Lectrical

These pictures were taken during my month long battle with an intermittent stalling problem that caused me to lose faith in my trusty steed. My trust and admiration has since been restored. Essentially I replaced the EFI wiring in the under hood fuse box which includes both the EFI relay contacts and EFI fuse contacts. These OEM contacts that snap into the fuse box are available as "wiring harness repair" parts from Tojo. They come crimped onto 6" pigtails which I was able to remove and soldered on #10 and #12 high temp wire (McMaster #7304K17 and 7304K16). I'll have to try to dig up the part numbers or TGAPJH could tell you. Aha! Found them while I was cleaning the shop.

Fusebox Relay Contacts - 82998-12060

Fusebox Blade Fuse Contacts - 82998-12140

From the fuse box, the EFI circuit hits connector EB1 which then feeds B+ to the ECU. I replaced the whole shebang which included both fuse contacts, all 4 relay contacts, and the EFI relay side of EB1. It is labor intensive work and cannot be rushed. My truck was down for a long weekend after I was sure that I had amassed all the right parts. I needed to fabricate a contact removal tool for the fuse box contacts and the connector as my assorted picks were too short. Again, not a big deal, but time consuming.

The wires I removed were crusty and brittle from the heat of both the EFI circuit and the exhaust manifold. While I was there I replaced the stock EFI relay with one from a Camry. It is a drop in replacement and the part # is 28300-16010.

Apparently the fusible links were part of the problem as well. They were replaced using the same wire, crimped and soldered to all new termnals. While I was there I added a new run from the alternator output lug to the battery using #2 welding cable. Not to mention a bunch of new ground wires throughout the system.

Here's a random collection of thoughts on 3FE EFI diagnostics including some tasty tidbits from the FSM. I have attempted to address the, "My truck cranks fine but won't fire." issues that can occur with the 3FE electronics. It is a work in progress, so get your own FSM and EWD and have at it.