vadergator

thought i would throw this one out there and see if it stirs up any answers from someone else's personal experience. i have a 97 GC 4.0L 2WD Jeep. first, to cover all my bases for the just in case scenarios, i'll list what i've replaced to no avail to my dilemma. TPS , MAP , IAC , Cam sensor (pick-up coil) , Crank sensor , distributor cap , rotor , plugs , plug wires , coil , brand new battery registering 13.8 volts on multimeter , oil pressure switch (sending unit) , catalytic converter & muffler ( they were in need of change) , and for the hell of it , my upstream O2 sensor. they were all under warranty and it's just gotten to this point for necessary elimination of suspects. here's the deal. the motor turns over, but will not fire up. yes, the pulleys engage and make the serpentine belt turn. so, obviously i have spark. have fuel pressure as well. checked out just last week at 48 psi ( must be between 44-52). tp prove that i am getting fuel, i did a no-no and intentionally flooded the jeep. obviously, i had to pull out each plug and dry them off before re-inserting them. double checked my gaps and their still at 35. i used my multimeters (analog and digital) to check for voltage. neg. - pos. on battery (13.8 volts ) , neg. on battery to pos. on alternator (13.8 volts) , neg. on battery to pos. on starter (13.8 volts). checked for possible bad ground by using meter on neg. from battery cable ( removed from battery) to pos. on battery (13.8 volts). also, the cable toned out when putting one lead on end (off of battery) of the neg. , and the other lead to the other end attached to engine block. when i did the same test on the pos. battery cable (removed off the battery) to the end at the starter, it did not tone out and read .001 on meter. obviously the hot to the starter is not grounded, but shouldn't it still tone out? anyways, i know this is a lot of info to digest. i'm trying to make it easier to scratch things off your mental list. does anybody have a clue as to what could cause this beast to not fire up? the battery gauge drops down to between 9-10 volts on the dash board when turning the motor over. it usually holds around 12 volts. again, brand new battery with a 13.8 volts reading on the meters , and has 800 CCA to it. appreciate any input that seriously can correct this issue. what's the sense in paying insurance for a jeep that won't roll.

vadergator

i just wanted to add this. don't know if it really matters or not. when you push the lock button on the key remote, you usually have the horn honk as the doors lock and the alarm (original manufactured one) sets. the alarm has not been setting (i'm assuming) because the horn doesn't honk when you push the button. the horn does work when you push it on it's own. also, the passenger (front) door lock does not always work from the driver side control switch. i don't know if this info has any bearing or not, but i thought i would throw it out there just in case.

jnicewan

I dont see where you verified that you had spark. Did you check for batt voltage to the coil when the key is on or cranking? Did you check for spark at the plugs or plug wire ends? Well, before I started checking anything I would probably start with replacing the ASD relay or at least swapping it out with another known good relay in the fuse box under the hood.

You only have a few things left after you verify spark. Many of the things you replaced would not cause a no-start concern but could cause all sorts of other running problems. anti-theft would still allow engine to start/run for a couple seconds too.
Here are a couple other possible problems
1. Bad fuel (water or contaminated etc.)
2. PCM
3. base engine problem (lack of compression)
4. timing, distributor out of phase or cam chain jumped