Engine 89 5.0 high output starting issues

Mustang5L5 said:

TFI is the gray box that's on the distributor. But if you have spark, even when it not starting, that's a good sign that those components are working.

In addition to the no start checklist, you will want to open the ECU up and check the capacitors. The fact that it runs when power is drained, and stops after a short wire might also point to ECU issues.

But start working through this

Cranks OK, but No Start Checklist for Fuel Injected Mustangs

Cranks OK, but No Start Checklist for Fuel Injected 5.0 Mustangs model years 1986-1995 A word about this checklist before you start: it is arranged in a specific order to put the most likely failure items first. That will save you time, energy and money. Start at the top of the list and work...

stangnet.com

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Thank you for the checklist I am finding it to be useful. I think ECU capacitors need to be checked. Today I removed all the spark plugs all of them were badly fouled with fuel so I cleaned them and wire whisked them. As soon as I reinstalled them the car starts up like it's brand new. I was even able to give it gas once with quick perfect response before the throttle became useless once again. Something is making way too much fuel go in to that engine so much that it's not at all capable for the plugs to fire and burn It off

Boostedpimp said:

If it were me, I would pull the ECU and open it up to inspect for any damage or leaking caps. Thus ruling the ecu out of the equation

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That's exactly what I want to do. Is there anything specific that you know about how to test each of the capacitors can you point me to any site that has the specifications of the board. I know what bad capacitors look like but possibly diagrams will be helpful