3FE stalled out after shifting into R, now cranks but won't start even with jumpers (1 Viewer)

[spenceradams]

Hey all, I did my digging on here as best I could between 3FE no start guides (this one, specifically) and a number of threads about various issues with no starts and stalls, but having tested a few things out I was hoping for some input as I worry it's a wiring or short problem at this point. Note: 1991 FJ80 with 3fe, american model, gas, automatic, and check engine light has been mostly continuously when driving for last several months apart from when reaching speeds above 60-70mph, strangely. I ignored this because I was experiencing no issues, hearing nothing unusual, and it would go off seemingly at random.. also I happy to choose ignorance.

Maybe some context will help the issue jump out to someone:
Two days ago cranked engine up no problem, even after sitting in the cold a week. Move it to let someone park behind me, turn engine off but realize I should back up slightly. Turn engine back on, shift to reverse, engine stalls out and dies almost instantly. This has only happened once before, while driving months ago, but I assumed it was a fluke or had been fixed by the some rewiring my mechanic did (he took it upon himself to do so and did not provide details, as I've been having electric trouble with this rig for years).
I attempt to turn back on after stall and it cranks endlessly. After so many power loss/battery issues, I was sure jumping it would work but it did not: cranking endlessly still.

Now, upon looking into this I recognize the importance of these facts:
when key is in ON position, I get no CEL light or charge lamp light, BUT I do have brake lights and dome lights, as well as A/T and seatbelt lights which indicates that maybe there's some issue with FL AM2 (I don't really know what this means apart from its place in the no start guide regarding the fusible link). Fusible link and EFI relay have both been replaced within the last six months, but I check my fusible link anyways, clean all contacts, and even swap out to a new spare just to see if it was faulty.. Nope! EFI relay contacts looked great too. So now I'm curious if it's my circuit operating relay? Or the ground? Or a short / break in a wire, maybe the AM2 considering I have brake lights and dome lights but no charge lamp? Maybe most likely is an issue with the Air Flow Meter and its delicate little hat but I haven't even learned where it is exactly, all I know if you can't mess with its two screws.

Here is where my understanding ends, and it was starting to rain to I gave up tinkering.

Sidenote: the top connector (mustard colored bit) of this white wire with red bands was unclipped from this little glass tube when I started poking around, what is this? The ground? The section I clipped back onto the tube was connected to the positive battery terminal with the fusible link.

Also, what in the hell is this red wire that's just sitting disconnected? Leading to the port in the back left of the engine bay. Please excuse my ignorance I am learning, but very slowly.

 

[CharlieS]

Looks like an old school glass fuse. And the (brass) terminals are exposed, likely to short out on something if not protected. That large red wire looks like it is extending power to the interior cabin, you should be able to follow it from where it comes in the firewall behind the glovebox. It could go anywhere. The one on my 80 goes to an ARB compressor in the cargo area and the one I put in my 200 is for rear cargo area accessories.

 

[spenceradams]

Looks like an old school glass fuse. And the (brass) terminals are exposed, likely to short out on something if not protected. That large red wire looks like it is extending power to the interior cabin, you should be able to follow it from where it comes in the firewall behind the glovebox. It could go anywhere. The one on my 80 goes to an ARB compressor in the cargo area and the one I put in my 200 is for rear cargo area accessories.

If that white wire with the red bands and the glass fuse run over to this box attached to the chassis, any idea what it is? I'd never noticed it before today, maybe it been wrapped in electricians tape before or something, but more importantly, would it relate to my charge lamp/CEL not coming up on the dash when the ignition is turned to ON?

As for the red wire, that makes tons of sense. Previous owner had it routed back there and tucked under the mats in the trunk.

 

[CharlieS]

That black box looks like a relay for a PIAA fog light harness.

Looks like a mouse has been chewing the sheathing of several of those wires. I'd be on the lookout for other mouse damage to wires.

 

[jonheld]

check engine light has been mostly continuously when driving for last several months

The CEL illuminated with the engine running is telling you that the ECU has an error code. It is unwise to ignore things like this.

I've been having electric trouble with this rig for years

What does this mean? Please be specific.

