3f-e Intermittent throttle?/fuel? loss? (2 Viewers)

[desertdweller]

I finally got around to pulling the intake to look at the wiring harness underneath.
I did find what appears to be a suspicious looking repair to this blue wire that goes to a ground below.
So far I’ve been unable to determine what that blue wire is.

 

[red66toy]

I finally got around to pulling the intake to look at the wiring harness underneath.
I did find what appears to be a suspicious looking repair to this blue wire that goes to a ground below.
So far I’ve been unable to determine what that blue wire is.
View attachment 2868648

To the FSM wiring diagrams! is there a janky twisted wire connection under that tape?

 

[itbrokeagain]

Next time it acts up turn the key but don’t release it. I had the exact same issue in the woods. By looking at some wiring diagrams I found that the fuel pump is energized for a second by the ignition but then the afm takes over. If the afm is bad it won’t stay running but if you keep the key in the start position it keeps the pump energized.

 

[jonheld]

That is not a ground wire. That's the thermistor that runs the intake cooling fan.

 

[desertdweller]

That is not a ground wire. That's the thermistor that runs the intake cooling fan.

Did you just know that off the top of your head?

 

[jonheld]

Did you just know that off the top of your head?

Well, yea.
Even though my 91 is long gone, I did spend 25 years looking in the engine bay.

 

[desertdweller]

That wire is the only problematic looking thing I can see in the harness in that area. Looks like I’ve struck out again.

 

[jonheld]

Going back over this thread, have you verified that this is a fuel delivery issue, or a spark issue?

 

[red66toy]

@jonheld knows his stuff. That thick tab connected to the hardness that is unbolted and pointed towards the camera a bit to the left is the harness ground tab. It bolts to the intake manifold.

 

[desertdweller]

Going back over this thread, have you verified that this is a fuel delivery issue, or a spark issue?

The last time there was a no start (July 4)
I was able to verify a strong spark.

 

[jonheld]

The last time there was a no start (July 4)
I was able to verify a strong spark.

Then it points to fuel delivery. Have you bypassed the fuel pump logic as I explained earlier?

 

[jonheld]

There is also a trouble spot on the fuel pump wiring. Directly below the C pillar under the body is a connector that all fuel pump related wiring passes through. In the EWD it is connector BO1.
It is exposed to the elements and has been a trouble spot in the past.

 

[desertdweller]

Then it points to fuel delivery. Have you bypassed the fuel pump logic as I explained earlier?

Yes.
The next stop on the troubleshooting train was going to be to verify +12 at the injectors during a no start. But, I haven’t had a no start since July so I decided to have a look at the harness to see if there was anything obvious in there.

 

[desertdweller]

There is also a trouble spot on the fuel pump wiring. Directly below the C pillar under the body is a connector that all fuel pump related wiring passes through. In the EWD it is connector BO1.
It is exposed to the elements and has been a trouble spot in the past.

I have fuel at the cold start injector during a no start.