A warm welcome to the FJ80 world - Looking for an ECU.

[ToyodaDude]

Howdy friends,
I am brand new to the FJ80 world, however I'm a veteran of 80's, 90's, and 00's Toyotas. I recently (three weeks ago) purchased a fabulous example of a '91 FJ80.
Nearly immediately after bringing the vehicle home, she began exhibiting a crank, no start after being properly warmed up.
I did some very low level testing myself, and determined that I was getting neither spark, nor fuel injector pulse when symptomatic. Without warning, the condition became a constant crank, no start at all times. I went ahead and replaced the EFI relay, and fusible links to no avail. I then proceeded to bang my head against the vehicle until I practically begged my friend who just so happens to be a Master Mechanic of 10+ years to take a look. He went and checked nearly everything you fine folks suggest here on the forums, as well as applied the diagnostic materials that ALLDATA provides those who are willing to pay.

He has found that there is no power or signal going to the supply wire for the distributor. He believes the ECU has failed, and I'm inclined to believe him.

So, I'm here to ask for any insight any of ya'll might have and to see who may have a good used ECU for sale!

Cheers

 

[Romer]

Welcome, You certainly can discuss your problem and the thought on it being an ECU here, but you will have to post in the Classifieds section that you want an ECU. Normally I would have moved this post, but there is technical value in the troubleshooting and having others weigh in.

These forums have helped me learn and resolve problems over the last 20+ years that have saved a lot of time and money

Your friendly section moderator

 

[ToyodaDude]

Welcome, You certainly can discuss your problem and the thought on it being an ECU here, but you will have to post in the Classifieds section that you want an ECU. Normally I would have moved this post, but there is technical value in the troubleshooting and having others weigh in.

Your friendly section moderator

Thanks for the heads up! I apologize for my misstep, I'll make an appropriate post there!

 

[NeverFinis]

Welcome.

I believe ECU failures are rare.

I would ring out your harness. Harness failure is much less rare than ECU failure.

I am not familiar with the 3FE engine harness but the 1FZ-FE is notorious for failing near the EGR due to heat.

 

[Malleus]

You can easily rule out/confirm an ECU failure. There is a very clear diagnostic procedure in the 1991 Toyota service manual. It's in the Resources section for free download. You should pick up a copy, if you haven't already done so. The Electrical Wiring Diagram is in there too.

 

[Malleus]

FL-28 through FL-45:

 

[Malleus]

I really like the older manuals; they have far more information in them than the later ones and much more informative illustrations.

 

[jonheld]

Howdy friends,
I am brand new to the FJ80 world, however I'm a veteran of 80's, 90's, and 00's Toyotas. I recently (three weeks ago) purchased a fabulous example of a '91 FJ80.
Nearly immediately after bringing the vehicle home, she began exhibiting a crank, no start after being properly warmed up.
I did some very low level testing myself, and determined that I was getting neither spark, nor fuel injector pulse when symptomatic. Without warning, the condition became a constant crank, no start at all times. I went ahead and replaced the EFI relay, and fusible links to no avail. I then proceeded to bang my head against the vehicle until I practically begged my friend who just so happens to be a Master Mechanic of 10+ years to take a look. He went and checked nearly everything you fine folks suggest here on the forums, as well as applied the diagnostic materials that ALLDATA provides those who are willing to pay.

He has found that there is no power or signal going to the supply wire for the distributor. He believes the ECU has failed, and I'm inclined to believe him.

So, I'm here to ask for any insight any of ya'll might have and to see who may have a good used ECU for sale!

Cheers

The ECU does NOT supply +12 to the ignition coil. That comes from fusible link AM2 through the ignition switch.
With the key in the ON position, there should be constant +12 at pin 1 of the coil and pin 3 of the igniter.

The ECU does NOT supply pulses directly to the ignition coil. Ignition pulses are generated from the pick up coils in the distributor, fed to the ECU for re-timing. The ECU then feeds a pulse train to the igniter which in turn feeds pulses to the primary of the ignition coil. The secondary of the coil then feeds the distributor rotor.

Please have a look at the diagnostic document below:

General Tech - 3FE EFI Diagnostics

3FE EFI Diagnostics updated for 2020

forum.ih8mud.com

 

[ToyodaDude]

Thanks for the feedback and diagnostic information! I'll pass it all along today! I will add that we have no power at the ignition coil, igniter, or distributor. If I understand the pin out for the ECU correctly, the ECU should be supplying the distributor with power, so that the hall effect sensor inside can do its thing and therefore everything you suggest. As I stated in the original post, we have no power, at the ECU connector, going to the distributor. We do however have good power and ground on the AM1 circuit all the way from the battery to the ECU. If I'm not mistaken, that would mean that the power to the distributor has been halted, within the ECU.

