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?