The insulation that connects with Velcro? 6 inches out on both sides of the connector? They may not look melted until you try to separate them. Then the fun begins.

 

I didn't notice any velcro, but it is the heat barrier type insulation the wires that rest near the manifold are wrapped in. Here's a pic of the part I was able to uncover with access through the engine compartment https://drive.google.com/file/d/0Bz6...it?usp=sharing

 

Did you unwrapped down to the connector and to the intake manifold? It doesn't matter if you are using E-85 fuel.

 

I just came back inside from completely unwrapping and removing all the tape from the harness connector all the way up to where it enters the manifold. All wires are in good shape and no melting has occurred anywhere. I separated every wire and spent a good 20 minutes checking each wire. Aside from being old, they look good.

Also, I'm running regular fuel. I've never run E-85 through it.

Jason

 

well, if you want to see if the issue is definitely fuel delivery, you can try to run the car with Brake cleaner sprayed at the throttle body with fuel pump relay removed.

But this sound like you are getting flooded as many suggested.
Since you have a fuel pressure gauge, why not try hook up the gauge, shut off the engine, see if fuel pressure drops. That will tell you if there is an injector stuck open.

 

The pressure does slowly drop with the ignition off, from 55 psi down to 20 psi over about 30 mins.

Jason

 

Key on or off? If shorted, it will bleed faster with the key on, might even have to jump the asd relay to supply power.

 

Yesterday I swapped the upstream O2 sensor based on the advice of a mechanic in another forum who said he has seen cases where an O2 sensor in these flex fuel vehicles will cause the computer to think it's running E-85 and thus dump too much fuel to the cylinders. This was consistent with what I was experiencing.

After replacing the O2 sensor, I started the van and it was still running pretty rough, but after about 5 miles of driving it evened out and now is running as good it was before it conked out the other morning. The temps have been ranging between -13 and 10 degrees here for the past few weeks, so I am not sure if the cold could have contributed this to coming on or if was just mere coincidence.

While the O2 sensor was not causing the computer to throw a code and seemed to be reporting data to the computer based on live OBD-II data, once replacing that upstream sensor, all appears to be normal again.

Thank you to everyone for the suggestions!

Jason

P.S. For anyone who might run across this thread in the future, here are a few tips:

• To check the injector wiring harness, I found it useful to unbolt the power steering pump reservoir
• I was able to replace the upstream O2 sensor from the top side with an O2 sensor socket and a 1/2" drive med length ratchet. It took a fair amount of force to break it free.
• When removing the O2 sensor connector, I found it easier to first break it loose from the bracket that the two plastic pins on the back of the connector are pushed into

 

Well here's one I'm bookmarking. Thanks for the great job of keeping us all in the loop. Glad to here your headache is gone.