97' 3.4l Tacoma with engine dieing

Long time no see. I have an engine related issue with my 97 Tacoma 3.4l manual 4x4 and hope someone has experience with my issue.

Started having engine mifiries coming home from work. Just a few misfire first, progressed becoming more consistent. Totally shut off with-in 10 miles resulting in a tow. No engine light until misfire started. Light goes off as engine smoothed out and excelerated. Slight burning smell after it finally quit and i popped the hood. Towed home.

Had refueled about 150 miles prior and ran fine. A little more than 1/2 tank left.

OBDII initially gave the P0401 code. Now the code reader will not link, still links to another Toyota. EGR temp sensor replaced 3 or 4 months ago with OEM Toyota unit.

I have started it a few times but about half the time no luck. It is making a strange clicking noise in the area where the throttle(terminology?) attaches to the manifold. I can not for the life of me locate the part that has failed even with a stethoscope. When clicking is occurring (ignition on position) truck is not starting and I get the engine light. When I turn to run with no clicking or engine light, it will crank and run for a few minutes.

Any ideas? First thought fuel or fuel pump. Leaning to something else now. Also new battery, it is not the starter. New fuel tank cap

I will try to upload a video. Thanks in advance for any advice

 

Here is another thread with your same code. Maybe it can help https://www.tacomaworld.com/threads/p0401-trouble-code.750820/

 

Thanks. That helps explain my previous issue. Not helping explain why truck is not running now though. I think.

 

I can't get the video to upload. Let me try a picture. The clicking is coming from this area. Constant clicking when ignition is in the "RUN" position or it will start and run breifly.

 

Throttle butterfly (?)

 

Also new coils, plugs, timing belt and water pump about a year ago. I've owned this one since new. Not many miles, ~260k

 

Thats your throttle body. The IAC valve is the only thing on the throttle body that should be able to click. The only other thing that could click in that area would be an injector, but they have no business clicking with the motor turned off

 

Yeah!!! Many thanks! Let me see if I can verify or get a little testing of the IAC valve. Thanks again. I have been stumped

 

You are a Rockstar man. Yes the clicking was the IAC valve. She is in a good mood this evening. Cranks and runs with the IAC plugged in("RUN" ignition position) and without the IAC plugged in(runs roughly until warmed up). After about 5 minutes died and does not want to restart regardless of ignition position.

IDK... back to the fuel pump needing replaced. Maybe???

I was able to get the OBDII to read now: P0401 EGR(multiple possible issues including PCM failed). Also IBDII showed P0505 IAC valve(as expected with disconnection)

And thank you for your help

 

I have another ride. This old truck is still my favorite. Running it Monday through Friday. An old friend so to speak, old reliable

 

EDIT: several edits for clarity. Looking at
1) fuel pump and filter. Have changed the fuel filter once(OEM) ~100k ago

2) EGR parts replacement. IDK here. EGR temp sensor replaced(supposedly OEM(factory packaging from Japan via EBAY)

3) IAC valve: clean or replace. ???

I can't afford to waste money but this is my daily driver. My day job requires dependability/reliability. My 1997 Taco is my daily driver. Monday through Friday I have to be present and on time. No excuses are allowed from my employer. To add, I have a long track record here with my company. Still a failure with my employer will/can mean termination. No question, acceptance or excuses are allowed. Big company with many names and replacements available.

Dependable, reliable transportation is a requirement.

Again any experience, advise or opinions appreciated.

Thanks again and respectfully,

Spooky

 

Here is a long list of common causes of P0401.


Common Causes:

• Faulty EGR Valve:
  The EGR valve itself may be clogged, sticking open or closed, or malfunctioning.
• Clogged EGR Tube or Intake Manifold:
  Carbon buildup can restrict the flow of exhaust gases through the EGR tube and into the intake manifold.
• DPFE Sensor Issues:
  The Differential Pressure Feedback Electronic (DPFE) sensor, which measures the EGR flow, might be faulty or have electrical connection problems.
• Vacuum Leaks:
  A leak in the vacuum lines that control the EGR valve can prevent it from opening properly.
• Faulty ECM:
  In rare cases, the Engine Control Module (ECM) itself could be the cause.

 

Not a problem biddy. Honestly I'd do one thing at a time and replace the IAC first then reassess if the rough running and motor dying continues.

Minimize the number of variables at play whenever possible.