Lopey Idle

Hi
I have a 2002 Pre runner 3.4l that has a real lopey idle. Like it has a heavy cam. Heavy vibration. It idles about 600 - 750rpm. It runs just fine. I can go from zero to top speed and back to zero no problems. from a stop if I floor it tires lite up just fine. Two different scanners show no codes, no check engine lights. Wires, spark plugs and fuel filters are new. throttle body is cleaned out mass air flow sensor cleaned. No engine modifications plain stock 3.4l.
I have had 1 opinion/diagnosis of possible fuel injectors and or fuel pressure regulator

Has anybody had this problem. Thx -Ron

 

I believe the 02 still had the idle air control valve. 03 and up doesn't have it. I'd check out the IAC valve first. There's a couple videos on YouTube about how to change one. I'd start by cleaning it out and reinstalling. If it changes the condition it may at least give you some help in progressing with the diagnosis.

 

lopey idles are almost always because of an intake/egr leak. Bad maf reading is a fairly common cause aswell.

 

Thanks Nate. I saw the video's on you tube. My local autozone had the gasket. Pulled the t-body, removed and cleaned the IAC and the passage to the t-body. Held my breath, crossed my fingers. Turned the key and still have the same issue. I did spray brake clean around the intake and t-body with no idle change. Any other Ideas? Any and all ideas are appreciated.

 

Did you manage to figure it out? Mine breaths fire once it's moving and the idle is steady but sometimes it just works in steps rpm goes to 800 and than down to 700-725. Slight vibration.

 

I would check your vacuum lines and intake tube for cracks.

Also, I would suggest cleaning your Mass Air Flow Sensor (MAF) with a MAF cleaner (don't use anything else). It is easy and quick to do and will also rule that one out too.

 

MAF cleaned running like a Swiss watch

 

i replaced the mass air flow sensor and it didnt help.