FZJ80 engine cuts off while driving and won't start

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My son, who is a student at SFSU and is in SF right now, calls me today and says engine cut off while driving. He tows it to a repair shop in SF and a few hours later the mechanic says it's the computer board failed. I have a question, what are the symptoms when the ECU fails?

Based on what my son is saying it sounds like it's a fuel problem. I've read posts on the fuel pump, fuel pump relay, resistor, clogged fuel filter, etc. He says when he tries to start the engine, it sounds like it's out of gas. The starter turns, but engine won't start. [Correction: The engine doesn't crank...just makes the electric noise for a fraction of a second when you turn the key]

He said a couple of days ago the 80 ran super rough for about 10 minutes and the problem went away for 2 days. About 6 moths ago, we replaced the intake hose with a new Toyota OEM one. The 80 ran great for 6 months until this week when he was planning to drive home to LA.

He has the scangauge ii attached and no new engine codes prior to engine cutting off. Only the old P0133 and P0130 codes which he had been clearing.

I don't know what shop he has the 80 in, but anyone know of a good 80 shop in SF that could help him? He has AAA and can get the 80 towed there. The Toy Shop seems super busy.

Oh, this is a 1996 with 230k miles now. Original fuel lines, fuel pump relay, fuel pump, etc. I don't think the fuel lines have been touched in the past.
 
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I have a similar problem with my 91. It wants to start but as soon as you let of the key it dies like it's out of gas. I replaced the fuel pump & it still does it. so I did the paper clip trick(w/wire) to keep fuel pump on & it works fine been driving it like that for 4 months.
 
How's the EFI fuse look? I've had mine blow a number of times - based on the symptoms, it could be the fuel injection fuse...
Haven't heard the ECU failing though...but stranger things could happen.

if it is the EFI fuse...then the trick would be to figure out why it's blowing...
 
Me either I figured if I said something someone else would jump in. Did he check the fuel pump?
 
If it only happens once the engine gets hot, then that tends to point to an electrical issue. Does it still have spark when it won't start? If it does, then you know it is a fuel problem. The fuel pump relay would be my first place to look as it is a fairly common problem once these engines get so many miles on them. Other sensors will throw a code, but the fuel system is still pretty "dumb" and the computer doesn't know anything about it.
 
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ps never ever had a bad ECU can happen but not very likely
 
Thanks for the advice. I happen to have the 96 FSM, so I'm looking through there for information.

The engine cutting off basically happened once.

Correction: The engine doesn't crank, but just makes initial electric noise for fraction of second
 
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I have a similar problem with my 91. It wants to start but as soon as you let of the key it dies like it's out of gas. I replaced the fuel pump & it still does it. so I did the paper clip trick(w/wire) to keep fuel pump on & it works fine been driving it like that for 4 months.
Not relevant to a 96, but your problem is the switch or logic in the AFM in your 91. You should start another thread to avoid confusion.
 
I have a similar problem with my 91. It wants to start but as soon as you let of the key it dies like it's out of gas. I replaced the fuel pump & it still does it. so I did the paper clip trick(w/wire) to keep fuel pump on & it works fine been driving it like that for 4 months.

Not really relevant to the OBD2 vehicles. Maybe a new thread?
 
The 80 is at A+ now. My son tried to start it this morning while at the other SF repair shop and it doesn't crank at all. It just makes the electric noise for a fraction of a second when you turn the key. Diagnosis might not be available until early next week.
 
starter ?

and check the wiring at the EGR tube - weird things happen when it's melted
 
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I replaced the starter contacts two years ago. Since the 80 died while driving, I doubt it's the starter. I told my son to start the 80 in the morning while cold and it didn't start. I feel better that the 80 is at a shop whose owners know 80s, but I'm worried it's the ECU...
 
Since it won't crank and it died while driving, it would highly likely be an electrical fault versus a bad ECU.

As others have posted, check the fusible links (better yet, replace them). Everything to do with starting the vehicle with the key and having it running relies on the fusible links....

Could be something as simple as bad/loose battery cables/clamps or even a failed battery.

Anyhow, all moot now that it's at a shop. At least the fault is not intermittent so should be easy to track it down.

cheers,
george.
 
I had engine cut off on me while driving in a 96. Would not run but starter would turn. Efi fuse blew. Replaced and blew again. Pulled o2 sensor harness and put in new efi fuse and ran fine. Traced it back to a shorted wire going to the passenger side of the tranny for a sensor. From my reading the o2 sensors and that part of the harness can blow the efi fuse. Repaired the wire section and no further prolems. May not be your issue as you get no starter sound. Definetly check the fusible links.
 
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