5.0 Starting Help

I know this is probably a better question for the mustang community, but I’m at my wits end.


Here are two videos.
One, my car is starting, the other is not. This just started today. I have an in-line spark tester in line between the distributor and the coil. The first video shows nothing but cranking, and no spark. The next video was taken 2 mins later. No changes were made to the car at all. You can tell that the spark is just enough to get the car going but once it is running, it does ok.

I carry an extra TFI. I’ve tried both of them, and the situation doesn’t change with either TFI.

New plug wires. I have substitutes the old coil wire and it made no difference either.

Almost seems to me like a bad ground, but I’ve checked and agitated all my grounding straps.

thoughts?

X

https://share.icloud.com/photos/0gZU...zwE7RzR18TXMaQ

https://share.icloud.com/photos/0nLF...wMGnBd6obHSJzQ

Update:

My car was built with two switches below the dash and a start button.

I noticed that if I held down the start button before I flipped the switches It would occasionally fire off. If I could get it to fire off just right, the car would start. I started thinking about it, and it sounded like a lack of voltage or a bad ground.

So I left the switches flipped and started poking around. I noticed that when I wiggles the wiring loom that was close to the ignition coil, the fuel pump would prime (like it would when the ignition switch was flipped just prior to start). So I cut open the loom and started wiggling each wire individually. When I wiggled a black wire with a secondary color (white I think), it primed again... and every time I time I touched it it primed. I chased it down to a small plug and beyond the plug was a ground. I took apart the plug and cleaned it. Plugged it back in and taped it back together and it solved all my issues. As a matter of fact, the car runs better, idles better, and drives better.

If it gives me any more trouble, I’ll just remove the plug and wire it straight to ground.

I hope that this helps someone in the future.

Cheers,

TAttachment 115816Attachment 115816

Not sure what wiring harness you are using, but, yes the EEC is very sensitive to grounding. I think the black with white stripe is the main ground wire going to pin 60.

This is a picture of the cannon plug that was the source of the bad ground. I just removed it 100%. Took it straight to the frame (where it was before... just without the cannon plug). It’s got the stock 5.0 factory wiring harness from a 93 GT 5.0

Attachment 115923Attachment 115923