3FE runs for a moment then dies out (1 Viewer)

[samuelsmith]

Hopefully someone can give me some advice on this. I have a 1992 FJ80 with the 3FE. It has always ran perfect for me the last 5 years or so I’ve had it. A few months ago I went on a side hill and it died out on me. I finally got it to start but from then on it will sometimes start right up and run for hours, other times it will start and die or sometimes not start at all. Currently I can’t get it to start anymore. I’ve been throwing parts at it but am running out of things to change. So far I’ve done the following based on advice from here.



New fuel pump, fuel filter

New MAF

New fuel pressure regulator

New spark plugs, wires, cap

Replaced the computer with another one

When it was running I would run my hand on all the wiring trying to get it to stall out, but never could. Everytime I check there is spark, I can loosen the banjo bolt where the fuel goes into the motor and fuel comes pouring out like it should. Anyone have any suggestions on what else to look for?



Thanks.

 

[SteveH]

You have done a lot so far. When it dies, have you tried Ether starting fluid to get it re-started? If it fires on that, then you know it's fuel and not spark. You might also remove/inspect/test/replace any fuses related to fuel or ignition. I believe there is an infamous 3F fuel relay that you should check, too - search here for info.

 

[samuelsmith]

I have went through all the fuses, I did not know about the fuel pump relay though. Will research that further.

 

[60Works]

You can check for 12V to the fuel pump via the access panel above the tank. Or install a pressure gauge at the cold start injector.

I have a rusty 62 that won't run or start on hills unless the tank is more than half full. Fill the tank and it fires right up.

 

[jcj_78FJ40]

Google EFI Main relay overheating issues for the 3FE FJ80. They are notorious for overheating. I used to carry a spare when I had one.
GL

Edit - already mentioned by @SteveH

 

[Michael Hanson]

Hi, You replaced the fuel pump and filter. Did you blow out the fuel lines before doing so?

 

[Seth S]

I would measure your fuel pressure. You can either use a gage like this: Fuel Pressure Tester Kit | OTC Tools - https://www.otctools.com/products/fuel-pressure-tester-kit

Or pick up one of the small units that you install permanently in the engine bay. This way you can verify that you are getting fuel pressure at the rail and that it’s holding.

 

[Engineer8000]

I had a circuit opening relay fail on me. I keep a spare EFI relay and spare circuit opening relay in the glove box. Symptoms of a bad COR, the truck will try to start but will not stay running after you return the key to RUN. The COR is picked up by a different coil during starting but the holding coil must be functional when you let off the starter or the fuel pump will not keep running.

 

[ChaserFJ60]

Mine did this when my MAF connector was loose

 

[fj62Dave]

Hopefully someone can give me some advice on this. I have a 1992 FJ80 with the 3FE. It has always ran perfect for me the last 5 years or so I’ve had it. A few months ago I went on a side hill and it died out on me. I finally got it to start but from then on it will sometimes start right up and run for hours, other times it will start and die or sometimes not start at all. Currently I can’t get it to start anymore. I’ve been throwing parts at it but am running out of things to change. So far I’ve done the following based on advice from here.



New fuel pump, fuel filter

New MAF

New fuel pressure regulator

New spark plugs, wires, cap

Replaced the computer with another one

When it was running I would run my hand on all the wiring trying to get it to stall out, but never could. Everytime I check there is spark, I can loosen the banjo bolt where the fuel goes into the motor and fuel comes pouring out like it should. Anyone have any suggestions on what else to look for?



Thanks.

Hi, did you ever get this figured out? I’m having the same issue

 

[HemiAlex]

Mine did this when my MAF connector was loose

Googled this just now “3FE dies after one seconds” and found this comment. My maf connector was loose after doing a bunch of small work.

Thanks. This is why people should support mud.