I’m looking for help diagnosing my 1993 FZJ80

[adonay]

Symptoms:

• Starts and runs when cold.
• Runs for about 10 minutes, then dies.
• Idle is very low, around 500 RPM.
• Pressing the gas pedal only increases RPM by about 50 RPM.
• Once hot, it is very difficult to restart.
• Sometimes it will only restart if the throttle is held wide open.
• The engine will run when I spray fuel into the throttle body.

Parts Already Replaced:

• New fuel pump assembly/sending unit
• EFI relay
• Fuel pump relay
• Air Flow Meter (AFM)
• Ignition coil
• Distributor assembly cap

Additional Information:

• Fuel is reaching the engine.
• Spark plugs were not dry when checked after the issue occurred.
• No major improvement after replacing the parts listed above.

 

[efjayatee]

Maybe this:

 

[jonheld]

Symptoms:

• Starts and runs when cold.
• Runs for about 10 minutes, then dies.
• Idle is very low, around 500 RPM.
• Pressing the gas pedal only increases RPM by about 50 RPM.
• Once hot, it is very difficult to restart.
• Sometimes it will only restart if the throttle is held wide open.
• The engine will run when I spray fuel into the throttle body.

Parts Already Replaced:

• New fuel pump assembly/sending unit
• EFI relay
• Fuel pump relay
• Air Flow Meter (AFM)
• Ignition coil
• Distributor assembly cap

Additional Information:

• Fuel is reaching the engine.
• Spark plugs were not dry when checked after the issue occurred.
• No major improvement after replacing the parts listed above.

More info required.
Was it fine one day and bad the next?
Were you working on the vehicle and then had the issues?

 

[adonay]

I just bought the car a few weeks ago, the car wasn’t running when I bought it
After changing the fuel pump and relay I was able to get it running
Right now, the car idles roughly and have to open the throttle all the way for it to run

 

[adonay]

Maybe this:

View attachment 4161775

I pulled out thr coolant temp sensor and still same issue, it idles around 500 rpm with throttle all the way open

 

[jonheld]

I just bought the car a few weeks ago, the car wasn’t running when I bought it
After changing the fuel pump and relay I was able to get it running
Right now, the car idles roughly and have to open the throttle all the way for it to run

First thing I would do is download the Toyota FSM and EWD from the resources section.

Verify fuel pressure and ignition timing according to the FSM.

Are you getting error codes?

Make sure all mechanical adjustments for sensors are correct according to the FSM.

All sensors have test procedures outlined in the FSM.

 

[ToyotaTechnical]

Hey, was able to read through your post. Not much changes that we spoke about.

Replace the fuel filter
Confirm Fuel pressure at fuel rail - report back with PSI
Bypass the fuel resistor to see if fuel pressure changes

Once you get her running, properly flush that fuel tank - vacuuming out the big stuff will still leave a tremendous amount of contaminates. Check out post 5 of my other write up for the Tank cleaning process. Couple cans of B12 will also help clean up stuff.

FJ62 Revival, NM Truck Saved - https://forum.ih8mud.com/threads/fj62-revival-nm-truck-saved.1261670/

Please post photos of the engine bay. Will help gauge the situation.

 

[adonay]

This is what I was able to get done today:
- Throttle body cleaned, replaced IAC and TPS
- Made sure the resistance was correct for the TPS
- Replaced fuel filter (it was very dirty)
- Checked fuel pressure after installing fuel filter - 45 PSI
- Engine still idles around 400 rpm and the throttle opens the RPM goes only about 50 RPM high

 

[efjayatee]

Your heater T valve needs replacing ASAP..

Could it be a vacuum leak from the old hoses?

 

[adonay]

Your heater T valve needs replacing ASAP..

Could it be a vacuum leak from the old hoses?

I will work on valve replacement
I don’t think I have a vacuum, I inspected the hoses and made sure it is snug and tight

 

[efjayatee]

I will work on valve replacement
I don’t think I have a vacuum, I inspected the hoses and made sure it is snug and tight

(1) Vacuum line Diagram. | IH8MUD.com Forum | Toyota, Lexus & Off-Road Community Discussions Vacuum line Diagram. - https://share.google/n6zNyBEiWYuvpfau5

 

[jonheld]

You asked for help.
Please read post #6.

 

[adonay]

First thing I would do is download the Toyota FSM and EWD from the resources section.

Verify fuel pressure and ignition timing according to the FSM.

Are you getting error codes?

Make sure all mechanical adjustments for sensors are correct according to the FSM.

All sensors have test procedures outlined in the FSM.

I just got a gauge and performed fuel pressure test, I am getting around 42 PSI.
No error codes pops when put in diagnostic mode. The engine light just keeps flashing with no intermittent pause
- I will make sure the sensors are correct according to the FSM and report back

 

[jonheld]

I just got a gauge and performed fuel pressure test, I am getting around 42 PSI.
No error codes pops when put in diagnostic mode. The engine light just keeps flashing with no intermittent pause
- I will make sure the sensors are correct according to the FSM and report back

You keep skipping over ignition timing. This vehicle is an unknown quantity. Mechanicals must be correct first.
Have you done a compression test?
Basics basics basics first.