Gen3 4Runner Acting Funny.

[Brian McVickers]

Hi,

Looking for help diagnosing.

2000 Toyota 4Runner SR5 3.4l with 235,000 miles.

Known:
Check engine light is on with a code for Bank One Lean. Possible vacuum issue.
Has been running fine regardless for past two weeks. Searching for vacuum issue to fix.

Unknown: Recent development this week.
Upon starting and driving with no warm up the engine struggles with very little power.
If I start it and let it warm up for a few minutes it drives fine.

New air filter two weeks ago.
New battery two days ago. (old battery kicked it after 7 years)
All fluids including transmission are good.

Any thoughts on the lack of power issue?

Thanks
Brian

 

[bkg]

could be anything from plugged injectors to plugged fuel filter to bad coil... But.. you need to track down the cause of the CEL first given that likely has lead to the latter issue.

 

[4runnerteq]

What kind of air filter? Sometimes they don't like oiled filter. Causes fuzz on the MAF sensor wire. They don't like to have fuzz on them.

 

[devero4]

Check fuel pressure first. Then spray around the general passenger valve cover area check for air leaks with carb clean or brake clean. Also check Calculated load with your foot on the brake and giving it gas in drive. Should be up around 80%. The Air flow meter can almost be ruled out, because that would cause a lean code on both banks and not just one. There you go, that's about 1 hour worth of drag and it didn't cost you a penny.

 

[Dopesick]

Check fuel pressure first. Then spray around the general passenger valve cover area check for air leaks with carb clean or brake clean. Also check Calculated load with your foot on the brake and giving it gas in drive. Should be up around 80%. The Air flow meter can almost be ruled out, because that would cause a lean code on both banks and not just one. There you go, that's about 1 hour worth of drag and it didn't cost you a penny.

With the symptoms, I would expect the next code to pop-up as a failed heater circuit on the B1S1 A/F or 02 sensor (this changes depending on year and 49 or 50 state vehicle).

 

[devero4]

LOL. I would say that is a pretty bold guess, while that code should have popped up from the get-go since the catalyst monitor is one trip detection

 

[Simons]

This code can also be caused by a dirty/faulty mass air flow sensor. Pick up a can of MAF cleaner, remove the MAF from the intake piping and give it a thorough cleaning. You’ll know you’re done cleaning when the can is empty. Reinstall, clear the code and let us know.


Sent from my iPad using Tapatalk

 

[Brian McVickers]

Thanks everyone!

Still digging into this, the condition has improved though as the weather is warming.

 

[Teamoatmealpie]

Just a guess- recently had temp sensor go out, it first showed as a hard start- a little rough and smelled rich, once warm no issues. Didn't want to run right when computer thinks its 40 below and richens up the air-fuel ratio like crazy. Mine ran like crap, little power and eventually stalling.