91 FJ80 Fuel Injection Relay Issue/Relocation

[VitaminC914]

Hi, I have been having occasional issues with my fuel injection relay so I just carry a few extra in my glovebox. On a recent trip, I noticed a sudden drop in the RPM when hit a bump. I decided to check the relay and I had to pry it out. This is what it looked like on the inside. I replaced it with a new one and carried on. I am not very mechanical and I don't want to relocate the whole panel.

I am wondering what if I get 4 14ga wires with 4 connectors and run those from the relay connector to the inside of the cab and put the relay there. I can have the wires wrapped with insulated tape to help. That way, I don't have to move the whole panel and the F.I. Relay isn't impacted by the heat from the engine.

Any ideas? Thoughts? My truck is all stock with the exception of the EGR Delete.

Thank you in advance!

 

[jonheld]

That is the EFI main relay. There are many threads regarding this. It is a common issue on the 3FE equipped trucks.
Your contacts appear to be arcing due to poor contact. I would try to tighten up the female contacts if they are not damaged.
New contacts w/pigtails are available from Toyota. 82998-12060
There is also a replacement relay from a Camry 28300-16010.

 

[lanierchris]

Chasing this on 3FE trucks: nine times out of ten the relay itself isn't the problem, the female terminals in the socket are. They lose spring tension, the contact gets high resistance, it arcs, the plating burns off, and then it gets worse every heat cycle. That's exactly why you're seeing a burnt look inside the relay and why a bump drops the RPM - it's a mechanical connection going open, not a coil failing. New relays into a tired socket will keep dying.

Before you run any wire, pull the relay and look at the terminals in the block with a light. If they're just loose, you can carefully squeeze the female contacts back down with a small pick or needle-nose so the blade drags going in. If they're browned or pitted, replace the terminals with the Toyota pigtails and crimp/solder-and-seal them in - that's the real fix and it lasts. Also check the ground and the battery-side feed to that block; corroded grounds under the fender make relays look guilty.

On relocating with 14ga pigtails to the cab: I'd skip it. You'd be adding four more crimps plus a couple feet of wire in a circuit that already has a voltage drop problem, and you'd put the splices in the same harness that flexes. Heat isn't really what kills these - fretting and vibration on worn contacts is. Fixing the terminals in place keeps it stock and troubleshootable for the next guy. Keep a spare relay in the glovebox regardless, they're cheap insurance.

While you're in there, tape/label nothing and take a photo of the block layout first - it's easy to get a relay back one position off and end up chasing a no-start.

 

[VitaminC914]

Chasing this on 3FE trucks: nine times out of ten the relay itself isn't the problem, the female terminals in the socket are. They lose spring tension, the contact gets high resistance, it arcs, the plating burns off, and then it gets worse every heat cycle. That's exactly why you're seeing a burnt look inside the relay and why a bump drops the RPM - it's a mechanical connection going open, not a coil failing. New relays into a tired socket will keep dying.

Before you run any wire, pull the relay and look at the terminals in the block with a light. If they're just loose, you can carefully squeeze the female contacts back down with a small pick or needle-nose so the blade drags going in. If they're browned or pitted, replace the terminals with the Toyota pigtails and crimp/solder-and-seal them in - that's the real fix and it lasts. Also check the ground and the battery-side feed to that block; corroded grounds under the fender make relays look guilty.

On relocating with 14ga pigtails to the cab: I'd skip it. You'd be adding four more crimps plus a couple feet of wire in a circuit that already has a voltage drop problem, and you'd put the splices in the same harness that flexes. Heat isn't really what kills these - fretting and vibration on worn contacts is. Fixing the terminals in place keeps it stock and troubleshootable for the next guy. Keep a spare relay in the glovebox regardless, they're cheap insurance.

While you're in there, tape/label nothing and take a photo of the block layout first - it's easy to get a relay back one position off and end up chasing a no-start.

Thank you for the info. Very helpful. I will take a pic of the terminal on the block. I am just trying to figure out how to remove it without messing with all the wires going into the block.

 

[jonheld]

Thank you for the info. Very helpful. I will take a pic of the terminal on the block. I am just trying to figure out how to remove it without messing with all the wires going into the block.

Terminals remove from the bottom. Yes, it's a PITA to do.
You don't have to remove the terminals to compress the female contacts unless they are damaged.

 

[VitaminC914]

Terminals remove from the bottom. Yes, it's a PITA to do.
You don't have to remove the terminals to compress the female contacts unless they are damaged.

I was able to unscrew the box and look at it from the bottom. There is one wire that look like it has gotten hot (see pic), but nothing out of the ordinary.

I am still trying to figure out how to remove these female connectors from the plug. I am guessing I can push on them from the top. Assuming they come out, do I just splice the wires and put new connectors? One of them has 2 wires going into it. I also checked on the ground and it looks good. The one wire that looked like it got hot is the thickest one of them. I crimped the connectors from the top, put in some dielectric grease and put the new relay. It fit very tightly.

I am hoping this will take care of it. I do carry extra relays just to be on the safe side.

 

[jonheld]

The Toyota EWD tells you how to remove all the different types of terminals on the vehicle. It is free to download from the resources section.
The crusty wire is the load side of the EFI relay (pin 4).
Again, the issue is not the relay.

 

[rahksi]

The Toyota EWD tells you how to remove all the different types of terminals on the vehicle. It is free to download from the resources section.
The crusty wire is the load side of the EFI relay (pin 4).
Again, the issue is not the relay.

Where is this resource section. I see it referenced but I can’t find it. I’m on browser

 

[ppc]

Where is this resource section. I see it referenced but I can’t find it. I’m on browser

 

[rahksi]

View attachment 4204624

Ah. I use my phone. This is what I see.

 

[jonheld]

Menu icon (3 horizontal lines) to the left of the IH8Mud logo.