2002 T4R starts, then stalls, buzzing.

[Ray H]

Hi,

I just got my 4Runner back from the tranny shop. They rebuilt the tranny and replaced the radiator. When I picked up the truck from the shop last Thursday, the headlight switch was left on, but the headlights were off. We drove home and the truck would not start again. I charged the battery for 24 hours and it seemed OK. I did call the tranny shop and tell them of the problems and also said that I am wondering now about direct short to ground.

Well today my wife towed the truck home. It died on the road. She was frazzled so she can't remember exactly what happened. First it was the truck stopped running, then it was it lost power, wouldn't go anywhere and pulled over and shut it down. I went outside now that it's home and it will start for 2 seconds and then die. When the key is on, engine off, there is now a buzzing from the throttle body that started after the tranny shop. I have read of someone having a short to ground that caused the fuel pump to prime, but shut down the injectors after 2 seconds due to ECU not seeing the coils fire and saving the catalytic from fuel saturation.

Any help? This all started since the tranny rebuild.

Thanks.

 

[Ray H]

Last thing, the shop did say that it was throwing a O2 sensor fault. It has been like this since July....

 

[Ray H]

OK, here is where I am at. I went outside and the truck still stalled after 2 seconds while starting normal. I decided to press down and the gas pedal half way while starting... It started, rev'd high, then I let off the gas and it went to idle and now runs fine. It starts normal as well. When I turn off the engine but leave the key on, there is still a buzzing at the throttle body. I will be getting a scanner for codes in a bit. I am assuming now I have a TB issue. I am going to hunt out a good cleaning procedure for the TB and start there. I will also check for shorts in the harness and check intake ground locations. Any other advice would be appreciated. Anyone else with a buzzing TB?

 

[tonytwopiece]

Ok.

I would begin by checking all the connectors for anything loose or misplaced. Something isn't right and if it ran well before the shop had it, then that should have been noted and this may be their liability. I would look things over and double check connections that would cause a non running engine, like all sensors, vacuum hoses and the such.

If and when all else fails...this shop may be responsible for the matter. That is something you need to prepare for and talk to them about.

I don't know how much work you can do, or already do, on your truck...but knowing what should and shouldn't be plugged in or missing will go along way.

Also, maybe take a video of the buzzing sounds to see if someone can chime in with a similar solution to this problem. I have never heard of a throttle body making a buzzing sound, unless it has an Ihe Idle Air Control valve or something else making that sound.

 

[Ray H]

OK, went on got the codes scanned, P0420, O2/Catalytic code. No TB or TPS code thrown. URGG. Truck is running fine for me. I'm going to clean the TB and MAS today and go from there. All I can think of is the TB actuator got stuck from crud. Today is the first below freezing day here this winter, may have temperatures fooling with it. Still don't like the buzzing at the TB, but the guy at Advanced said that some TBs buzz from the sending unit to the ECU, I have never heard of that on all my cars I've owned....