4.0 into a CJ7 and running issues

Looking for ideas here

88 4.0 into an 84 CJ7:

issue lack of power around 2400 RPM's, used to be around 4000 RPM's before it would stop pulling.

items checked and are all ok or replaced:

ECM

distributor

coil pack

battery cables

TPS

O2

Mapp

etc, this problem is frustrating to this poor guy

any ideas?

I would check your fuel pressure and also put a new fuel filter in for peace of mind. I believe fuel pressure should be around 39 psi for that year pressure regulator. After that I would start thinking about the injectors. Double check all of your vacuum lines.

kunaji said:

I would check your fuel pressure and also put a new fuel filter in for peace of mind. I believe fuel pressure should be around 39 psi for that year pressure regulator. After that I would start thinking about the injectors. Double check all of your vacuum lines.

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That was our thought also. He is swapping out the entire rail and injectors with others today........He as used ford rail mounted pump that was for an F250 with 5.7 V8.