Is that not correct?

Thank you all for the fantastic feedback!

 

[jonheld]

Thanks for the feedback and diagnostic information! I'll pass it all along today! I will add that we have no power at the ignition coil, igniter, or distributor. If I understand the pin out for the ECU correctly, the ECU should be supplying the distributor with power, so that the hall effect sensor inside can do its thing and therefore everything you suggest. As I stated in the original post, we have no power, at the ECU connector, going to the distributor. We do however have good power and ground on the AM1 circuit all the way from the battery to the ECU. If I'm not mistaken, that would mean that the power to the distributor has been halted, within the ECU.

Is that not correct?

Thank you all for the fantastic feedback!

Negative. The distributor does not get +12 anywhere.
The pick up coils do not require voltage. They're pick up coils. As the rotor rotates, the metal fingers pass the coils inducing voltage, creating pulses.
Only the igniter and coil get +12.

 

[ToyodaDude]

Negative. The distributor does not get +12 anywhere.
The pick up coils do not require voltage. They're pick up coils. As the rotor rotates, the metal fingers pass the coils inducing voltage, creating pulses.

Well that's the best news I've heard all week! I'll implore my friend to take a strong look at the documents provided and I'll get back to y'all ASAP!

Thank you!!

 

[jonheld]

Well that's the best news I've heard all week! I'll implore my friend to take a strong look at the documents provided and I'll get back to y'all ASAP!

Thank you!!

I STRONGLY recommend that you download the Toyota FSM and EWD. They will prevent you from going down the primrose path.
You can download it from the resources section or you can get it from the link in my signature.

 

[ToyodaDude]

I STRONGLY recommend that you download the Toyota FSM and EWD. They will prevent you from going down the primrose path.
You can download it from the resources section or you can get it from the link in my signature.

I will make certain to do exactly that!

 

[jonheld]

I will make certain to do exactly that!

Again, if you're not getting +12 to the igniter connector pin 3, and the ignition coil connector pin 1 with the key in the ON position, you need to verify fusible link AM2, which is the pink one going to the grey connector. That feeds the ignition switch which feeds +12 to all injectors, the igniter and coil, and the ECU connector E6 pin 6 which tells the ECU that the ignition switch is ON.
Also, be certain that the 7.5 amp IGN fuse in the fuse box by the driver's left knee is good.
Check fuses and fusible links with a meter, not eyeballs.

 

[ToyodaDude]

Again, if you're not getting +12 to the igniter connector pin 3, and the ignition coil connector pin 1 with the key in the ON position, you need to verify fusible link AM2, which is the pink one going to the grey connector. That feeds the ignition switch which feeds +12 to all injectors, the igniter and coil, and the ECU connector E6 pin 6 which tells the ECU that the ignition switch is ON.
Also, be certain that the 7.5 amp IGN fuse in the fuse box by the driver's left knee is good.
Check fuses and fusible links with a meter, not eyeballs.

View attachment 3736344

Allow me to clarify some details as I misspoke in the previous update. We DO actually have power at the coil and igniter, we do not have any signal or pulse out of either. We DO NOT have any wave form out of the distributor, however we're going to perform some of the tests that you fine people have provided!

I will add, that although I am the owner and have mechanical experience, these diagnostics are being performed by a professional mechanic. All the information I post, assuming I'm transposing correctly, is being tested with a professional Snap-On multimeter, as well as Snap-On digital oscilloscope.

Thank you!

 

[jonheld]

We DO NOT have any wave form out of the distributor

On the diagnostic that I posted earlier, there's a snip from the FSM regarding checking resistance of the 2 pick up coils in the distributor.
In the FSM is a spec for pick up coil air gap.
I would also verify that the distributor rotor is in fact rotating when cranking.

 

[Squash]

There is a company in California which I cannot remember, but they will send you a new flashed ECU.
I bought one a few years ago for a 1995 FZJ80 this worked like a charm.
If required I can try going back into some files for the actual vendor.

 

[Malleus]

You mean these guys?

 

[Romer]

So far we have been good at keeping this technical even identifying a place that provides ECUs, BUT lets not get into a classifieds type discussion. Wanted and for sale would get this thread moved.

Thanks

Your freindly area moderator

 

[ppc]

There is a company in California which I cannot remember, but they will send you a new flashed ECU.

Jet Performance Products in Huntington Beach is whom you are referring to. Popular product in the late 80's early 90's. Mostly voodoo as Toyota ECM's have never been cracked to the degree as other manufactures like GM.