1992 Landcruiser no check engine with key turned after repairs. (1 Viewer)

[Jaroberts28]

Hey guys, I recently replaced the spark plugs, wires, cap, and rotor. Noticed in the process that a hole was burned into the ignition coil so I replaced that as well. Went to starts it after the repairs and can't get it to start. It acts like it wants to but just won't. I've replaced the EFI relay and the fusible link after this happened and still nothing. Maybe a knowledgeable Minnesotan is close by to help me figure it out?

Thanks!

 

[jonheld]

When you replaced all the parts, did you unscrew the connector off of the air flow meter to remove it?

 

[Jaroberts28]

When you replaced all the parts, did you unscrew the connector off of the air flow meter to remove it?

Nah, I read through the forum prior to trying to trace down the issue and learned that was a no no.

 

[jonheld]

Hey guys, I recently replaced the spark plugs, wires, cap, and rotor. Noticed in the process that a hole was burned into the ignition coil so I replaced that as well. Went to starts it after the repairs and can't get it to start. It acts like it wants to but just won't. I've replaced the EFI relay and the fusible link after this happened and still nothing. Maybe a knowledgeable Minnesotan is close by to help me figure it out?

Thanks!

Nothing you replaced would have effected the CEL, although I wonder what ignition coil you used as the OEM one has been NLA for the last 15 years. I suggest that you retrace your steps, because clearly something is not right. I would be looking closely at connectors in the engine bay, specifically EB1 which runs the show for the ECU.

 

[Jaroberts28]

Nothing you replaced would have effected the CEL, although I wonder what ignition coil you used as the OEM one has been NLA for the last 15 years. I suggest that you retrace your steps, because clearly something is not right. I would be looking closely at connectors in the engine bay, specifically EB1 which runs the show for the ECU.

View attachment 3346264

Checked over all connections and can't seem to find anything wrong but it's hard to tell when the wires are from 1992. There are some scorch marks on the plug in for the EFI relay. Makes me wonder if the wires underneath are toast. Would no EFI relay cause no CEL on start up? Also just noticed the wires going to the cold start injector sensor are bad and showing copper. I doubt that could be the source though. New ignition coil is a Delphi btw.

 

[jonheld]

Would no EFI relay cause no CEL on start up?

Absolutely. However I would do some basic diagnostics to verify.
With the key in the OFF position, and with the efi relay removed, you should get +12 VDC at pin 2 of the EFI relay socket. No +12 = likely blown EFI fuse.
With the key in the ON position before cranking the starter, with the efi relay removed, you should get +12 at pin 3 of the EFI relay socket. No +12 means the ECU is not energizing the relay because it is not in the ready state.

 

[Jaroberts28]

Absolutely. However I would do some basic diagnostics to verify.
With the key in the OFF position, and with the efi relay removed, you should get +12 VDC at pin 2 of the EFI relay socket. No +12 = likely blown EFI fuse.
With the key in the ON position before cranking the starter, with the efi relay removed, you should get +12 at pin 3 of the EFI relay socket. No +12 means the ECU is not energizing the relay because it is not in the ready state.

Thanks! I'll give it a go after work tomorrow.

 

[jonheld]

Below is a layout of the relay box on the left fender.

 

[Jaroberts28]

Below is a layout of the relay box on the left fender.

View attachment 3347238

Below is a layout of the relay box on the left fender.

View attachment 3347238

Sorry I haven't gotten around to trying this yet it's been super hectic at work. Should have an answer for you after. I did see that the 50amp fuse was blown. I replaced it and now I have spark but it only sputters. I checked the wires and they all go to the corresponding number on the distributor. The plugs are pre gapped at .044.

 

[Jaroberts28]

Below is a layout of the relay box on the left fender.

View attachment 3347238

Below is a layout of the relay box on the left fender.

View attachment 3347238

So checked slot 2 and had power and then 3 on crank and had power. Checked the EFI fuse and it was fine. So I checked the codes with a jumper. Now in the past I always got a code for O2 sensor even though it was brand new and new wiring now the check engine just flashes meaning nothing is wrong in the system.....I'm at a loss.

 

[Jaroberts28]

So checked slot 2 and had power and then 3 on crank and had power. Checked the EFI fuse and it was fine. So I checked the codes with a jumper. Now in the past I always got a code for O2 sensor even though it was brand new and new wiring now the check engine just flashes meaning nothing is wrong in the system.....I'm at a loss.

Also a week before all this started I hit a pothole and my engine started running super rough. What was funny is a mile up the road I hit another and it was back to normal...could this be something to do with my issues or a random fluke?