So now I'm curious if it's my circuit operating relay? Or the ground? Or a short / break in a wire, maybe the AM2 considering I have brake lights and dome lights but no charge lamp? Maybe most likely is an issue with the Air Flow Meter and its delicate little hat but I haven't even learned where it is exactly, all I know if you can't mess with its two screws.

Are you following my flowchart step by step, or are you guessing at things?
Are you seeing +12 on the screw in the relay box as stated?

Are you getting constant +12 on pin 2 of the EFI MAIN relay?
With the key ON are you getting +12 to pin 3 of the EFI MAIN relay?
Are you getting a solid ground on pin 1 of the EFI MAIN relay?

I would be checking the 15 amp EFI fuse in the relay box on the left fender, and the 7.5 amp IGN fuse in the fuse panel by the driver's left knee. Check fuses with a meter, not your eyeballs.
The circuit opening relay runs the fuel pump and it is highly unlikely to be the issue.
The AFM (air flow meter) is attached to the top of the air cleaner housing and has a forward facing flat 7 pin connector. The flexible air intake plenum runs from the AFM to the throttle body.

The only thing you should be focused on is the CEL not illuminating with the key in the ON position.

 

[spenceradams]

What does this mean? Please be specific.

Long history of no starts intermittently over several years, sometimes resolving without any change OR persisting for a few days and the resolving with no change. tough to diagnose and describe to mechanics, and on here as well where. originally had my alternator replaced, then a battery or two changed out, spark plugs swapped, even entertained changing out the starter contacts and plunger. I eventually changed the fusible link and EFI relay, but in all cases before this I would be getting no crank at all and it often seemed to be ultimately an issue of a dead or low charge battery, or power not reaching the places it needed to. what's new is the CEL and charge lamps definitely not being on, which is indeed my focus, and being able to crank at all.

Are you following my flowchart step by step, or are you guessing at things?
Are you seeing +12 on the screw in the relay box as stated?

I'm running over to a hardware store to pick up a voltage meter to test these and the other fuses you mentioned and follow the flowchart properly once I have the tool. I'm hoping it is something as known and simple as what is described here: 3. If +12 VDC in fuse box and no CEL, then suspect EFI relay/fuse and associated wiring and contacts. Many have said that the wire from the EFI fuse to the EFI relay is undersized and is the root cause of all these problems. I disagree with this. At 2500 RPM I measured 6.25 amps across the load side of the EFI relay contacts. I believe the cause of the problem is related to the heat of the manifold combined with poor crimps on the connectors in the fuse box. Over time these connectors can become corroded and resistive.

Will report back in a few hours

 

[spenceradams]

Are you seeing +12 on the screw in the relay box as stated?

Are you getting constant +12 on pin 2 of the EFI MAIN relay?
With the key ON are you getting +12 to pin 3 of the EFI MAIN relay?
Are you getting a solid ground on pin 1 of the EFI MAIN relay?

Alright, granted I'm working with a very basic voltage meter - the only one available at my nearest hardware store. ordering a one that isnt just a lightbult connected to a metal point and a ground to use later.
However:
+12 on the fusible link screw confirmed
On the EFI relay I got +12 on the two circled pins, I'm not sure which number they are or how that's ordered, but no charge on the other two and couldn't fit the ground clamp inside them

The 15A EFI fuse in the fuse box also had a charge according to my little lightbulb indicator
In the driver side knee panel, the 7.5 IGN fuse yielded nothing, but neither did any of the other fuses i tested, so I'm not sure if that's a limitation of this obviously not very well made or useful tool or something else entirely, unless somehow no power is running to the knee fuse panel. Thoughts?

 

[jonheld]

The 2 circled pins are 2 and 3. 2 should be constant +12 and 3 should see +12 with the key in the ON position. Pin 1 should be ground.
Fuse box 2 is by the driver's left knee. Since I don't know what fuses you tested and power to that fuse box comes from 2 different sources, I don't know what to tell you. You really need to be specific when doing remote diagnostics and you have to remember that I'm not looking over your shoulder.
See the documents below from the 1991 Toyota EWD.

 

[spenceradams]

Since I don't know what fuses you tested and power to that fuse box comes from 2 different sources, I don't know what to tell you.

