May have something to do with your computer's rev limiter as free
wheeling it in neutral at high Revolution Per Minute would be
destructive.
God Bless America, ßill O|||||||O
http://www.billhughes.com/

JimS wrote:
>
> 1994 Jeep Grand Cherokee. 5.2 liter.
> Does not hold fuel pressure. Misfires above 2000 RPM.
>
> '94 Grand Cherokee gets fuel pressure during the first
> 2 seconds. But loses that pressure almost immediately
> afterwards. Have replaced the fuel pump and the fuel
> pressure regulator. None of the fuel injectors appear
> to be leaking.
>
> Where might the loss of fuel pressure occur?
>
> The Grand Cherokee also misfires above 2000 RMP. This
> happens only with transmission in Park or Neutral, not
> in drive. It idles well and runs well up to 2000 RMP.
> At 2000 RMP and above get misfires as evidenced by
> roughness and high HC's. Misfiring is not isolated
> to just one cylinder.
>
> Have replaced the crankshaft position sensor (which was
> bad). Have replaced the coil, the cap and the rotor.
> Inspected spark plugs and they look new. Checked spark
> plug wires and they are good.
>
> What might cause misfires only above 2000 RMP and only
> in Park or Neutral?