2nd Gen Tacoma Idle Issues

Hows it going guys,

Two days ago my I woke up to a dead battery. I took it out and threw it on the charger for around 4 hours. Once I placed it in my Tacoma everything seemed fine, until I stopped at my first red light. I noticed this issue only happens when the car is in drive and my foot is on the brake. When waiting at the red light I noticed my car start to vibrate and the RPMs dropped below half an RPM. Feels like its about to knock out but hangs on oscillating below half and just under 1 RPM. Is this an alternator issue ? Or is this some kind of air intake issue? It makes me wonder if the alternator is bad because of the dead battery but when I hook up the multi meter I see these stats.

Battery Voltage when car is off : 12.9V

Battery Voltage when car is on (No stereo, no AC, No headlights) : 13.45 V

Battery Voltage Full load (mentioned above all on full blast) : 13.34 V

Let me know what you guys think, If you think air intake may be the culprit could someone point me in the right direction as to how to replace it.

Thanks for reading !!

 

time for a tune up. Clean your MAF sensor, change your spark plugs. Clean your throttle body. Etc.

 

I’ve had similar issues after reconnecting the battery but it’s cleared up after a few quits.

 

I would read the alternator voltage at the B+ terminal(positive red lead from VOM) and black lead to a ground. If the engine is cold I would expect to see 14.x or > voltage. If warm - 13.4 voltage.

 

Keep driving it and see if it goes away. The ECU has to relearn fuel trims after resetting the battery. Mine runs a little wonky too until I put some miles on it

 

Thanks for the reply guys Ill keep an eye on it for a couple days but I think it is time for a tune up like desertrunner24 said. This forum is awesome, seriously guys thanks!

 

i had the exact same issue. Change spark plugs. Make sure your MAF sensor is not faulty and clean throttle body. I bet its one or a combo of those things. Thats what mine was and went away afterwards.

Edit: It also happen after i disconnected the battery.

 

Like stated above: Time for a tune up. Clean you MAF, throttle body, change spark plugs. Also the truck's computer is relearning the ideal A/F ratio. When the battery dies or pull the battery out, the A/F ratio is reset to factory default so it's going to take 500-1000 miles for the truck to "learn" what is the ideal A/F ratio for your location, driving style, etc.

Main issue though is most likely dirty throttle body. My 02 GMC Sierra did the same studder, knock, and almost die at a stop sign. I cleaned the TB next chance I got and never had the issue again.

 

Your battery is dead for a reason. These trucks along with most modern vehicles do not like idiling with a sub par / bad battery. Ill bet the batt is bad and if you replace it will be much better.

Whats the date of manufacture on the battery?

 

Its funny you mention that because I had the same suspicion so today I went ahead and replaced it with a brand new one just to rule that out. The battery looked like it was in rough shape not too sure how old it was but its gone now. So far with the new battery the idling problem is there but much less noticeable. Also I see a lot of comments about MAF sensors, throttle body, and spark plugs. Are these repairs that I can do on my own? Would you recommend someone who getting into cars preform one of these repairs or cleanings? I am just starting to get into cars and am eager to learn and work on my engine. I have quite an extensive workshop and should have most tools for the job. Let me know what you guys think! Also I dont have the chance to look up what this stuff is so sorry if it sounds like im not trying im just busy at work at the moment and only really have time to reply haha

 

Try this.

Unhook the battery. Put the key in the ignition and turn it to run to drain any residual power and reset the ecu trims etc for say 15 secs, then pull the key out.

Leave the battery unhooked for another 10 min or so.

Hook the battery up.

Turn it to run BUT DONT START IT. Smoothly press the gas pedal all the way to the floor and let it back up smoothly (say push down with a 1 mississippi count and let back up with the same 1 miss count). Do that 3 times.

Turn the key off and pull the key out.

Now start it. How does she idle?


The above will calibrate the ecu to the throttle body sensor and the ecu will be better able to know where the throttle plate is at.

 

nd4spdbh Ill give that a try today will come back with an update after work !