 

[jonheld]

Also a week before all this started I hit a pothole and my engine started running super rough. What was funny is a mile up the road I hit another and it was back to normal...could this be something to do with my issues or a random fluke?

This screams intermittent connectivity too me. In post #5 you mentioned "scorch marks" on the EFI relay socket. This screams at me as well.
The pins of EFI relay must be seated securely in the female terminals. If they have expanded over time and are not providing good contact, then they will arc and cause you woe and strife.
You can try to close the terminals to give better contact or you can replace the terminals with new OEM available at any Toyota dealer. They come with about a 6" pigtail that you can splice in to existing wires.
Relay terminals: 82998-12060
Fuse terminals: 82998-12140

 

[Jaroberts28]

This screams intermittent connectivity too me. In post #5 you mentioned "scorch marks" on the EFI relay socket. This screams at me as well.
The pins of EFI relay must be seated securely in the female terminals. If they have expanded over time and are not providing good contact, then they will arc and cause you woe and strife.
You can try to close the terminals to give better contact or you can replace the terminals with new OEM available at any Toyota dealer. They come with about a 6" pigtail that you can splice in to existing wires.
Relay terminals: 82998-12060
Fuse terminals: 82998-12140

So I did clean the area and cleaned the connection. Not a bad idea to just replace it though. Would this cause a rough engine? I'd assume it would just cut off and not run like crap because of a pot hole.

 

[Malleus]

Electricity is funny that way

 

[LongDuck]

I know you said you replaced the EFI relay, but do you have another you can swap in as a known-good part? YEARS ago, I was going on a club run and stopped at a Subway shop for lunch, got back in and no start. I walked across the (*big) parking lot to where the guys were staging and Tools had a bag of EFI relays he had pulled and handed me one. Popped it in, and started right up.

The failure mode can either be no current to operate the switch, or the switch is fused closed. My problem was the former. Now, I keep a few spares in my glove box, because I hang out wih a lot of 80s.

I'm also grinning that I learned my vessel has an Engine Room...

 

[farmrjohn]

Below is a layout of the relay box on the left fender.

View attachment 3347238

I'm trying to help my son-in-law who is having trouble with his EFI relay. In the fuse box the socket by connector 4 has melted slightly at some point in the past. The is batter voltage to #2 and #4 is showing .5 volts. It this normal? The relay seems to get quite hot and he finds that if he removes it while at work and re-installs it will start up. How difficult is it to replace either the EFI socket or move the connectors to one of the unused sockets, in his case the A/C condenser Fan Relay or the blank on to the right of the headlight relay? Does the yellow insert itself come out or can the individual female sockets be removed? How is the best way to access the back side of the fuse/relay box? Admin-let me know if I should start a new thread.

 

[farmrjohn]

I'm trying to help my son-in-law who is having trouble with his EFI relay. In the fuse box the socket by connector 4 has melted slightly at some point in the past. The is batter voltage to #2 and #4 is showing .5 volts. It this normal? The relay seems to get quite hot and he finds that if he removes it while at work and re-installs it will start up. How difficult is it to replace either the EFI socket or move the connectors to one of the unused sockets, in his case the A/C condenser Fan Relay or the blank on to the right of the headlight relay? Does the yellow insert itself come out or can the individual female sockets be removed? How is the best way to access the back side of the fuse/relay box? Admin-let me know if I should start a new thread.

Edit: There is battery voltage to #2

 

[jonheld]

Pins 2 and 4 are the relay closure contacts. Without the relay in place and energized you should see almost nothing on pin 4.

All pins are removable, and the Toyota part numbers are in this thread above.

EFI relays typically run very hot. However, if you have bad contacts that will exasperate the issue.

 

[farmrjohn]

Pins 2 and 4 are the relay closure contacts. Without the relay in place and energized you should see almost nothing on pin 4.

All pins are removable, and the Toyota part numbers are in this thread above.

EFI relays typically run very hot. However, if you have bad contacts that will exasperate the issue.

Thanks. So the .5 volts on pin 4 is a normal reading?

I checked those part numbers. It looks like they are designed to splice onto existing wires in the harness. How is the best way to access the back side of the relay/fuse box? We can get the box loose and the backing plate off but there is not enough service loop in the harness to get to the back side. It looks like either removing the bracket between the fuse box and engine and/or the washer tank will be necessary.

We are going to try electronic cleaner with the contacts and see if that helps.

 

[jonheld]

Yea, getting to the rear of the relay box is a PITA. But it can be done with some effort.