Engine vibrates/idles at 750-800

I've done research on why these 4.0’s vibrate on low idle, so I cleaned my TB/MAF sensor/removed the secondary screen last weekend .. still no luck. I rate is not too bad where it engine dies.

2010 tacoma sport
No codes
No misfires
Has 109,603
Tune up was done at toyota @ 103,909

I’ll try to replace my spark plugs this weekend, if that don’t work I’ll borrow a scanner at work and see if any of the injectors are acting funny.

Any inputs would be appreciated.

 

What year?

 

I just read a thread today about a 2nd Gen with vibration issues and the OP used BG44 treatment and said that so far after that, issue seemed resolved. Might be worth giving that a try.

 

2010

 

Have you tried cleaning your throttle body ? My 4.0 was idling low and shaking I cleaned the throttle body and good as new !!

 

I have been running a large bottle of Techron concentrate, not the Fuel Injector cleaner, once a year through all of my FI cars for years (Euro sport cars, trucks, everything). I have notice the difference at idle several times. I'm pretty sensitive to how my vehicles run and often can tell if a CEL is going to pop before it happens. It scavenges out any moisture and cleans up injectors.

Obviously make sure your tune-up is good.

 

Any fuel system cleaner with p.e.a is good. I run Amsoil PI every three months or so.

 

Dumped Seafoam last Tuesday
Changed spark plugs/oil&filter
Found a loose PCV hose on the driver side, so I bought clamps at autozone

....it’s somewhat smoother and doesn’t get the low idle vibration feel

 

Vacuum leak could definitely have been it.

 

Huh.. I did a batt reset. Now it’s back, maybe because it hasn’t cycled readiness earlier.. after driving all day. Now it’s still gives me that low idle issue. I wonder if I have a clogged fuel filter/bad injector (but there’s no codes)/fuel pump giving out...or something else

 

How bout pulling the injectors and cleaning them. When I replaced my head gasket I noticed two of the injectors we're nasty and partially clogged. My truck purs like a new one now. It's not a difficult job, and while you are at it you can check the hoses, pcv valve, and maf sensor.

There's a way to send an electrical charge to the injectors to open them so you can spray acetone through them to clean them. There are a few other methods too I just haven't used them.

 

I've noticed when my truck is in Park and sitting idling (like waiting in a drive thru), there is a very uncomfortable undulation around 750 RPM.

If I play around with the RPM, the undulation goes away.