It's the crank sensor!
Join Date: Nov 2007
Location: Central Minnesota
Have you verified proper fuel delivery? If not, should do so.
For an 88, you should have 31 psi at idle. Then disconnect the vacuum line leading to the fuel pressure regulator and the pressure should jump to approx. 39 psi. Also be sure that the FPR vacuum line is pulling good vacuum and is not wet with fuel. If that vacuum line has gas in it, replace the regulator.
99 Cherokee, 4.0 AW4, NP242
Past Jeeps: 49 Willys, 81 Scrambler, 88 Comanche
Without "data", all you have is an opinion!