so im still having some ideling problems with my 4runner so ths is what ive done so far new plugs (gaped),new plug wires,new cap & rotor,changed out MAFM,new TPS. now im stuck. the only other thing i can think of would be to chang out the o2 sensor?............. any ideas, or suggestions, also this is the thing thats killing me the most is that it only idels ruff/ low (200 to 100) when its in gear, but when its in P or N the idel is 800 to 1000 please help im out of ideas....................................

 

any one?

 

I just found a loose vacuum line that goes to a valve on the power steering pump. It controls engine speed, maybe you have a vacuum leak somewhere along that or some other vacuum control valve. There are plenty of vacuum lines to leak.

 

ya the 3vz has endless miles of vacume lines but ive done many vacume tests (carb cleaner spray to vacume gage tests) no leaks

 

There is a coolant temp actuated idle control solenoid in the bottom of the throttle body.

I had an idle issue with my rig and the coolant circuit was clogged, no flow.

You might check that also. I put a post on here about it, you can search under my user name.

Good luck.

 

Yes the wax valve. Im not sure how to clean it though....

 

On mine there was a ball of gunk clogging the coolant flow. I just ran hot water through it under pressue to flush it out. The valve seemed to work fine, as I could pur boiling water through it and watch the valve move forward into the restriction opening.

 

yes...... ug .....dam found out what the problem was it was a burnt exost valve on the #1 cylinder... hanks for all your help though ... hay would it be best to replace all 12 valvs or just replace the burnt valve

 

my 4runner on my last 4x4 trip befor the burnt valve

 

I know this post is old but I may be suffering from the same exact thing. How did you figure out it was a burnt valve? Did you end up replacing all of them? I am debating whether or not to pull the heads and get them re-decked, valve jobs, etc.

 

You find a burned exhaust valve by doing a compression test. A cylinder with poor compression might have a burned valve or other problems. Identifying candidates, you hook a compressed air source to the spark plug hole, my compression tester has an adapter for that, and with the cylinder at TDC on the compression stroke you listen for air escaping from the exhaust, the intake, or the crankcase. Air going into the exhaust indicates a bad exhaust valve, same for the intake, and air into the crankcase indicates ring problems.

The TRW exhaust valves on the 3VZE are subject to stretch. If your motor has 150K miles on it and you burn an exhaust valve I would suggest that you replace all of the exhaust valves.

Eugene