I need help i just got done putting a newer 5.0 in my 88 mustang. I started it a few times and it ran good, then when I went to set the timing it wouldnt start. I though maybe I needed to reset TDC so I did twice. The only way it will start is holding it wide open. Then once running it runs rough. Does that sound like a vaccum leak? Its is getting fuel, and i regaped the plugs, and it has MSD wires on it. Am I over looking something? Any help would be great. Thanks Adam

 

Check fuel pressure @KOEO & @KOER, EGR valve disconnected?, TPS damaged?, vacuum hose to MAP sensor, PCV hose & valve, vacuum line to brake booster, fuel pressure regulator vacuum line.

Let us know....

 

I just wanted to say thanks for your help. But the problem was i had a o2 sensor that was unplugged. I know stupid huh. But thanks for your help. Thanks ADAM