for a few days. There have been members with things plugged into the connector causing the cars to do all kinda weird things...

[Dirk Diggler]

61,250 Miles, 98,572 Kilometers.

Yes, I do have the Torque App on my Android phone this has the ability to read codes and tell me pretty much everything that is going on.

Yeah, not worth spending money on parts that isn't bad lol. That's why I wanted to ask you all for help to see what I can do.

I'll give the Techron Fuel System Cleaner first to see if it doesn't work. If not, I'll go from there. I do work as a Maintenance Technician at Toyota too so I'm learning haha. As always, I appreciate the time.

I'll give an update as well after this too.

Toyota tech owning a Mirage. If that isnt a ringing endorsement I dont know what is! Maybe you could ask the president of Toyota about selling its CVTs to Mitsu instead of JATCO.