2023 Toyota tundra

2023 Toyota tundra issue while idle at light or parked . Rough idle occasionally , not often feels like it will stall but doesn't?

 

Turn the Auto Stop/ Start off.

 

I disabled it . No auto start stop .

 

Possibly the AC compressor cycling.

 

I thought that rough idle was it switching between the two fuel injection modes.

 

Mine does the same--intermittent rough idle when stopped. I was able to directly correlate to the AC compressor engaging and putting increased load on the engine. Engine then smooths out when the compressor disengages. Just my experience.

 

My 22 does as well

It is most noticeable in the summer so I think it's the AC.

 

Unless you have the hybrid, where the A/C compressor is electrical

 

With the summer heat could also be the fan clutch engaging

 

I can definitely hear the fan when that clutch engages, and I've never experienced a "roughening" of the idle when the fan engages.

 

Agreed that it's not the fan. I also can't detect any roughness when AC engages. There's been other threads that discuss the switching between port and direct injection. I think it's the port injection that runs rougher.

 

I'm not familiar with the functionality of the port injection, but had just assumed that it created a slightly richer intake in order to "wash" the intake valves and was operational at all times. As I said, not familiar with how/when it actually comes into operation. Moot point to me; I like the idea and hopefully the end result reduces the carbon coking on the valves.

 

If true, this is interesting. They richen the port injection to clean valves? I wouldn’t think that. I think the idea is that since direct injection bypasses the valves, ‘any’ fuel from the port injectors will help reduce carbon buildup on the valves.

Previous comments sound like there is some fuel management strategy at idle that switches operation from one to the other?

 

No, you're right on the money. In the V35A, like other modern engines, DI is for efficiency. DI is more efficient than port. The only reason to have port is to prevent carbon build up. In higher performance engines (the V35A is NOT in this category) people will add port to DI engines supply sufficient fueling to maintain achieve high power output.. We're talking 800+ HP engines here...