Let's baseline my grandma's neglected, (20 year old to us) 1997 LX450

Joined
Feb 7, 2022
Messages
153
Location
new york
ok I'm following this thread from someone who's having the same issue as me: Post in thread '96 fzj80 crank no start' 96 fzj80 crank no start - https://forum.ih8mud.com/threads/96-fzj80-crank-no-start.1289471/post-14533610

no CEL so that means the ECU is not ready. I'm going to buy a new fusible link with the block. it looks sketchy anyway so I might as well replace it.

20220803_095353.jpg

20220803_095417.jpg


I have a few more things I need to check:
- fuses
- wiring harness close to egr pipe
- fuel pump relay? the one close to rear driver side wheel
- fuel pressure to see if there's fuel going into the injectors?
- spray starting fluid into the throttle body?
 
Joined
Feb 7, 2022
Messages
153
Location
new york
I may have found the issue. the fuel pump connector seems to have a missing wire that may have disconnected. this should cause the ECU to not be in the ready state right?

What's the best way to test this hypothesis? check if there's fuel pressure when the ignition is ON?
20220804_133447.jpg
 
Joined
Nov 9, 2012
Messages
12,991
Location
Olathe, KS, USA
I may have found the issue. the fuel pump connector seems to have a missing wire that may have disconnected. this should cause the ECU to not be in the ready state right?

What's the best way to test this hypothesis? check if there's fuel pressure when the ignition is ON?
View attachment 3077504
No, the fuel pump on these does not run until the engine is cranking.

You would need to bypass the fuel pump from the fuel pump relay under the hood. I have not personally done it, so I'm not going to tell you which pins to jump, but if you can read electrical wiring diagrams (EWD) then you can look at the FSM and determine which pins to jump to force the fuel pump to run.
 
Joined
Feb 7, 2022
Messages
153
Location
new york
No, the fuel pump on these does not run until the engine is cranking.

You would need to bypass the fuel pump from the fuel pump relay under the hood. I have not personally done it, so I'm not going to tell you which pins to jump, but if you can read electrical wiring diagrams (EWD) then you can look at the FSM and determine which pins to jump to force the fuel pump to run.
ok I just finished downloading the manuals and EWD.
 
Joined
Feb 7, 2022
Messages
153
Location
new york
20220805_182012.jpg

OK so I checked the fuses under the hood and in the instrument panel and found a blown fuse for ignition.

what could have caused the fuse to blow? I did notice the hose going to the heater control valve was leaking there but it couldn't have caused it right? could disturbing the firewall engine wire behind the ege pipe done it?

I'll dismantle the hoses again and clamp them this time and secure the firewall engine wire and see if there are some exposed wires
 
Joined
Feb 7, 2022
Messages
153
Location
new york
Ok @BILT4ME it looks like you're on the money. On page 56 of the EWD, It is showing that the Junction block/splice point 14 is at page 32 and that page shows a diagram of the Cowl wire that looks to be running along the firewall. BTW I noted that the following components are not working when the key is in the ON position:

clock,
A/C fan (but the indicator lights turn on),
Low fan for rear heater (the Hi version works),
head unit,
OBD2 connection

diagram.PNG

cowl wire.PNG
 
Joined
Feb 7, 2022
Messages
153
Location
new york
I was halfway through replacing the fusible link and junction box but the larger nut sized, and it was covered in gunk (battery acid?)

i sprayed pb blaster and called it a day because sun was starting to set. I'm going to have to return to this Friday because I'm going back to my apt in the city. 😬
20220815_191432.jpg
20220815_192409.jpg
20220815_192533.jpg
 
Joined
Nov 9, 2012
Messages
12,991
Location
Olathe, KS, USA
Joined
Feb 7, 2022
Messages
153
Location
new york
If they are corroded, use coca-cola to remove the battery acid corrosion.
any tips to counteract the counterclockwise turn other than firmly grasping the junction block with my hand in case the coke and pb blaster isn't sufficient? 😅
 
Joined
Nov 9, 2012
Messages
12,991
Location
Olathe, KS, USA
any tips to counteract the counterclockwise turn other than firmly grasping the junction block with my hand in case the coke and pb blaster isn't sufficient? 😅
A screwdriver between the two posts to act as a lever and help you hold the square block from turning.

Replacement junction blocks are available from Wits' End or Toyota.
 
Joined
Feb 7, 2022
Messages
153
Location
new york
so with the help from the 80 series FB group, I got leverage from using the channellock to grip on the junction block while I use the ratchet to loosen the nut. She now has a new fusible link and a spare in the glovebox.

This afternoon I can now continue looking into the firewall wire harness and inspect what's causing the circuit to short.

20220819_104455.jpg


20220819_105746.jpg
 
Joined
Feb 7, 2022
Messages
153
Location
new york
You disturbed the wiring harness near the EGR. I'm guessing you have some bare, broken, or melted wires in there that you were unaware of.

Then, as you tried it you may have smoked one leg of the fusible links.

Do you have a CEL with the key in the "run" position? If not, then it will not start. You will need to diagnose what happened.

Did you get the harness plugged in on the MAF on the intake tube?

Double check all your plugs and wiring connectors.

Did you do the PHH? It's possible that you broke a wire on a sensor near that under the intake.
ok I just replaced the fusible link this morning and this afternoon I removed some parts in the way to take a closer look at that wire harness behind the EGR pipe and it doesn't look good. I see that the wrap is partly exposed but not sure if the individual wire insulation is broken. I ran out of sunlight today so I'm going to take a second look tomorrow and take some pictures. What would I do if I find melted wiring?
 
Joined
Nov 9, 2012
Messages
12,991
Location
Olathe, KS, USA
ok I just replaced the fusible link this morning and this afternoon I removed some parts in the way to take a closer look at that wire harness behind the EGR pipe and it doesn't look good. I see that the wrap is partly exposed but not sure if the individual wire insulation is broken. I ran out of sunlight today so I'm going to take a second look tomorrow and take some pictures. What would I do if I find melted wiring?
Open the loom, find all the crispy bits and strip and replace. Not an easy undertaking IMO, but I'm not a sparky.
 

Users who are viewing this thread

Top Bottom