Sooooooo after reading through this post... I'm leaning towards fuel pump:
This is a question I have put out on two other forums with no results: I’m looking for some diagnostic help on my ’95 Mustang GT with a 93,000 mile 5.0 motor with a stock intake system (except for K& N filter), MAC shorty headers, and a Flowmaster cat-back exhaust. In other words, it’s a...
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The Mustang in that post was a 95' GT but the symptoms seem very similar to mine, along with the steps taken to try and address them. I'm going to stick with the Keep It Simple Stupid strategy here...
I have:
- Replaced Plugs with NGK TR6 gapped at .030 (8 lbs. is not blowing that gap out)
- Replaced Fuel Filter
- Calibrated TPS to .98
- Cleaned MAF
- Brand new OEM 02 Sensors (wouldn't impact WOT)
- Replaced Plug Wires
I really think the lack of a check engine light is pointing to weak fuel pump as well. The regulator vacuum line didn't smell of gas, and behaved appropriately at idle with the line detached. The gas coming out of the fuel filter looked clean when it was replaced. I have also heard that you can have normal pressure, but not enough volume. So for $120 and an afternoon, I think an Aeromotive 340lph is in my future.
Thoughts?