80 series will start, run about a min, shutoff then not start. What is going on?

[BT80]

Hello all. So I've got a strange issue with my 1FZ-FE. I'll give you the scenario leading up to the issue, then symptoms, then what I've tried in troubleshooting and fixing.

So I went for about a 90 mile drive to the in laws, then later that day drove back home, another 90 miles. Shut the LC down, left it be for the night.
Woke up the next morning, cranked up per usual. I waited in the truck a few moments for it to warm up, then out of nowhere the engine shut off, dash lights on as usual for the ignition position, no CEL. I proceeded to crank it again, cranked up as usual ran normal for a while then stumbled (CEL) flashed during the stumble but did not create a held code or a log. Then would not start. After several attempts of cycling on off etc it would at random start and the same series of events would insue.

I've checked the EFI fuses and relay, I replaced the fuel pump because of all the symptoms fuel pump would make a good suspect. I switched out the EFI 4 pin relay with one under the kick panel. All of this, same issue exists.

What am I overlooking? Anyone ever have these symptoms ?

I'm supposed to be leaving Atlanta Ga this Thursday for a 30 day road trip to Alaska so needless to say I'm desperate and a bit nervous about this...any help appreciated.

 

[Tools R Us]

With the key to run, motor off, is the CEL on?

 

[Tools R Us]

What model year?

 

[BT80]

It's a 1997
With the key in the on position there is no CEL illumination.

 

[Tools R Us]

Then, most likely there is no power to B+ diagnostic connector, or the ECU. Test and trace back to the battery, B+, if no, the connector by the distributor, of no, the EFI relay, if no, the fusible link. Report where there is/isn't power.

 

[BT80]

Correct I'm getting no power to B+ on the diagnostic port.

 

[BT80]

I have power at the EFI fuse under hood, I have power at pin "1" and "4"

 

[Tools R Us]

The big single wire connector (IIRC, red/yellow) between the distributor and intake?

 

[BT80]

Boom! That red yellow was it seemingly!
Is that power to the ECU?

 

[Tools R Us]

Boom! That red yellow was it seemingly!
Is that power to the ECU?

Yes, that is power to the B+/ECU.

 

[BT80]

I tore the whole dash out thinking it may be the aftermarket alarm the PO installed.
Man oh man am I glad that's all it was was a connector loose, when I went to check it it just unclipped as I touched it. It's firmly connected and zip tied to prevent further issues.

 

[BT80]

Thanks everyone, especially Tools R Us!

 

[sbman]

When I bought my truck at an auction some rival buyer loosened that connector after I looked at it so the vehicle wouldn't start for people when they looked at it. Took a while to figure it out! It did help keep the price down though.

 

[Tools R Us]

... was a connector loose, when I went to check it it just unclipped as I touched it. It's firmly connected and zip tied to prevent further issues.

Good deal, easy fix. Inspect it, watch it, have seen them overheat, fail, it's a heavily loaded connection.