Alright, accounting for being so unspecific (apologies), I tested each fuse in fuse box 2 with the ignition set to ON. All but the fuses circles in red showed a current.

I see the 7.5 IGN fuse is the one in the top right there, which showed a current but other 7.5 in the bottom left did not and was also indent and slightly look, I may take some plier when I get home and take a look but it was the only seemingly damaged one in there.

 

[jonheld]

Another reason to have the Toyota FSM and EWD.
The bottom left and right are slots for spare fuses.
There are no contacts/no fuse in the top right ECU-B slot in the USDM.
The slot to the left of the 30 AMP heater fuse is for a plastic fuse puller.

The other 2 fuses in question are TAIL and A/C. The A/C fuse won't be active until you're running either A/C or heat.
Both of those fuses are fed from fusible link MAIN along with 20 amp DEFOG and 10 amp STOP.

There's some sort of bastard fuse tap with 2 fuses (20 amp and 15 amp) in place of the 20 amp rear heater fuse. That looks like something I would remove immediately because it has the potential of overloading that circuit, as the feed wire was gauged for max of 20 amps, not 35.

 

[ColoradoBoy]

If that white wire with the red bands and the glass fuse run over to this box attached to the chassis, any idea what it is? I'd never noticed it before today, maybe it been wrapped in electricians tape before or something, but more importantly, would it relate to my charge lamp/CEL not coming up on the dash when the ignition is turned to ON?
View attachment 3579071

As for the red wire, that makes tons of sense. Previous owner had it routed back there and tucked under the mats in the trunk.

Looks like a power wire for a stereo amplifier...

 

[spenceradams]

There's some sort of bastard fuse tap with 2 fuses (20 amp and 15 amp) in place of the 20 amp rear heater fuse. That looks like something I would remove immediately because it has the potential of overloading that circuit, as the feed wire was gauged for max of 20 amps, not 35.

So I've removed this, though if it has had any bearing on my situation I assume the damage is done. It was put in for fog lamps by the previous owner.
But then it seems all else is in order in the second fuse box then eh?

But now I'm at a bit of a loss. CEL and charge lamps not lighting up when key is in ON is still my focus, do you reckon I should try a new EFI relay? Maybe mine did blow, despite it being new. I've seen in other threads, jonheld, you recommend the plastic housing part 28300-16010 for camrys. I may order a couple of those just to try, as I'm really dreading the prospect of towing my truck.

 

[jonheld]

So I've removed this, though if it has had any bearing on my situation I assume the damage is done. It was put in for fog lamps by the previous owner.
But then it seems all else is in order in the second fuse box then eh?

But now I'm at a bit of a loss. CEL and charge lamps not lighting up when key is in ON is still my focus, do you reckon I should try a new EFI relay? Maybe mine did blow, despite it being new. I've seen in other threads, jonheld, you recommend the plastic housing part 28300-16010 for camrys. I may order a couple of those just to try, as I'm really dreading the prospect of towing my truck.

I went back and re-read this thread and I am a bit confused. Let's go back to the beginning. Please answer yes or no to the following questions:
Is the starter cranking the motor at this point?
With the key in the ON position before cranking the starter, do you have the CEL and CHARGE lamps illuminated?

How exactly are you checking fuses? Are you pulling them and checking continuity across the fuse itself? If no please explain.

Have you checked the 15 amp EFI fuse in the relay box on the left fender?
Have you checked the 7.5 amp CHARGE fuse in the relay box on the left fender?
With all relays/fuses in place and with the key in the ON position are you getting +12 to the screw terminal in the relay box on the left fender?

Have you or anyone else messed with the AFM connector?
DO NOT REMOVE THE 2 PHILLIPS SCREWS ON THE CONNECTOR HOUSING.
There is a thin spring steel clip that simply needs to be pushed up on both sides to disconnect the AFM.
With the AFM disconnected, all fuses and relays in place, key in the ON position, does the CEL illuminate?

There is a connector under the hood EB1 which all +12 to/from the EFI relay runs through. It is located slightly forward and inboard of the 3 emissions VSVs. Be certain that this is in good shape. It has 3 wires: red/yellow stripe; yellow/red stripe; solid red. See the diagrams below.