Back fire at mid range
 

1990 xj 4.0 auto trans idle fine full throttle is good but at mid range back fires bad I've changed nock sensor air idle mixture valve throttle body TPI sensor MAP sensor distributor coil and its base checked my grounds crank position sensor is Farley new I'm stumped

Have you check your exhaust manifold. Mine have small crack in manifold and the engine stutter and backfire at 3000rpm. When the manifold have bigger crack, the engine run good, but the sound of the car become rough.. (until now the exhaust has not been repaired)

Check and go through all of cruisers tips. Just google cruisers renix tips and you'll find it. Personally indexing my distributor got mine to stop backfiring in the mid range.

How's the compression?