FJ62 Replacing Fuel Filter Due to Stalling

[luckylandcruiser]

Hi all,
I will be replacing my fj62 fuel filter due to stalling issues that may be led by a bad fuel pump, but first I want to replace the fuel filter to cross that off as a culprit. I have other threads about originally thinking it was the battery and replacing all components, also replaced the efi relay and it still will intermittently stall out, and also has trouble on a hot start. The original owner replaced the fuel filter, and i noticed also replaced the gas tank, but not the fuel pump. The fuel filter is easy to access on the fj62 so figured we start there - now my question is do you need to depressurize the system or is this not necessary? I've seen different ways like unscrewing the gas cap or unplugging the open circuit relay while the car is running.

 

[Lead Head]

Unscrewing the gas cap won't do anything. Just crack the nuts loose on the filter. You'll get some gas spray so close your eyes and keep your mouth closed, and it will be fine.

 

[bubfuji]

A few points.
1. The hot start issue is almost always the fuel pressure regulator.
2. There is also a VSV (driver side fender) connected to the fuel system that increases fuel pressure slightly when the engine is hot. With a hot engine, gas in the fuel rail starts to boil/vaporize. The VSV helps the fuel pressure regulator push through gas vapers. Replace the fuel pressure regulator, and check the middle VSV for blockage or bad solenoid. Energize the VSV with 12 volts to see if the VSV clicks and try to blow air when you energize the VSV. I think the fuel VSV is normally closed. There is an engine temperature sensor that tells the ECU when to energize the FUEL UP circuit when hot. Which is why the rig will start when the engine is cold.
3. Check your vacuum line(s) condition as well.

You mention the rig suddenly dies. The engine stops like it's out of gas, kinda chug, chug and dies. Or just BAM, the engine dies. If the engine suddenly dies, the ecu is loosing power. Check your battery clamps and fusible link connections. The fusible link is attached to the positive battery terminal. Part of the fusible link feeds the ECU directly.

My FJ62 would suddenly die when going over speed bumps. The positive battery clamp (lead type) was cracked clean through and would separate enough to kill power to the ECU.